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ssg
17th May 2008, 17:18
Assume you have 5000 ft extra runway past your balanced field length, your light, cool weather, everything is in your favor...you accelerate past V1 twards V2, and you get an engine fire...

Would you fly it off the ground or try to stop it?

planett
17th May 2008, 17:45
I would Go.

beachbumflyer
17th May 2008, 17:59
I would fly.

Wizofoz
17th May 2008, 18:01
Sorry, no brainer.

What have you briefed?
What have you been trained to do?
What would you be doing for a living now if you'd rejected after V1 in your last Sim session?

We are go-minded for a reason. A high speed reject, even under the circumstances you outline, is a high-risk manoeuve. Taking it into the air has proven to be the safest option time and again.

Now let's talk about the legal ramifications if you took it upon yopurself to reject above V1 and you ran it into the weeds- Hope the family home is held in trust!!

BluntM8
17th May 2008, 18:04
I'd continue the take off, no question. After all, the whole point of having a decision speed is to simplify things in the heat of the moment. Presumably you've formed a contract with the rest of the crew in the pre-t/o brief regarding your actions in case of emergencies - if you break it you'll create chaos and confusion. If you survive then you ought to expect a percussive debate shortly thereafter!

Blunty

pablo2973
17th May 2008, 18:14
Ok I also know the answer to that, and what I´m supose to do in the Simm, but what would have happened to the Air France Concorde if they had aborted ....? maybe someone had survived surely the ones in the hotel underneath......, I fly an ATR and most of the times we take off within the first 30% of runway ,so still left 70% and many times I wonder the same question ..... is it really safer 100% of times , whichever a/c you fly and conditions you encounter ?
Good question, thanks for posting .:D

Dream Land
17th May 2008, 18:16
I'd recommend operating exactly how you train for best results.

Cummulo Granite
17th May 2008, 18:22
This would entirely depend on if i had another engine:ok:

SNS3Guppy
17th May 2008, 18:22
Assume you have 5000 ft extra runway past your balanced field length, your light, cool weather, everything is in your favor...you accelerate past V1 twards V2, and you get an engine fire...


Assuming you have 5,000 past a balanced field length, that number exists at V1...not after. The margin of stopping distance narrows at a non-linear rate with an increase in speed; go past V1 and the numbers are no longer meaningful.

Stopping distance is only part of the equation. Simply because one has runway ahead does not imply a successful rejection of the takeoff. Controllability, brake energy, directional issues all play a factor. An airplane at 130 knots is not the same airplane it was at 80 knots or 40 knots when it comes to getting stopped.

An engine fire is a controllable problem; one that need not merit the hazards of a high speed rejected takeoff as well. One might as well get in the air, as one is past the decision point, handle the problem effectively, and return to land stable and in control with ample runway ahead.

V1 is planned such that flying off with an engine failure or other problem is safe and controlled, whereas stopping is no longer part of the equation.

The engine is on fire continuously in normal operation. That the fire is outside the engine rather than in doesn't provide any justiifcation for abandoning plans mid-stream and entering into an unsafe condition in a state of panic. It's an engine fire. Worse case scenario, fuel chop it after getting away from the ground, and come back to land.

I don't know how many fires you've experienced outside a simulator, but my own experience has been that once the fire is detected, sit on your hands and count to ten, then address the problem with a workable cadence and some measured patience.

You're not going to try to throw in some ten tonne overgross takeoffs or disasters involving closed, dark, short runways again, are you?

AWACS_bhoy
17th May 2008, 18:24
Just to clarify i am no airline pilot but as soon as i read the tittle "Would you abort after V1?" i thought it was some sort of joke thread.

As i say i am no airline pilot but i know enough about the consequences and risks of aborted takeoff after V1 and i would say always GO!

SNS3Guppy
17th May 2008, 18:47
It's no joke; he's serious. The original poster has started a new thread to press his arguements from this thread: http://www.pprune.org/forums/showthread.php?t=326707

He's baiting respondants by putting the extra five thousand feet out there, trying to show that most pilots don't think, and are afraid to reject the takeoff.

He may as well have put a big safety net across the runway, or a giant pillow at the end, or even extended the hand of the almighty as a means of slowing the aircraft...all sorts of ridiculous teasers could be put there to say "but surely you'd reject if this were the case."

Fact is, V1 is established as the speed at which time for rejecting the takeoff is over, and going flying is as briefed. Time to fly.

con-pilot
17th May 2008, 18:50
The most important issue of aborting after V-1 would be brake energy limitations in my opinion. However, that being said I have operated aircraft off of 10, to 15,000 foot runways with a BFL of less than 5,000 feet. As the actual ground run distance was in the neighborhood of 3,500 +/- feet that would leave at least twice to three times of distance of runway remaining verus runway used to stop.

I feel that comes down to Situational Awareness. If I was in a lightly loaded 727 with a BFL of 5,000 feet and was taking off on a 12,000 foot runway I would discuss aborting after V-1 with the rest of the crew. However, you have to take into consideration the type of aircraft you are operating. In the 727 for an example V-1 is also V-R under most conditions. Therefore, in the 72 the point is mute because unless the reason for the abort is a major flight control malfunction or failure there is an excellent chance that after V-1 you be airborne; an entirely different situation requiring you to land the aircraft to abort, not a good idea.

But..........remember the AA DC-10 accident at Chicago. In that case putting the aircraft back down on the runway could have very possibly save many lives. Then again maybe not.

I guess the bottom line is, if in the slightest doubt, fly.

Junkflyer
17th May 2008, 18:58
You go. There are many variables to consider weight, type of a/c etc. In a heavy once you pass v-1 you're stopping data is invalid. Trying to stop 830,000 lbs from 170 knots with limited space is something I would not recommend. An engine fire can be dealt with in flight and an immediate return overweight is possible if you do not want to take the time to dump if the fire warning is still on.

mini-jumbo
17th May 2008, 18:59
Between 80kts and V1 I will stop for a fire, engine failure, smoke, structural damage, blocked runway....

If the call is GO, OR speed is ABOVE V1, I will continue the take-off.

That is what you've briefed, and that is what the other guy (we are multi crew after all) is expecting you to do.

So, there is no decision to make, because the decision needs to be made before V1.

airfoilmod
17th May 2008, 18:59
There's losing an engine, and then there's LOSING an engine, good point.

Mad (Flt) Scientist
17th May 2008, 19:07
Surely, the time for making all these decisions is before you brief the TO, while working out the speeds. At that point, if you notice that you have excess runway length, then you can (if the data exists to permit it) select a nice high V1 if you so desire, and work out in a nice calm atmosphere that you do, indeed, have the runway, brake energy, etc. to do so. Then you can brief that V1, and fly to it.

But having picked the V1 and briefed it, you've made your choice.

mini-jumbo
17th May 2008, 19:14
Couldn't agree more, if there is no issues with runway length and performance, and the figures agree, then the V1 would be the same as the VR (or on my type 3 knots less becuase the bug is 3 knots thick).

JW411
17th May 2008, 19:16
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) at V1.

The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) after V1.

The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) even when the engine and the pylon departed the aircraft and took the left wing slats with them.

Therefore, the TORA at Chicago was completely irrelevant to any decision process that the crew could possibly have made.

I flew the DC-10 for 8 years and it was not a great "stopping" aeroplane but it was a great "going" aeroplane. A lot of people were killed by decisions to stop after V1.

If you need any convincing, try looking at the Spantax DC-10-30 disaster at Malaga. All they had was a burst tyre on take-off but a decision to shut the throttles AFTER V1 resulted in the inevitable overrun on to a motorway (if my memory serves me right).

Had they continued to get airborne, they had enough fuel to fly to Tierra del Fuego in Chile and book a bunch of taxis and hotels on the way.

Once you shut those throttles, you have no more options available.

ssg
17th May 2008, 19:45
Come on Guppy...don't give it away....

So the consensus is?

Flying a burning aircraft up through the soup, fighting the fire while in the circut for single engine approach is more acceptable then simply pulling back the levers and adding some brakes.?

alatriste
17th May 2008, 20:21
If there is an excess of 5.000 feet of runway, that means that you are:
i) Taking off very very light
ii) WAT or SSLW limited
iii) Limited by very close obstacles.

For i) case you could equal V1 to VR. Let say your ATOM is 52T and your OTOM is 80T( RLW). If your actual V1 is 112 KIAS, VR 116 KIAS, Why don´t increase V1 to 116 KIAS if V1 for OTOM is 130 KIAS?
For case ii) you can increase V1 according your AFM-OMB and use an ICP procedure if approved by the manufacture.
For case iii) no solution.

In all the cases above, V1 must be calculated prior to take off, the speed must be fixed. Above V1 you must go. But remember that you can set different speed for diferent scenarios.
When I take off very light I always increase V1 tro VR, for me is much safer to RTO with an excess of 5.000 feet than became airbone with an engine failure or any other major malfuction and fly for 15 stressing minutes.
If the take off is runway limited I will stick to the normal V1 and be Go-minded

ssg
17th May 2008, 20:40
Congo plane crashes at end of runway; 85 aboard
Charles Ntirycha / Associated Press
GOMA, Congo -- A Congolese jetliner carrying around 85 people failed to take off Tuesday from an airport in this eastern town, crashing at high speed into a busy market neighborhood at the end of the runway, officials said.

Government officials initially said there were only six known survivors but later in the day an airline official said 60 people had survived. Local officials said dozens of bodies were pulled from the wreckage, though it was unclear if they had been passengers.

Smoke and flames engulfed the charred ruins of the aircraft, which appeared to have broken in two when it slammed into the rooftops of about 10 cement homes just outside the airport, destroying them instantly. Soldiers kept onlookers away after U.N. peacekeepers helped douse flames at the crash site.

"Smoke was rising from the plane," said Christian Kilundu, a spokesman for the Goma office of World Vision, an international aid group that has an office less than half a mile from the crash site. "As fire extinguishers were trying to put out the flames, I spoke to a priest who had been pulled from the wreckage. He was disorientated and had no idea what had happened."

Officials said they had no information on casualties among residents of the area.

The plane was operated by the private Congolese company, Hewa Bora, and was headed to the central city of Kisangani, then the capital, Kinshasa. Hewa Bora's Dirk Cramers said 53 passengers and seven crew were taken from the site and were at local hospitals.

Julien Mpaluku, the governor of the province, said there were 79 passengers on board and six crew members.

"We have already picked up many bodies -- dozens of bodies. There are a lot of flames, which makes it difficult to know if the bodies we are picking up are those of passengers of the plane or else passers-by or people that lived in the area where the plane crashed," Mpaluku said.

Employees at World Vision said the plane "failed to leave the ground," plowing instead "through wooden houses and shops in the highly populated Birere market."

The plane appeared to have been "totally flattened" by the impact, said Rachel Wolff, a U.S.-based spokeswoman for the organization who has been in contact with her colleagues in Congo.

World Vision employees who visited the scene of the crash said they saw at least eight bodies. Hours afterward, the market stalls where women had been selling their wares earlier in the day were still in flames, said Wolff.

A former pilot who survived the crash, Dunia Sindani, gave a similar account in an interview broadcast over a local U.N. radio station. The plane suffered a problem in one of its wheels -- possibly a flat tire -- and did not gain the strength to lift off, Sindani said.

-------

Just fly it to the fence and go...right Guppy?

tttoon
17th May 2008, 21:02
V1:

Maximum speed during takeoff at which a pilot must first make an action to stop the aircraft within the accelerate-stop distance. May also mean the minimum takeoff speed that will allow the pilot to continue the takeoff after failure of a critical engine.

So what exacty is here that you do not understand? Can't you see that trying to stop an aeroplane after this speed is extremely dangerous, and that if you start bending the rules to your specific (perceived) situation may be dangerous? V1 is the speed where it is generally safer to fly, and if everyone started to ignore this there will be a whole lot accidents that don't happen now.

also, FYI, when you think the whole world is against you, think about why that could be instead of digging in further.

Ollie268
17th May 2008, 21:33
briefings and training are there for a reason, if you brief to go after v1, you go unless you physically cannot due to control restriction...etc.
If you brief something and do the opposite well then you are single pilot in a multi crew environment, the other guy is out of the loop and wont know what your doing - much more riskier than flying as briefed and dealing with it in the air.

Cap Loko
17th May 2008, 21:36
ssg,

Interesting but obvious tread. To answer your question: yes, after V1 i would go even with 'plenty' of runway left, no doubts here..

Also having your other statements in mind regarding the so called 'late rotations', keep in mind that there are things such as stopways and clearways. In Europe (just as an example), the max clearway is 1/2 of the flare distance of the a/c concerned. That may add to the effect of watching an aircraft rotating 'late'.

Have you ever had a look in the TOSTA (Takeoff Safety Training Aid)? It also includes statistical data about high speed aborts.

regards,
Loko

ps. Sir, was it proven that the plane in the Congo crashed because of a flat tyre? If so, it would be interesting to know why it couldn't liftoff just because of a flat tire.

Pace
17th May 2008, 21:43
There was an aircraft that took off from Leeds a few years ago, cannot remember the details that well but they had a severe fire. The pilot put it back down on the runway. The fire was so intense that had he attempted to do a circuit everyone would have perished.

There was an airliner which crashed on fire in Canada because the Captain insisted on flying by the book. Once established on the ILS he aborted the landing to dump fuel 20 miles away. The first officer pleaded with him to land overweight, he ignored the first officer and everyone perished.

I fly Citations and at a runway like Heathrow where I can takeoff three times with a severe fire problem I would put it back down.

Taking V1 ? if V1 is 100 kts does that mean you abort at 99 kts but take off at 101 kts are we all computers without brains and instincts? Some Situations demand that you throw the book away and become a pilot.

pace

Caudillo
17th May 2008, 21:53
Pace are you really suggesting we tell the computers what to do rather than the other way round?

Cowboy.

Human Factor
17th May 2008, 22:02
I would stop after V1 for two reasons and two reasons only:

1) Total engine failure (no choice)

2) Unable to rotate, for example a jammed elevator (ditto)

Either situation is extremely unlikely. V1 isn't always calculated as a result of remaining runway distance. Think also in terms of brake energy or max tyre speed for example.

Pace
17th May 2008, 22:03
No :-) but I am saying there are situations where we do not act like computers which are programmed not to think?

A guy I know well recently crash landed a citation up at Edinburgh. He had severe control problems and landed on the disused runway. His touchdown speed was 210kts. He stopped before the end of the runway and didnt burst any tires.

Pace

Human Factor
17th May 2008, 22:07
His touchdown speed was 210kts. He stopped before the end of the runway and didnt busrt any tires.

Well done, that man. I'd have been interested to hear the outcome if he'd tried to stop from 150kts two-thirds of the way down the same runway.

mini-jumbo
17th May 2008, 22:13
His touchdown speed was 210kts. He stopped before the end of the runway and didnt busrt any tires.

Congratulation to that man. I thought this thread was about takeoff, not landing.

Pace
17th May 2008, 22:24
He would have gone off the end of the runway. A few years ago I was flying a nearly new Seneca five twin and had an engine failure at 200 feet after takeoff.

Three rocker shafts had sheared off due to overtorquing at manufacture.
The aircraft was at Grosse weight temps were above standard.
My training dictated that I shut down the engine and feather the prop.

The engine was still producing maybe 30% power. I instintively knew by the feel of the aircraft that if I lost that 30% power I was going down.
Although there was severe vibration I kept the thing going with one hand on the prop ready to feather if there was a loud bang.

Once up at 1000 feet with some air below I made a gentle turn and then shut the engine down.

Going by the book is not always in every circumstance the best way. I admit in a heavy airliner tolerances are smaller and power is greater so your options are more to the book but that isnt always the case.

Pace

Pace
17th May 2008, 22:36
>Congratulation to that man. I thought this thread was about takeoff, not landing.<

Yes but the arguement placed here is that a few kts over V1 will dramatically increase your stopping distance. This guy landed near the start of the runway but at twice V1 if you like and he had no choice.

Pace

SNS3Guppy
17th May 2008, 23:16
Come on Guppy...don't give it away....

So the consensus is?

Flying a burning aircraft up through the soup, fighting the fire while in the circut for single engine approach is more acceptable then simply pulling back the levers and adding some brakes.?


A high speed rejected takeoff isn't nearly as simple as "pulling back the levers and adding some brakes." For a guy who claims to be dual rated, and have "10,600 hours and 7 type ratings" you sound for all the world in your posts like an individual who has never flown more than microsoft flight simulator.

These type ratings you claim...never obtained through FSI or Simuflite? Certainly they don't teach what you're espousing. Nor does anyone agree with it. And it sounds ridiculous.

Never the less, you keep pounding out this agenda. Now you've introduced the DC-9 crash in Goma, Congo. Your article was filled with emotion and all the things that are entirely irrelevant to a serious technical discussion...but nothing of substance to add to the discussion. Let's add some then.

What you conveniently left out is that the runway is very poor condition, severely damaged by a volcano six years ago, and still not fixed. The runway is 6,500 feet long now. The runway was wet. It's surrounded by high terrain; the VOR approach involves a six thousand foot descent from overhead the VOR on the field. The crew executed a rejected takeoff on that runway, overrunning the end and causing carnage.

So you ask...

Just fly it to the fence and go...right Guppy?


Clearly rejecting the takeoff didn't do much good; 37 so far dead. However, to discuss the merits further is pointless until more details emerge. What you managed to do was inject more superfluous information which you appear to have dredged off a news report...offering nothing meaningful but drama. You do this just to cloud the issue? We don't have any useful information regarding why they did what they did, at what point in the takeoff they did it, or if they made a good decision...nothing...yet this is the evidence of your flawed case? Moreover, you're using African aviation as an example of what to do or not to do??? This is the fifth fatal crash in the Congo in the last year, and they've been banned from operating to Europe. Hardly the model example of what to do, and hardly a useful example in light of the fact that no details are presented.

'Great Spirits have always enountered violent opposition from mediocre minds."


You reckon you're a great spirit, do you? Okay, great spirit. Throw out some real world numbers. A good start will be all the successful high speed rejected takeoffs above V1 as a good faith effort to show that what you're talking about has at least a track record of success. When you're done with that, educate yourself a little bit on what really happens during a high speed rejected takeoff, and the reason that universally everyone disagrees with you. You might learn something (though it's doubtful, based on your comments here). Instead of pulling ridiculous, dramatic, irrelevant examples out of thin air, why not stick to the meat of the matter? Better yet, drop it. Your horse has been beaten dead.

mini-jumbo
17th May 2008, 23:19
Yes, but the point being he was landing at the beginning of the runway. So, if he was unable to stop, due to his fast approach speed, the overrun would have been at very low speed.

NigelOnDraft
17th May 2008, 23:39
Maximum speed during takeoff at which a pilot must first make an action to stop the aircraft within the accelerate-stop distance. May also mean the minimum takeoff speed that will allow the pilot to continue the takeoff after failure of a critical engine.This quote is the "key" :D The answer depends on whether the V1 you have is "go V1", or a "Stop V1". Traditionally, and in the majority of the posts above, a "Stop V1" is assumed i.e. a reject > V1 almost guarantees an overrun which is v dangerous.

However, frequently "we" fly to a "go V1" e.g. a light A319 off LHR with a V1 of 115K :ugh: You could get off LHR, climb to 300', then land back on and stop :sad: The problem is you rarely know what type of V1 you have, and even if you did, how far beyond it you can go before it becomes the other type of V1 :ooh:

So in round terms you have to treat it as a "go V1", and even in the scenario above, I will "go" for an engine failure > 115K with 10,000'+ remaining - that is the only "correct" action. But, in a complex / multi failure situation, a "stop" might be called for, that is what "judgement" is, and what we are paid for. NB it is not "incorrect" to reject > V1, just the circumstances in which it is warranted are not defined :eek:

NoD

Artie Fufkin
18th May 2008, 00:37
Agree with NoD that in some circumstances you could reject and stop safely above your bugged V1. (Bugged V1 is Vmcg, but high range V1 is coincidental with Vr)

In a B737/A320 type operation with typically less than 2 or 3 seconds between V1 and Vr, do we realistically have the time and/or capacity to make a judgment call of the magnitude of rejecting above V1? I was always told if anything goes wrong, sit on your hands and then calmly decide what to do. In circumstances where this is inappropriate and instantaneous reactions are required, we have well drilled and practiced memory items to be followed to ensure the safest outcome. The definitive example would surely be an engine fire between V1 and V2!

At the company I work for, we use low range V1s on the principle that statistically less accidents have occurred by continuing the take off when compared to high speed rejects.

ssg
18th May 2008, 01:57
Pace was the only one who agreed with me, he flies Citations too..I wonder if the airlines train different then corporate. Pace, I wouldn't fly a wreck into the air either, but the airline guys in here think that's a great idea...

I never felt the pressure in the Sim to go when I had a ton of runway to stop, if right after V1 something happened.....the goal was that I made a decision that kept the plane intact and kept people alive.

We all remember that right?...to keep the passengers alive?...right guppy?

Well you don't see too many crashed corporate jets that tried to go now do you...You tube is full of airliners that tried to make it though..

Hey, whatever guppy...yeah been to Simuflite Dallas 9 times, Flightsafety 4...

If You wanna fly a burning aircraft into the air when you coulda stopped, good for you...

As far as this BS about rejected take offs being dangerous it seems that the guys that roll off the end of the runway seem to walk away, it's the guys that try to fly the plane off and crash, tend to kill everyone on board....

Denti
18th May 2008, 02:52
Nowadays it is nearly impossible to have too much runway in front of you at V1, at least in the airline business. I have no idea if it is usual to reduce your thrust on GA aircraft with the same tools on a regular basis as we do in the airline business.

Even in a nearly empty 737-700 we have a Vr in the red lights on a 4000m runway, but we usually use improved climb, fixed derate and assumed temperature, it saves millions over the course of a normal year even on a small fleet.

If i can really do a reject precisely at V1, the best i could do was a stop 180 ft short of the end of the runway, but only if i have both engines and use full reverse which is not part of the approved performance figures. Just missing a "small" item like raising the speedbrakes will certainly lead to leaving the end of the runway at 70kts, not a nice thing to do. Just waiting until 2 seconds after V1 with the start of the RTO manouver will lead to the same result. Even more interesting, a blown tire but otherwise a perfectly executed RTO with 2 engines running and full reverse thrust will still lead to leaving the runway at 45kts.

And yes, using the wrong numbers like dry performance on a wet runway is very unpleasant as well. Real engine failure close to V1 and perfectly executed RTO with reverse thrust at dry V1 on a wet runway will lead to leaving the runway at 65 kts.

Those figures are very sobering and that is why we are trained to be go-minded and have to watch boeing/airbus instructional videos at least once a year stressing that point.

When comparing airline and business accident figures you have to count in the difference in numbers of sectors/hours flown per year and aircraft as well as total figures. For example a normal (longrange) aircraft in our fleet flies around 6000 hours a year and there is still space to improve that, though not by a lot.

ssg
18th May 2008, 03:57
Denti...question...

Why can't you take off max thrust vs reduced...which seems less safe...

Do you set your reduced thrust to just make the balanced field requirements?

In GA we do max thrust...if we can't make balanced field, we change flaps, reduce fuel, find a longer runway, leave at a cooler time...ect...

It's pretty common though on a rediculously long runway I might not try to get that last 2% out of the engines and fiddle with the levers, just don't need it...

mutt
18th May 2008, 05:47
ssg, you might be surprised to hear that our B777's operate at an avarage of 80% of takeoff power based on annual statistics, we can combine two forms of reduced thrust so that an individual takeoff can be conducted at approximately 55% of takeoff power on a light aircraft.

It all has to do with keeping the engine cool and prolonging its life.

Mutt

ssg
18th May 2008, 06:34
I wonder how many guys in here reduce power to extend balanced field numbers to fit long runways, then come in here and try to say that every take off is a nail biter 'because that's how it's done in the airlines"

Well yeah...I could take off with 50% power too, burn up 12000 feet of runway, rotate a thousand feet off the end and say...'I had the numbers", then wipe my brow...look back at the passenger, 'whew...just made it by the skin of our teeth'...

In corporate if you crash the plane at the end of the runway..then tell the boss you were trying to save engine overhaul costs, ... won't quite do it.

The engine saving argument is a tough sell. Having put a few engines through hot sections and overhauls, personaly going through the bid process, inspections ect, test cells....having run them easy, then harder, then right to the edge,...I didn't see a cost diff.

Here's what I want to know...does a 737 at Sea level, max weight, burn up 7000 feet of runway using max power?

Old Fella
18th May 2008, 06:47
Is ssg for real? V1 means V1. Why bother determining a V1 figure if there is any doubt about your actions in the event of it being a consideration.

You can safely abort, all other things being equal, before V1. Above V1 you must GO. Many more people have died as a result of attempts to abort above V1 than have than when the aircraft is flown off and the emergency is handled airborne.

ssg
18th May 2008, 06:53
Take a look at the guys that tried to go around vs the guys that ran off the end of the runway......now see who walked away..

Usualy when a plane skids off the end of a rejected take off roll (probably too heavy), they just slide into the grass..might make a mess of the landing gear but people walk away...

But when those guys try to fly a defective aircraft up into the wild blue...well, just google ' airplane crashes on take off' and see all the nice pics...

john_tullamarine
18th May 2008, 07:36
Guess that there exists a variety of considerations here ..

(a) the basic requirement is that the takeoff meets the Type Certification and, by inference, the relevant Design Standard

(b) rated thrust is fine, and available for those who want to use it

(c) derate/flex is fine, and available for those who want to use it when it is available from a certification (AFM) point of view

(d) no matter how anyone might want to skew the story, jets don't like the high end of the temperature range .. a few degrees cooler reduces maintenance/operating costs. I am sure that Mutt can comment on this ad infinitum

(e) use of derate/flex is only available when rated takeoff is not limiting ... otherwise rated is mandatory

(f) use of derate/flex doesn't have to be taken to the point of making a non-limiting takeoff limiting (which appears to be what is upsetting some of the posters). Although I don't know what they do now, in the early days of flexing, Qantas imposed an arbitrary 1000 ft pad to the figures to keep the crews happy (at least that was Wal Stack's story at the time ..) Similarly, any operator can impose whatever fat it may choose corporately. I did the sums for one operator for many years and the Chief Pilot and I, in co-operation, applied a variety of considered pads to various runways with corporate blessing .. the corporate side was quite comfortable with the idea of balancing the mighty dollar against maintaining a good argument for any legal conflict.

(g) equally, an operator may run the derate/flex to the nth degree to squeeze the last bit of advantage out of it .. so long as the TC/design requirements and any operational restrictions are met. Many of the posters whom we read in PPRuNe work for operators who do just this.

(h) would I have a problem paxing on an operator which scheduled limiting derate/flex ? .. Certainly not just for that reason .. provided the overall operational risk philosophy was reasonable ...

(i) certification doesn't address a bunch of multiple failures .. in the event of such a circumstance, the crew is called upon to exercise its great knowledge, experience and skill at a moment's notice (not too sure where this leaves a minimally experienced crew .. but that is the way it's going these days) .. and then the Captain has to try and justify these decisions at the eventual enquiry in painfully slow and intricate detail ... For those who have had no experience of such inquisitions, the recent Australian military BoI into the Nias mishap makes good bedtime reading. Another which comes to mind was the KingAir 200 (?) crash at Sydney years ago ... an Ansett captain operating into Sydney at the time (and patently unrelated to the crash) sustained a very lengthy cross examination at the enquiry. I am sure that most of us can cite numerous such cases.


I suspect that ssg may not have had any/much experience with derate/flex takeoffs.

For those who have, and seek to champion its benefits .. please keep in mind that folk like ssg's operator are perfectly OK to operate at rated thrust if they wish. Many years ago I worked for a government operation which, amongst other Types, operated a Dart powered bird .. which they operated wet takeoff routinely .. often running up to takeoff power on the brakes .. even when empty from long runways. Didn't do the maintenance/operating costs much good but that was their choice .. our taxes at work. Centaurus could add much comment to this as he was a Captain for that operator at the time and did his best to inject a bit of commercial commonsense into the operational philosophy .. with not a great deal of success.

ssg
18th May 2008, 08:54
Thanks for the primer on flex power...

Just because I am not one of those operators that uses flex power to 'fly it to the fence' every time, doesn't mean I don't understand how unsafe it is.

Flex power is always a choice...a choice to put 200 people as far down the runway as possible, accellerating the slowest, v speeds as close to the fence, the obsticles as near as possible, and giving the crew the least time to stop, or go, or make a decision. Flex power is a intentional way to decrease all safety margins to nil on take off to save for the intangible and hardly quantifiable benefit of saving on engine overhaul cost through operator imput.

It's no wonder that all these airline guys have a 'go' mentality...they are so close to edge, that should they lose and engine they can go, but also add 10-50% more power on thier last good engine...

Denti
18th May 2008, 09:35
Why can't you take off max thrust vs reduced...which seems less safe...


Simple, because it costs too much. We try to keep our engines on the wing for over 40.000 hours on the shorthaul fleet and we have succeeded a couple times allready. That alone saves several hundred million dollars over the lifetime of an airplane in maintenance costs. Besides, we are told (as a pilot i cannot prove or disprove that) that reduced power take offs save quite a lot of fuel, which becomes more important with higher fuel prices.

We are free however to give us safety margins if we deem it necesarry, for example we often calculate the performance figures for an intersection take off instead of full length simply because it gives us more flexibility in take off points to choose from. Or we can deselect certain things in the performance tool, some captains dont like to use improved climb so we dont use that in those cases. I can understand that, running into the red red lights before you rotate at 175kts is not really fun (boeing classic/NG).

However i would still be interested in real comparable figures about take off accidents between GA and airline business per 100.000 sectors and operating hours. Single cases as the ones you mentioned don't prove or disprove anything if you cannot set them in a statistical significant perspective of overall operating hours and sectors flown.

mini-jumbo
18th May 2008, 10:17
But when those guys try to fly a defective aircraft up into the wild blue...well, just google ' airplane crashes on take off' and see all the nice pics...SSG,

Please tell me you're not basing your arguments on google images.

Anyone remember the Thomson Fly birdstrike at MAN. They continued, flew a perfect vectored circuit to land single engine, vacated the runway and after an inspection by fire crews, taxied to stand. No drama, no heroics, just did what they were trained to do, and what they briefed to do. Had they rejected, I suspect many injuries, if not fatalities. Then, factor into the equation the ensuing evacuation, thus causing more injuries.

There's a great video on you tube and other sites of the whole event.

Old Fella
18th May 2008, 10:36
Having read ssg's posts it seems he is unaware that there are aircraft out there with more than two engines. Regardless, it seems he/she is unwilling to accept that you must Go if above V1, that derated/flex thrust take-offs are safe and that they add to engine life. There again, I suppose that the wealth of information available is somehow unable to penetrate every cranium out there.

A37575
18th May 2008, 11:00
but my own experience has been that once the fire is detected, sit on your hands and count to ten, then address the problem with a workable cadence and some measured patience.


The 10 seconds that you sit on your hands could cost you your life. You have no idea of the severity of the fire - it could even be a false fire warning. But you simply do not know. The advice in the Boeing 737 FCTM is all you can go by and that says:
"Indications of an engine fire, impending break-up or approaching engine limits, should be dealt with as soon as possible."

Don't purposely build in breathing space just because you fear you may stuff things up. There is no shortage of advice from well meaning simulator instructors or other pilots when it comes to defining engine fire action drills.

Pace
18th May 2008, 11:07
Old Fella

Every situation is different and every aircraft is different. 999 times out of a 1000 by the book is the best way but very occasionally by the book will kill you.

I used the example of a few years ago where an aircraft aborted after rotation at Leeds because of a massive fire from the engine which was burning through the wing.

Had the Pilot continued all would have perished. The Pilot and that is what we are sussed up the situation quickly and made the right decision.

The beauty of human beings is that we can think unlike computers or set procedures. With that ability to think also is the ability to make the wrong decision hence why most accidents are pilot error. To reduce that we are trained to react in a set manner which most of the time works.

In unusual circumstances you have to throw away the books and get back to being a quick thinking Pilot surely? otherwise we are no more than trained zombies or programmed computers ourselves.

Pace

clevlandHD
18th May 2008, 11:19
SSG, the accident you refer to in Goma was actualy an above V1 reject. They got airborne and decided it was safer to "return" from a few feet off the ground.

Your operator might not try to squeeze every cent he can to turn a profit at the end of the year but most do. If they don't save there, they will cheap somewhere else...

Using TOGA every TO will reduce engine reliability thus componding your odds of having and engine failure at TO.

If would push the landing instead of going around, my operator would take care of finishing me off (if,as you believe, I would walk away). Could you tell me of a well executed GA that ended with a prang?

I am happy to flex when I can and I would continue the TO above V1 unless I know for sure the aircraft won't fly! I wish you (and your estate)luck if you ever fly your airplne outside the manufaturer's parameter. The lawyers would have it easy!

Old Fella
18th May 2008, 12:22
999 times out of 1000 doing things by the book is the best way, but very occasionally going by the book will kill you, says Pace. The rejection at Leeds you cite Pace poses another question for me. You state that the aircraft suffered a massive fire which was burning through the wing. Do you honestly believe that the pilot knew the magnitude of the problem at the instant he decided to put the aircraft back on the ground? I seriously doubt that he did. Your statement that 999 times out of 1000 going by the book is the best way says it all for me. Of course we are all capable of making decisions which are not covered by the book however, smarter people than me, and I suspect you too, have determined that if the aircraft has reached the predetermined V1, and you suffer an emergency, your best chance of survival is to take it into the air and deal with it. The decision to abort, even just a Knot or two below V1, can be more likely to end in grief than to keep going. It would seem to me that the Leeds incident outcome was more "good luck" than the result of good judgement based on knowledge of the magnitude of the problem. I have no idea what you fly. I do know that in close to fifty years in the flying game I am still on the side of the "GO" brigade.

Pace
18th May 2008, 12:47
I am with a V1 brigade too with a caveat. I do not fly heavies but corporate Citations as a captain.

I had an engine failure in a twin Seneca a few years ago at grosse weight and 200 feet in the climb. Had I followed laid down procedures I know that I would not be here to write this.

Pace

Black Knat
18th May 2008, 13:04
I think the Leeds incident refered to may in fact be the 748 out of STN, en route to Leeds. The Dart engine shed part of its 'internals' (at or around V1) which ended up with an uncontained engine fire/failure. Channex had a similar thing on one of its F27's only in that incident it was at 400'.
Believe the 748 ended up off the end of the runway.

G-ALAN
18th May 2008, 13:05
I was going to bring up the incident at Manchester but mini jumbo beat me to it. Anyway here's the link to the video.

http://www.youtube.com/watch?v=9KhZwsYtNDE

Denti
18th May 2008, 13:18
Pace, remember a Seneca is not a transport category certified aircraft and therefore has different performance specs. I certainly hope that Citations are certified according to FAR/JAR 25, but as i dont fly them i don't know if that is the case.

We used that thing (seneca V) during training but shortly after i was done my flight school got rid of it due to very poor dispatch reliability and safety concerns (around 40% dispatch reliability). We flew it to full airline procedures, however we knew that there is a certain range during take off where an engine failure is not really survivable if you use balanced field length.

powerstall
18th May 2008, 13:48
in regards to the training in the sim (type rating), didn't the TRI taught us .. AT or Above V1 we continue take off?....

in case an accident does occur, doesn't the investigating body check your last recurrent or your training?

what does the "book" say?

:ugh:

GlueBall
18th May 2008, 13:56
ssg . . . if ever you transition from the Citation to the B74, your perception of aborting after V1 will quickly evaporate; even when departing at JKF's longest pavement, 13R [4442m/14572'] If you recall when many moons ago a TWA TriStar crew had aborted on 13R after V1 with disasterous consequences. :ooh:

criss
18th May 2008, 14:22
ssg, news for you - history actually knows fatal "airplane crashes on take off" caused by runway excursion due to ill-decided rejection.

"Flex power is a intentional way to decrease all safety margins to nil on take off to save for the intangible and hardly quantifiable benefit of saving on engine overhaul cost through operator imput." - sure, taking off with max power all the time does not decrease safety thru more strain on the engine.

PS. One has to admire how tolerant ppl can be in this thread.

SNS3Guppy
18th May 2008, 15:31
Since when does anybody use flex or reduced thrust to "extend balanced field length?"

From my perspective as a pilot, we've used reduced thrust where able in most types of aircraft I've flown, certainly most all turbine equipment, including agricultural, corporate/charter airplanes, and airline equipment. It's been a practice in most types of operations I've flown, from firefighting to ambulance to crop dusting/ag, to cargo, charter, corporate, government, and yes, airline. Where it's safe to do, allows ample takeoff and stopping margin, allows adequate obstacle clearance etc, it's perfectly acceptable.

A reduced thrust takeoff means that one always has the option of pushing up the power as required, though all the performance calculations take into account climb gradients, going, stopping, and obstacle clearance without having to do so. This includes an engine failure; when we calculate reduced thrust takeoff performance, the performance data assumes losing an engine and continuing the takeoff...still at reduced power, still able to make the required gradients. Stopping is a no-brainer; the power will be retarded, ground spoilers deployed, and the aircraft stopped on RTO brakes where installed, or manual braking. Not rocket science, and it's all factored in...without reverse I might add. Reverse only shortens that distance.

Our operations manual spells out exactly when a reduced thrust takeoff can be used, and when it can't. Every reduced thrust takeoff is planned with the specific runway and runway conditions in mind, including any appliable NOTAMS such as temporary obstacles or reductions in length. Every takeoff is planned with an engine failure in mind, as is the departure path after takeoff. Nothing is left to chance.

We utilize reduced thrust takeoffs, and reduced power climbs as part of the nearly universal standard noise abatement departure procedures. We also have reduced climb thrust above 10,000'.

From a mechanic's perspective, reduced engine temperatures make for substantial increases in engine and component life. I've been an aircraft mechanic and inspector as long as I've been a pilot, going back to my early teenage years. I've been working on large radial engines, small pistons, turboprops, turbojets and turbofans for several decades now. I've had these engines apart, boroscoped them, handled every internal part as a regular function of inspection and repair. The differences in operating techniques or procedures show up in burned blades, cracked cans, metal creep, etc. A ten percent reduction in power equates roughly to a ten percent increase in engine life. If this can be done safely, all the more power to the operator...increased engine life also equates to improved engine safety, longevity of components, increased mean time between failures for stressed and hard use items such as turbine wheels and blades, etc.

A common method of operating reduced thrust is to use an assumed temperature. This isn't a wild idea made up by flight crews, but comes directly from the engine and airframe manufacturers after ample testing and design. One assumes a takeoff at a much higher density altitude based on a plethora of criteria and data, and determines if the aircraft could be safely flown off the current runway under those conditions. If it could still do so, still meeting all go and stop criteria applicable to each segment of the takeoff, then it can also be taken off at a reduced power which replicates a takeoff at the higher assumed temperature. The performance data is recalculated using the reduced power to ensure it matches, and when all data adds up, the reduced power is established for the takeoff. Nothing precludes pushing up the power at any point in the takeoff where required, nor performing a full power takeoff if required. However, it isn't required, and where a reduced power takeoff is performed based on an assumed temperature calculation, an engine may be lost and the takeoff continued at that reduced power, and still meet all the takeoff criteria.

rcl7700
18th May 2008, 15:45
I would hate to be the captain who aborts after V1 and ends up off the end with hurt pax and a damaged ship. Start typing up a new resume, for a non-flying position, somewhere else.

I aborted a CRJ200 T/O 10 KIAS before V1, at about 48,000 lbs take off weight (53,000lbs max) at an airport with a 13,123ft long runway and 5,000ft MSL elevation and got the BTMS squares from green to white. This was using up all of the remaining runway and normal braking. I was shocked at how much runway we used and still got the brakes hot enough to require a cool down period. Had it been hotter and had we been heavier I think it would've been a more memorable experience. V1 is there for a reason. Once I decided to abort thought I would make it off the runway way before I reached the end.

rcl

airfoilmod
18th May 2008, 16:04
The more people misunderstand eachother (or feign ignorance to push the discussion), the longer the potential world record length of the thread. For my purpose (which I hope and pray is consistent with the regs) V1, at acquisition, means fly. The alternatives offered so far have to do with circumstances that would preclude flight, regardless. If one has no choice, it is not an "abort", which is a conscious decision, informed by circumstance. V1 is a decision that has been made prior to Brakes off.
Ignoring it is most likely the first blunder in an unfortunate outcome.

international hog driver
18th May 2008, 16:41
For us V1 is the go number irrespective

The only time that would differ is when you have lost one (no thrust) and the other is about to vibe itself into orbit and airspeed is decreasing even after hitting the go buttons cancelling any de-rate after collecting a whole squadron of birds.

If I had runway available then yes I will put it down and hope for the best, because its probably better to overrun on a flat area than …….. houses/terrain/water…… pick your poison

airfoilmod
18th May 2008, 16:58
The decision is no longer yours, it was made for you by Starlings, Wrens, etc. You are now not Rejecting anything except a high speed Taxi. If it won't fly, don't fly. Now you are a truck driver.

"If I had runway available, yes I would put it down...." Now you are trying to regain "choice". Your posit was clear, you cannot get airborne, then you claim discretion over runway availibility. Maddening. Clear, Out.

Airfoil

Right Way Up
18th May 2008, 17:11
Always entertaining when someone with no airline experience & what looks like about 3 years jet experience tells the airlines with over 50 years of operating heavy jets how the job should be done. :D

I guess thats why the Alaskan interview didn't go so well.... :{

ssg
18th May 2008, 17:30
I find it interesting how many guys in here have just chosen not to think, just do what the company tells them...

Flex Power: I did some research....not all airlines think it's safe, not all airlines think the cost in safety is worth the hopefull engine life extension years down the road. Read Johns T. post for starters. So this isn't 'how it's done' and 'seeing the red lights at the end' is not standard procedure. I knew it was boloney. Derating take off power, purposely burning up more runway, turning every take off into a 'right to the edge nail biter' is a choice...your doing it with people's lives...to save a buck...besides a plane crash is worth about a million engines....

Now I have no problem, if you have a ten thousand foot field with rated power, balanced field is 4000 ft, Flex would be 6000...big deal...but using it to fly to the fence?

Secondly, Airline pilots don't see the engine overhaul and hot section bills, I have been through all that..the bid process, boroscope reports, seen the pics,fod, bearing failures, sufidation, test cell issues...so if you want to beat me up for not being an airline pilot please don't come back and tell me you know anything about engine overhaul and hotsection costs. Getting an email or memo from corporate doesn't count.

Secondly if you go after V1 in all cases in all scenarios, best case is you will get back safely, worst case you don't. Conversely, if you abort, you will stop safely or you will use up the overun, and or/some grass beyond this.

It's simple as pie, not all planes will fly that day, but all planes can stay on the ground and plow through the grass. Do you think a decelerating plane still on the ground, plowing through the grass is more dangerous then a plane, that can't be flown that crashes is more safe?

If you are flying a disabled aircraft around the pattern, screw it up and don't make it...people die...if you do an RTO in a disabled aircraft...screw it up, you're still on the ground, plowing through the grass.

Now we can sit here and talk about airport after airport where you don't plow through the grass at the end, it's a cliff, it's the ocean, it's a burning lake of lava, whatever...we are talking about a right after post V1 cut where you have excess runway...

Time after time I see all these planes that tried to fly it off only to crash..and who knows maybe the plane was heavy, the pilots weak, they screwed up...we all know the results...in that flight, they should have aborted....

All I have ever said is that the situation warrants judgement. Like Pace stated, there are situations where you don't fly a wreck up in the air, and that decision has saved lifes...it's saved mine as well.

We can sit here and debate this ad nauseum, but judgement, or lack there of, and inability to adapt to a situation, especialy if it's not on the check list, seems to catch a pilot or two(and the passengers) every year.

If you guys just hope that all the problems in a plane are in the Sops manual...well that would be nice wouldnt it...how comforting...

Maybe you guys are trained to do what makes sense 80% of the time, they don't want you guys to think...If I was running an airline, I might feel the same way, especialy if my pilots were weak, the FO had 500 hours, the capt was new, the take offs were always derated, so the capt could add power on the last good engine...whatever..basicaly set sops so no one had to think and hire accordingly..

But when I fly I have a choice...Still here....

The fact is...Pace and I, curiously being corporate pilots...seem to be in disagreement with the airline pilots that having chosen to simply go or not go, at V1, without any consideration to all the possibilites seems silly.. Gee whiz it's a good thing I didn't give a 'would you go before V1 thread' because I could, and there are situations that would warrant this decision as well...anyone ever been commited to a take off?

Hey if you get to V1, the wing falls off, are you going to pull it up?...what if you lose a nose tire, and the plane won't accelerate, what about a catastrauphic controll failure(hard to keep on straight on the runway)...I mean I could sit here and give a hundred situations where your barreling down the runway, and the situation is so violent and nasty, you know you don't want to take it up in the air...or at least this pilot wouldn't. But you guys would and that flight would be doomed.

Personaly, V1 is a start for me...and yes...I stop before V1, and go after V1...untill the situation warrants otherwise...and have done so in both cases.

But one thing is for sure...I won't purposely limit my options by extending my take off roll, V speeds, and rotation, as far down the runway, to try to save a buck...simply put I will have less time to discern the problem, less time to react, I will be closer to those obsticles, and closer to overrunning if I have to stop...I like as much of a margin of safety that I can get...

Here's one for you guys...before deciding to use flex power...address the passengers with this...

'Hey guys, how would you feel if I pulled it off at the fence today, trying to save corporate a buck on engines?'

:)

GeorgEGNT
18th May 2008, 17:35
I'm no airline pilot, I'm barely a third through my PPL but was still fairly startled by that question.
There has been some interesting points in this thread but they're still overshadowed by the question. What is V1 there for? There are 2 sides to it, one side you take off and one you don't. Thats my understanding of it anyway.
So I'm fairly shocked a question like this has been asked but still, I'm only a wannabee lol I'll leave the debate to the drivers of the rune.

Right Way Up
18th May 2008, 17:45
SSG,
Its not a big issue. You fly your aircraft as you want & we'll fly ours as we want.

Not wanting to upset your disposition too much, but many Captains I flew with on the 747 , took their hand off the thrust levers at V1-10. :eek:

BTW have you ever seen what happens on a lightly loaded 747-400 on a full power takeoff which suffers an outboard engine failure. Another good reason for derated takeoffs.

international hog driver
18th May 2008, 17:49
Actually foils, in the sim you would not believe how many people try to fly out of the situation and try to keep hope alive rather than accept the reality and close the levers and plant it.

We have conducted this as an advanced loft, with they guys who have got all the competency and boxes ticked and there is a bit of time left in session.

About 70% try to fly it and just relocate the scene of the accident 30% put it back down---- 10% intentionally and its those who manage to plant it call for full flap, brake brake brake, thud, evacuate.

Occasionally we get one starter who manages to pull off a low level circuit on min power and its all hands flying, don’t change a thing in the configuration and turn finals < 100ft…… then select landing flap.

These guys are one offs and all to date come from a rigorous hands on flying environment

Wizofoz
18th May 2008, 18:04
ssg,

So, just out of interest, do you calculate the speed you CAN reject at for every takeoff? If you are two feet in the air do you know how much runway is needed to put it down again? You berate Airline pilots for following the rules laid down for us, so what ARE your rules? Do you brief your FO that "V1 is 112 but I KNOW that we can reject at 135".

Or do we just use the "That looks about right" rule....


You're right, we fly hundreds of people around and work for companies who lay down practices, usually in consultation with the people who BUILT the aircraft (do Cessna say to abort above V1? But then, what do they know!).

Do what you like with your coporate toy, we fly commercial aeroplanes for a living.

airfoilmod
18th May 2008, 18:10
That is very compelling, IHG. I'd be interested to know what the parameters are for the challenge. Are you saying 70% try to fly as if busting the Sim was the Risk? Or are they just having a go, attempting to launch to return? Because at the bottom of the matter is the need to contain whatever badness happens on the Aerodrome. It's one thing to risk Pax on an ego driven ride (not to mention A/C), quite another to gamble the lives of the people who complain about your sonic footprint at political meetings. Especially if the proposition definitely includes two failed powerplants. (One cold, the other full of feathers and bones.)
(We're speaking Twinops, here, OK?)

Airfoil

Screwballs
18th May 2008, 18:41
ssg, please givethe link to at least one accident report where an aircraft crashed after contining a take-off after V1, with a failure AFTER V1.

youTube and Google images don't count. Facts please.

Also, you have some weird obsession with "right up to the fence". Where does this come from? Tell me an commercial operator that rotates right up at the fence. You really have no knowledge of Flex or Reduced Thrust ops.

As already said "Do what you like with your coporate toy, we fly commercial aeroplanes for a living."

Denti
18th May 2008, 18:57
If you are flying a disabled aircraft around the pattern, screw it up and don't make it...people die...if you do an RTO in a disabled aircraft...screw it up, you're still on the ground, plowing through the grass.

The question is though, where do YOU decide if to abort or fly it around the pattern? Because at some point you have to decide it, one way or another.

And exactly to give us a formalised tool for that decision process we have a V1, a decision speed at which we have to have allready startet with the stopping process or take it into the air (except if the plane is unflyable, but in that case there is nothing to decide).

Simply put, in a balanced field calculation if you abort your take off 2 seconds after V1 with all engines at full reverse thrust you will depart the runway at 70 kts and come to rest around 600 ft past the end. Not all that bad if there is enough space. Now think of having only one engine and not using reverse on the other as assumed for certification, well you will run over at aroun 90kts and come to rest around 1000ft behind the end. If you decide to abort only one second later it will be around 1100 ft with all engine reverse thrust and around 1800ft for the certification case. You still have enough space to do that? Not to mention that the brakes will overheat considerably and the tires explode shortly after you came to rest puncturing the fuel tanks and making even more of a mess out of it (all values 733).

The alternative is to take it around on a pattern, do the immediate return checklist and plonk it down with a much lower speed at the beginning of the runway.

mini-jumbo
18th May 2008, 19:02
if you do an RTO in a disabled aircraft...screw it up, you're still on the ground, plowing through the grass.And people still die!

then a plane, that can't be flown that crashes is more safe?If the plane couldn't fly, you wouldn't have got airborne, thus there would be no choice but to abandon the takeoff.

In the majority of cases, the aircraft is flyable, therefore if above V1 you continue.

Time after time I see all these planes that tried to fly it off only to crash..and who knows maybe the plane was heavy, the pilots weak, they screwed up...we all know the results...in that flight, they should have aborted....Care to provide a list? a/c type, country, airline nationality. You seem to think you know the reason these crashes happened, but yet you keep failing to provide any factual information.

Hey if you get to V1, the wing falls off, are you going to pull it up?That would likely end up in a fireball and loss of life whatever happens, so really is irrelevant.

ssg, you fly biz jets? correct? Has it occured to you, that they are light compared to most airliners and accelerate far quicker, rotate at lower speeds, therefore use less runway.

Pace
18th May 2008, 19:04
I wonder how much the difference between attitudes of corporate jet pilots and Airline trained pilots comes more from where our backgrounds are different.

A corporate light jet pilot often comes from the route of flying light twins, often single pilot, often off airways down in the weather. He is used to dealing with situations on the hoof and on his/her own.

Airline trained pilots often progress through training straight into the controlled invironment of the airline where the pilot does not think but has to fly to set rules and procedures.

The light jet pilot again tends to have more hands on experience often from having flown dated equiptment which requires more involvement by the pilot.

Then there is the nature of the two animals/or birds. A light jet like a citation is still a light aircraft with slow takeoff and landing speeds.
A heavy has to be different as you are driving tons of hardware down the runway with tons of power.

So maybe the difference in attitude expressed here says more about where we come from and what we fly.

Pace

Screwballs
18th May 2008, 19:10
Pace, I think that is the correct conclusion.

I take offense at the comment "where the pilot does not think but has to fly to set rules and procedures." Either you mis-spoke or are just trying to be rude.

One could say the differing experience and attitudes are reflected in the number of fatalities in the commercial airline industry and the corporate jet, bizjet environment.

Junkflyer
18th May 2008, 19:19
I think the differences come from corporate pilots not understanding that flying large jets is different than smaller ones. Many lighter jets are capable of fl500 or near it. Large jets are not at any weight. Acceleration/decceleration take longer in large a/c and v-speeds tend to run higher. The v-1 decision is made by the time you reach that speed not when you reach that speed. It is already a go at that point.

ssg
18th May 2008, 19:19
Hog driver..

I was Dallas Simulfite..Citation Ultra Sim..(single pilot).end of session, passed ride, time left on sim...I said 'sock it to me, something devious'

The instructor sat back and said...'ok, here's one for ya...we get alot of guys in here that don't run the numbers right, they like to come in on fumes, so I am going to put you over Missoula, you just missed, you have 500 lbs of fuel'...you see if you can make it back around, 200 overcast, 1/4 mile vis, snow"

Well I knew he was trying to teach me lesson, that 500 lbs wouldn't make it, I would crash the plane trying, lesson learned: "carry more reserve fuel'

He gave a smile, blanked out the screen, and said 'ready?'

"Ready' I said...

The Missoula missed was set up to depart the runway environment, fly to a VOR, do a turn, come back around for the ILS...

1,2.3 go....

What I did..I cleaned up the plane, reduced power and climbed up to the GS intercept alt for the ILS in an immediate banking left turn, staying in the protected runway enviromnet (RE-TERPS)...I stayed in tight, turned Base at the GS intercept alt hitting the FAF as the GS was coming in...glided down the ILS staying a little fast incase the engines flamed out, kept the plane clean untill the last minute to keep power reduced to mininum...landed and rolled off on the taxiway...the engines flamed out...

He said 'I've never seen anyone do that before'

------------------------------------------------

I don't remember any prize that a pilot get's for reading the checklist and still crashing the plane...Yeah Hog, I was a handflyer...flew alot of junk up here in the Pacifc NW before I got into decent aircraft...

To the other posters...you can either be ahead of the aircraft and have situational awareness or not...but one thing is for sure...there isn't a SOPS manual or checklist big enough for all the things that can happen in a plane...very fluid environent. Your either ready for the unexpected or you do what others told you what to do, and hope that it fits the situation.

If you wanna believe that V1 go no go, is all there is to it, I can think of a ton of examples where going after V1 will kill you dead...every situation requires judgement...what makes sense...

Right Way Up
18th May 2008, 19:34
OK SSQ,

Lets have your ton of examples then!

SNS3Guppy
18th May 2008, 19:36
I wonder how much the difference between attitudes of corporate jet pilots and Airline trained pilots comes more from where our backgrounds are different.

A corporate light jet pilot often comes from the route of flying light twins, often single pilot, often off airways down in the weather. He is used to dealing with situations on the hoof and on his/her own.

Airline trained pilots often progress through training straight into the controlled invironment of the airline where the pilot does not think but has to fly to set rules and procedures.

The light jet pilot again tends to have more hands on experience often from having flown dated equiptment which requires more involvement by the pilot.


Where do you suppose airline pilots come from?

Over the course of my career I've flown more than my share of corporate and charter turbojet flights, special missions flights, utility flights, cargo flights, freight flights, fractional flights, etc. I find that training received from the airline flight training department meets the same standards and procedures and logic that is received from FSI or Simuflite. I was never trained at FSI or simuflite in a type course or recurrent to reject a takeoff after V1, nor would I do so.

Of course, how could a pilot flying for an airline or cargo freight company possibly have the advanced wealth of understanding of how to take an airplane off the ground like a corporate pilot could, right? I started flying ag airplanes and crop dusting as a kid, before finishing high school...and yet by your own assertion, that's probably all been washed away by the evils of the airline training I may or may not have received. You make assumptions aplenty...assumptions which aren't founded in experience to know the difference, or to even know one's target audience.

The truth is that most airline pilots come from one of two routes; military, or civillian. Military training and experience is well known, well documented, and a known quantity. Civillian backgrounds vary, but most civillian trained airline pilots have come up through the ranks instructing, flying freight, some corporate, generally charter, and eventually ended up where they are now.

Among those posting in this thread, for example, are pilots with varying backgrounds including military and civillian. You have experts on performance, aerodynamics, maintenance...all of whom have a very in-depth background in their field as well as a good grasp of aviation knowledge and experience. You have somewhat of a tainted image based on your own imaginings, and your expert background as a Cessna Citation pilot. What you seem to lack is a broad background or experience level. You may find that as your experience and background grows, your attitudes may change. You may also come to realize the ignorance of the statement quoted above.

The light jet pilot again tends to have more hands on experience often from having flown dated equiptment which requires more involvement by the pilot.


I don't know about you, but I learned to fly in a 1947 piper cub. I've flown 60 year old airplanes in a hard, working environment, and brand new airplanes with but fifteen hours on the airframe. Again, as you gain more experience you may find that your statement somewhat smacks of ignorance.

Then there is the nature of the two animals/or birds. A light jet like a citation is still a light aircraft with slow takeoff and landing speeds.


Perhaps your citation. A Lear, for example, uses speeds very near that of most Boeing equipment. It's not slow, it doesn't behave like a light airpalne, and it doesn't simply settle down and land like a 172. I flew the Piaggio Avanti...which lands and takes off at similiar speeds to the lear or other corporate aircraft...not a 172 either. Your straightwing citation doesn't necessarily equate to other corporate and business swept wing equipment. Never the less, it's time to learn to fly it like a jet, and not a 172; this includes coming to understand V1 marks the boundary between driving the car and flying the airplane.

A heavy has to be different as you are driving tons of hardware down the runway with tons of power.


Tons of power is relative. Slow acceleration, more mass. A comparison you might understand is the difference in a Cessna 206 between empty, and full. A large airplane when heavy, like most airplanes when heavy, can go from being quite capable to somewhat of a dog. Flying a light airplane is about mass management...which should be the same philosophy applied to a 18,000 lb learjet, too.

mini-jumbo
18th May 2008, 19:39
I agree, the inherent differences with (light) corporate biz jets and the airline world make this discussion meaningless. The two are always going to disagree.

In a light twin (seneca) I'd stop if I was still on the runway (there is no V1), plus at 80kts or there abouts chances are you'd stop on the runway or have a very low speed over-run. But in an airliner, above V1, I'm going, unless a catastrophic failure prevents me getting airborne.

international hog driver
18th May 2008, 20:06
Foils. I have only performed this on rear engine business jets and 737NG and before anyone out there in wallyworld thinks….. ONLY EVER IN THE SIM!:}

Program is as follows, day cavok nil wind……. Lovely they think:ok:

Medium weight, efato 1 V1+2, eng vibe 2 V1+5 (Above 4 on the NG)….. (bastard):E

Ok this is where it happens, reduce power lever = reduced vibes.

Remembering that we are now between V1 & V2 not really accelerating and nowhere near VFTO kind of waffelling and probably not yet at Vref (1.3).

737NG 70T F15 V2= 136 Vref= 152 (Vs 116)

If the punter can get a pitch angle about a6 and then baby it around the circuit with min power then they are set if they don’t overbank it while trying to tighten the circuit.

It really is a thinking exercise.

First is, is this puppy gonna fly (Y/N) Y- milk it, N- Close both leavers land straight ahead, do best you can with remaining real estate.

CANCELL THE DARN BELL:ouch:

Second is now flying, Vibes V’s Thrust, Pitch V’s Speed, (Biggest Killer)

Third is where is Vref??? Can you fly below Vref? Of course you can why not 1.15 Vs? limit your turn and bank angle (Second biggest killer)


Its not an ego trip thing, as the line swine know that it can be dome in the sim, everyone thinks that they can do it. The trick is the pitch angle and being happy to live below Vref with no power adjustment.

On the NG 78% thrust comes from the fan, 22% core, do you want any residual thrust? Of course you do on both sides! Aviate, Navigate, Communicate.

Burn baby burn, you want every ounce you can get, hence the don’t touch anything below 1500. In this circumstance you firewall it and leave it to burn.

The guys from a hands on background generally do well, the straight from school to 737 type are hopelessly lost while being addicted to VNav. Most don’t realize that you can fly safely below Vref. Or even VMCA in some of Canada's finest(F40 in a TwinOtter) I dont reccomend it though.

As Dirty Harry said once “A GOOD MAN KNOWS HIS LIMITATIONS” and that holds true here, If you know that you can fly outside the “Numbers” in a “Non Normal” that has no QRH reference then you know the machine and you leave that trick in the bag for when you are gonna need it (Hopefully never).

If you cant tell already, I too am a hands and feet man and to this day stuff I learnt way back when keeps me ahead of the pack, which is sadly something a lot of the newer folk will never learn.:ok:

ssg
18th May 2008, 20:09
Ok, I admit, I've been school, educated, so this is what I am going to do..

From now on if I can get away with it, all my take offs will be derated, I want to burn up as much runway as possible to get off the ground, because that will save my engines..

Not withstanding the horror in my boss and his wife's eyes as I slowly burn up 8000 ft to rotate off of a 9000 ft field, they get to enjoy flying right over the fence, buzzing the houses and mowing the trees with my landing gear on every climbout..ahh nothing like seeing the license plates of cars on take off as fly over someone's driveway...

uh oh....

But we have a problem on this flight...you see when I hit V1, I hit a flock of birds, a puddle of water, bad fuel, ect is starting to flame out my #1 engine, the other one I am not sure...no fire lights...

But I continue because I have the 'go mentality' confident I can bring up the remaining good engine, but it's just not coming up......but the fence is...so I horse it off the ground, and with my last good engine sputtering away, I try to pull up and miss the pre school I am about to hit, the shaker activates...

That's when I look back at the boss and his wife and say..

'I am really sorry, but I tried to save you some money on engine overhauls...this is how the airline guys do it'

'Feel Better?"

I am comforted by the calm, serene look of acceptance in thier eyes knowing that as we fly to the fiery crash, I flew like an airline pilot....

:)

Pace
18th May 2008, 20:28
SNSGuppy

You may be from the old school and have a wealth of experience of flying but I know of at least five pilots flying airlines as FOs right seat in 737s and A319s who have gone straight through flight school, done the minimum in twins to get their IR.They then went through a selection process self financed type ratings or were sponsored to type ratings and are now flying as FOs with a total of 500 odd hours.

You want to be rude and condescending and arrogant to me fine I wont loose any sleep over it.

And no NOWADAYS the route to airline pilot is not the route you took.
I suggest you are out of touch with the route to right seat in a 737/A319 Nowadays?

Pace

airfoilmod
18th May 2008, 20:32
Follow. But everything you describe is something a qualified pilot would do instinctively, without having done it on Sim. Nor would he need have done it prior to have success in the real world. V2+4, V1+1, you get what you're given, it's flyable, demonstrably. You go. Why wouldn't 70% of Sim pilots get it? Troubling it's not 100%. If after V1 nothing you did worked,(after launch, as you must), you're a soon to land Truck slowing down to Park. The ultimate outcome is a result beyond your ability to decide and effect Flight. What if 2 starts shedding parts, but is still making thrust? It doesn't matter, in real life, there are times you can't think or perform your way out of destiny. It is a Human endeavour, and subject to the slings, arrows and Fate of our realm. My first flight instructor landed his Baron on a Dept. Store many years ago, the lawsuits are still not resolved.
It wasn't his Fault, it was his responsibility.

Kerosine
18th May 2008, 20:33
This is a numbers game, like any other. The probability is that taking off after v1 with engine problems will statistically leave you with the highest chance of getting back on the ground safely. Of course SOPs cannot account for every combination of problems, yes, there may be the odd example of not following the SOP saving someones skin, it would be true to say that in those few seconds after v1 (where you might not be able to tell how bad the problem is) you shouldn't be second guessing the applicability of V1.

If there were to be a paradigm shift in the way pilots were trained ("V1 is a guide, however if you have a hunch you're in trouble, STOP") would this not results in a greater instance of runway overruns? A greater number of accidents? Overruns, incidentally, seem to be painted by SSG as an almost safe incident with the result being only structural damage and a few pax injuries. I was under the impression that fields/roads/housing estates present at the end of runways may result in rupturing of fuel tanks? Not very survivable.

mini-jumbo
18th May 2008, 20:34
ssg, really mate, how do you get out of bed in the morning? The shower head might fall off and knock you out. Or, is it even safe to sleep at night, you never know what might happen.

Seriously though, you seem to have a very vivid imagination, only you haven't considered the flip side, what if your brakes fail, the thrust leavers stick open, your brakes catch fire and ignite the fuel that you didn't know was leaking. All this happened after V1. Wouldn't you rather get airborne, and have the whole runway to stop in (by which time someone will have told you that you're leaking fuel, so you'll make an informed decision of what to do upon landing)?

international hog driver
18th May 2008, 20:34
Answer for SSG


Here's what I want to know...does a 737 at Sea level, max weight, burn up 7000 feet of runway using max power?

B737800FPPM 1.2.4

Sea Level, ISA+10 (25C)

Flap 5

7000ft

MTOW 77T
Speeds 152 154 160

Answer is Yep it will use 7000ft as MGTOW is 79T so we are weight limited


Foils.... I take it that you are your age as posted and that you have some experience. What comes as second nature to us experienced gents. Is far from the calibre of some of the newer members of the club.

One my drinking buddies here is the Head of Training Boeing Fleet for a major European carrier his opinion is that in the past decade a the quality of candidate has dropped substantially, many factors include self funding min hour type ratings and at one stage desperate shortages that saw anyone with a CPL IR and a heart beat making it into some carriers.

These guys have started in Joe Blow airlines where SOPs were rare, DEC’s were taken where they could get them and there was very little corporate knowledge passed on.

Now these guys are making it to the LHS and believe me, a lot make MINIMUM standard or competency, constantly.

Nuff said

ssg
18th May 2008, 20:34
Go get 'em Pace... This hilarious...

Hog I have numbers here on the new 737 just delivered to GOL, operates out of a 4200 ft field in Rio.. Your using Flex numbers....

http://www.boeing.com/commercial/news/2006/q3/060729a_nr.html

Nigel_the_Normal
18th May 2008, 20:36
I fly an ATR

Come back when you are on something a little bigger

Jetjock330
18th May 2008, 20:41
V1 is calculated for a single engine failure on a 4 engine aircraft. So if we are at V1 and have a dual flame out one side (bird strike, one engine takes the other out, or what ever), ABORT, we are below VMCG-2 (2 engine out same side). No chance in hell to get airborne and around again.

Min V1 on A343 is around 129kts, and with two engine out same side is around 157kts so STOP, and take what comes ahead rather than to continue rolling inverted and going through the perimeter fence upside down.

international hog driver
18th May 2008, 20:57
SSG you are probably right however that would be an NG fitted with the Short Field Performance package, and your numbers are ground roll

Your link says full payload..... yeah but no range for the Sao Paulo-Rio De Janeiro sector which is 220NM! I think i did a circuit bigger than that once!

Beer napkin figures would give a 65T MGTOW so it seems doable but you are not going very far and its no where near the 79T max we have.

Mine are factored as per JAR ops as I dont have the ground roll figures at home.

Either way it will basically do it.

Farrell
18th May 2008, 22:11
I use these two videos with my students to help explain the go / no go decision.

Part 1: http://www.youtube.com/watch?v=raCnJgDnijw

Part 2: http://www.youtube.com/watch?v=WhVVAI8drVo

Will help explain the timing etc involved in an RTO close to V1 and the possible consequences of an RTO on or after V1 - regardless of the distance available.

Pace
18th May 2008, 22:57
>Will help explain the timing etc involved in an RTO close to V1 and the possible consequences of an RTO on or after V1 - regardless of the distance available.<

Farrel

Excellent videos but I am sure he referred to "minimal runways" not regardless of distance available?

Lets be stupid and imagine a specially constructed 10 mile runway it would make the V1 debate look rather stupid.

Check but I am sure they referred to minimal runway/ but point taken

Pace

BOAC
18th May 2008, 23:08
OK, Pace, since I can no longer see ssg's posts, I'll bite. V1 is <=Vr - agreed? So, on your 10mile runway, engine fire - you land back on? Why on earth continue on fire?

Farrell
18th May 2008, 23:10
"Lets be stupid and imagine a specially constructed 10 mile runway it would make the V1 debate look rather stupid."

No, it wouldn't.

For example:

Blowing all the tyres on one bogey is going to cause more than a casual float to the side at 130+ kts. You could end up with a loss of control on the ground.

Tyre debris flying around. Hot brakes - fire.
Unnecessary damage to tyres, brakes, stress on the airframe...

You are setting yourself up for all kinds of unnecessary problems and risks performing an RTO after V1 and unless you are not confident of your aircrafts ability to fly, then you are far better off to go, get lighter and spend some time on the problem.

Pace
18th May 2008, 23:39
>Blowing all the tyres on one bogey is going to cause more than a casual float to the side at 130+ kts. You could end up with a loss of control on the ground.<

So in that situation would you rather stop on the ground or land with all blown tyres? You can hardly go into a holding pattern and blow them all up again :-)

This whole thread is becoming an ego trip fact is I lost a very experienced 20000 hr pilot friend and 3 others in my time so there for the grace of God go I or any of us.

There are tragic accidents that occur to all of us, nothing is set in stone, armchair pilots or otherwise.

At the end of the day you make a decision if its wrong you pay if its right you get away to fight another day.

Pace

thegreek
18th May 2008, 23:41
Question, but if you do have that 10 mile runway and take some more space (than usual, and because this time you have it) to slow down the airplane. Will you still cause damage to the plane.

In other words, could you just be aggresive on the reversers (till 60kt) and not that hard on the brakes (assuming that you have plenty of space to slow down) ?

SNS3Guppy
19th May 2008, 00:04
In a light twin (seneca) I'd stop if I was still on the runway (there is no V1), plus at 80kts or there abouts chances are you'd stop on the runway or have a very low speed over-run. But in an airliner, above V1, I'm going, unless a catastrophic failure prevents me getting airborne.


Now you're getting into the differences between part 23 airplanes and Part 25 transport category airplanes. Establishing V1 for a part 23 isn't standard; most don't have that capability, so it's really irrelevant to the discussion of continuing or rejecting past V1. Most light twin pilots tend to go by the rule of thumb that the refusal point is the gear in the wells, and many don't put the gear in the wells until there's no more chance landing back on the runway. That logic just doesn't work for transport category aircraft.

In other words, could you just be aggresive on the reversers (till 60kt) and not that hard on the brakes (assuming that you have plenty of space to slow down) ?

The general theory behind autobrakes; excepting maximum settings, reverse thrust doesn't decrease the stopping distance, but reduces the amount of braking required, making for cooler brakes Rejected takeoff autobrakes (RTO brakes) tend to deliver full braking pressure such that reverse is additive to the stopping distance. In general reversers aren't so much for stopping as reducing the thermal energy absorbed by the brakes.


And no NOWADAYS the route to airline pilot is not the route you took.
I suggest you are out of touch with the route to right seat in a 737/A319 Nowadays?


No, as I said before you make far too many assumptions in ignorance. I didn't tell you what I do for a living. I'm certainly not out of touch with the path to the right or left seat of an airliner these days. You, however, not being there yourself, certainly are. Think about it.

Pace
19th May 2008, 00:19
>No, as I said before you make far too many assumptions in ignorance. I didn't tell you what I do for a living. I'm certainly not out of touch with the path to the right or left seat of an airliner these days. You, however, not being there yourself, certainly are. Think about it. <

If they are assumptions in ignorance then I suggest you remove that ignorance by feeding in some information about what you do for a living??

It was you who blew your own trumpet about your vast experience and the path to airline flying and the huge experience of those who go there.
Most of us know that is not the case nowadays

It was you who decided to be rude and arrogant and make your own assumptions about myself.


Suggest you change your name to Mr EGO instead of hiding behind a cloak of mystery and know all when it suits you!

Pace

airfoilmod
19th May 2008, 00:43
Both are conscious, informed decisions made at a predetermined point in the takeoff Roll. Volition (option, choice) disappears at V1, by Statute. (Read: Regulation). Just past (actually just before according to Boeing), The pilots first attempts are to initiate aerodynamic flight, no mealy mouthed maybe. If, by misadventure or chance, the A/C will not fly, and no recourse is available to alter that fact, the crew now must immediately find every resource to erase all their acquired energy, and mitigate to their best ability any harm or damage. Do I understand the question? Because I'm happy with my answer and will fly with anyone who agrees with me.

ssg
19th May 2008, 01:21
Pace your right on track...Look ..here is what I see that is going on..

First of all we are asking opinions of guys that were hired to read a checklist and follow the SOPS that someone else gave them...we might as well debate this with thier chief pilots because these guys will spew the same blather over and over to keep thier jobs.. These guys weren't hired for thier experience, but to what the company wanted and to be trained the way they wanted. If you want thier opinion, they go to the SOPS manual...

Secondly..your right the videos were all minimun runway deals..so yeah, in a 747, on a 5000 ft field, with a lake of burning lava at the end..Boeing wants us to go...and I think they make it pretty clear the real problem with this whole scenario is the pilots, thier reaction times, ect...pilots making bad decisions...so if they can just have an easy thing...V1, go or not go...easy...just like EGWS...pull up, pull up...TCAS...traffic traffic..climb climb..they are trying to 'pilot proof' all these aircraft...

So if you tell 10000 pilots to go after V1, then when that Concorde can't climb or the tire blows out in Goma and the plane doesn't accelerate, ect ect...that's acceptable...because if you gave all these guys too much lattitude, they would probably crash more often..and they are probably right...especialy from what I am hearing on these threads.. I don't want these guys to think, just do...while I go find a pilot that can...

So it's make it simple for these guys... don't let them make a decision...V1 go or dont. And it works...right up untill they have to deal with plane out of paint that was rigged wrong, or bad gas, or nose wheel blew...a situation where these guys would just crash...

A one size fits all approach is easy, people will crash because one solution won't fit all these problems..., but maybe the powers that be understand that you can't teach judgement as well, but you can cull the heard for guys that can read a checklist and take orders...and do what thier told...reminds of the military...

You and I are independent thinkers, capts of our own jets, the responsibility lies on your shoulders and we set the tempo...safe, safer, safest.....

Thirdly: You and I know that the difference between 95 kts and 110kts for stopping distance in a Citation is minimal, so yeah if we have 6000 ft of runway left after a post V1 cut at 110 kts...I won't fly the burning wreck through the 00 layer, into the ice, onto the SID, over the mountains, fight the fire and what ever problems are developing, while trying to shoot the ILS coming back down..

They will go, it's how they were trained, they will lose thier jobs if they don't, and if the plane doesn't fly?...so be it...they did what they were told...and they died,, along with 200 people.

To thier credit, stopping an Airbus at 135kts is not the same as a Citation at 95, but then again, if I operated out of 10,000 ft international runways all day long, I might get real comfortable understanding just how fast one of those can stop. So I just don't know...but for every guy that tells me that a 737 takes 7000 ft of runway to get off...I find a link to the Boeing site where GOL is operating the new 737s out of a 4200 field and I am pretty sure they use balanced field numbers...not just fly it to the fence.. I see some posters pulling my leg, mixed in with some rationale...welcome to the internet..

Fourthly - We have this Flex / Reduced power thing...allowing them to make every take off similar to a short field, low performance, right to the edge, pull it up at the lights type of deal. Now while I know that everyone doesn't do this, some do...as indicated by a poster here, seemingly up on flex issues...
So if a guy on a ten thousand foot field had a balanced field of 5000 ft, he could RTO right after V1, but he wont...again because of training and also because he will use Flex, burn up more runway then max power would have...minimal stopping distances again...and what seems to be what they are all hoping for is that one good engine left will be able to be brought up to save the day...

Well now how many end of the runway crashes have we seen where the airliner hobbled down the road a little bit then crashed?..don't you think the pilot's firewalled whatever they had to keep it out of the dirt? You know they did, and it didn't save them...which gets us back to whether some airliners are overgross, or the pilots are putting in bogus numbers to make it look legal..or they did add that extra flex power, and it didn't work..something as simple as a blown tire took out the whole aircraft.

Fifthy - If I was to simply give these guys the benefit of the doubt, ok ...airliners are different then corporate jets...different animals, the laws of aerodynamics, physics, regs, and logic just don't apply to each other...then I am left with this very un easy feeling...that it just isn't safe to fly on the airliners....to risky...it's all right to the edge, the pilots are robots that don't think, and they can't cope with anything outside of what's on the checklist...

I mean some of these guys have slammed me for comming up with scenarios that because it's screws up thier program I am paranoid...or unrealistic...I don't think a blow tire, bad gas, or the inside of my engines are now a pet store, is a big stretch...

This isn't a slam on airline pilots some are really good...but I always thought that a pilot should be ready for the unexpected, not just sit there towing the company line, just happy to be there up in the air...waiting for something to happen and when it does, they run to thier checklist and hope the problem is on it.

So I got all the airline pilots in here upset with me again...so here's a story that should make you robots happy...

Remember the pilot who's airliner blew it's top off in Hawaii...ex F4 pilot...he had an unpressurized plane, unknown flight charateriticss...he slowly changed configurations, speeds ect to see the edge of the envelop of his 'new' aircraft...if he used company ref speeds plane would have stalled...he basicaly flight tested his aircraft, came up with a new envelope and landed safely...now that's who I want flying my airlier....

Conversely, the Alaska guys that kept fiddling with thier trim for an hour, definate worsening flight control problem...ample opportunities to land in LA, San Fran, ect...kept playing with it untill they put it in the ocean....they kept calling ops to ask what to do...

-Lastly...you can hire 1000 guys to do a basic one skill job description or you hire one guy to do it all...I tend to see a bigger picture...they see what they are told...and sit in a plane...they don't maintain it, they don't do the engines, they don't buy fuel, they don't plan the trips, ....and they are given about zero lattitide in what they do...V1 is probably the biggest decision they make all day, besides what the want in thier coffee..

Don't get bugged by someone's idea of who becomes an airline pilot, I made it to the very end with two airlines...sitting in front of the chief pilots...it's an attitude thing...not an experience thing, not a safety thing...your either a robot or not...I'm not...it's not a slam...we need drones...and we need leaders...to many chiefs and not enough indians is a problem...I'm a chief pilot, it works for me...and I have a reall problem with someone telling me to do something stupid or unsafe, inorder just to go along with the flow...don't let someone in here intimidate you into thinking they have credentials and you don't I have been dealing with 18000 hour legends for years...I stand up to them, and while I may not make alot of friends doing it..it's funny how when they get sick...I get the call from thier boss to do the trip....

You know, many of these guys don't want to be 'pilot's' but they want the seat, the title and the paycheck...

Honestly, I see some sparks of hope in here...I know guys are sitting back shaking thier heads at these posts, but they don't want to rock the boat...just fly thier planes safe...it's been a learning experience for me...I learned from all this...

So Pace...are you going to take off with 50% power, pull it up at the end, and then yell back...'hey boss, just trying to save you some money!"

:)

Over and out....

SNS3Guppy
19th May 2008, 01:26
If they are assumptions in ignorance then I suggest you remove that ignorance by feeding in some information about what you do for a living??


No, that's really the point. It was you who asserted that the airline pilot couldn't possibly understand the vast knowledge acquired by the light airplane pilot or the corporate pilot who has flown freight...there you make false and ignorant assumptions just as you assumed regarding what I or anyone else here does. Those who disagree with you the vast majority, of course) couldn't possibly understand because none of us have your overwhelming experience. Truth is, most of us do, plus our own additional training and experience. Your statement was made in ignorance. It really doesn't matter what I do for a living, nor can you simply assume that I couldn't possibly understand the mystical world of corporate flying. Many of us have flown or do fly corporate aircraft.

What any of us do for a living isn't nearly so important as sticking to true and correct information here. It was you that introduced the idea that many of us here couldn't understand you, couldn't understand a light jet, and of course you're wrong. We can, based on our own experience. Many of us have the additional benifit of multiple aircraft types from big to small, and many different kinds of aircraft operations.

It really doesn't matter; in a Part 25 transport category airplane, rejecting the takeoff after V1 is a bad idea. Transport category aircraft have the performance and capability to fly off the runway when an engine is lost at or after V1, and meet specific minimum climb gradient criteria...which makes it the reason that V1 exists.

So far as a "V1 go" and a V1 stop...no, V1 is established as the point at which stopping is no longer part of the program, no longer in the cards. That being the case, it really doesn't matter if the profile is being flown by Joe Corporate Pilot or Joe Airline Pilot. Flight Safety International, CAE Simuflite, and other well known and recognized training facilities don't teach it differently, and it's not practiced differently by knowledgeable and professional flight departments.

There are always a few characters who think they can reinvent the wheel, however, as demonstrated in this thread.

rcl7700
19th May 2008, 02:54
Wow, so pilots are only checklist readers. Must be pretty scary for some of you to be on an aircraft with two guys like that who are in charge of your safety.

The purpose of removing analysis from such a delicate instant like V1 go/no go is so that precious seconds are not wasted wondering what's best choice.

These procedures are not coming from our "cheif pilot", they come from decades of commercial aviation accident research.

I suppose going around when we reach minimums on an ILS without the runway environment in sight is just another expression of our mindless procedures.

rcl

ssg
19th May 2008, 03:15
Narrative:
Spantax Flight BX995 departed Madrid-Barajas at 09:36 on a charter flight to Málaga and New York. The DC-10 arrived at Málaga at 10:20 where 251 passengers embarked. The crew then taxied to the threshold of runway 14. Takeoff clearance was received at 11:58. During takeoff the copilot called out the 80 knots and 100 knots speeds. A short time before reaching V1 (162 kts), pieces of tread of a nose wheel tire started to detach. At or close to V1 a vibration was felt. The airplane continued to accelerate through VR. As the captain tried to rotate by applying up elevator, the vibration was of such magnitude that he feared that the plane might become uncontrollable after takeoff. He decided to abort the takeoff. At that point, with a maximum speed attained of 184 kts, there was 1295 m (4,250 feet) of runway left. The captain retarded the throttles and tried to select reverse thrust. The nr. 3 throttle slipped from his hands, causing a power asymmetry. The airplane veered slightly to the left. The Dc-10 overshot the runway at a speed of 110 kts, colliding with an ILS building, causing engine number 3 to separate. The airplane went through a fence and crossed a highway were it damaged three vehicles. It then collided with a farming construction, causing three quarters of the right wing to break off, as well as the right horizontal stabilizer. The aircraft stopped 450 m (1,475 feet) past the end of runway 14. A fire erupted in the rear of the fuselage.

PROBABLE CAUSE: "The Commission determines the cause of the accident to be the fractional detachment of the retread of the right wheel of the nose gear, originating a strong vibration which could not be identified by the captain, leading hime into the belief that the aircraft would become uncontrollable in flight, and thus deciding to abandon the take-off over VR.
The decision of aborting the take-off, though not in accordance with the standard operation procedure, is in this case considered reasonable, on the base of the irregular circumstances that the crew had to face, the short period of time available to take the decision, the lack of training in case of wheel failure and the absence of take-off procedures when failure other than that of the engines occurs."
Sources:
» Technical Report - Accident occurred on September 13th, 1982, to McDonnell Douglas DC-10-30CF aircraft, reg.n. EC-DEG, at Malaga Airport

Farrell
19th May 2008, 05:50
"So in that situation would you rather stop on the ground or land with all blown tyres? You can hardly go into a holding pattern and blow them all up again :-)"

Come on Pace......get your brain in gear.

The tyres would have blown in an attempt to get the aircraft stopped after V1.....READ what I am posting FULLY :)

ssg
19th May 2008, 07:07
Ferrel,

V1 is there to say...go or don't go...if you reject, then you have a finite amount of runway to stop the aircraft...and this is the time to do it, so you can stop while there is still pavement under you..

Posters in here seem to negate the understanding that V speeds are related to runway length and position

If you were taking off on a 10 mile deserted highway...adhering to the V speed argument is just academic....You could stay on the runway, untill limitations such as tire speed issues came into effect before lifting off...

V speeds would hardly exist without the presence of a finite amount of runway...at the core V speeds represent the concept of 'assured flight'...if you take off here, your assured of flight..if you stop here, your assured of still having pavement under you....

This where my concern with flex numbers start..that some operators will take a nice safe ten thousand foot field and bascialy fly as close to the end of it, reducing all that margin, in order to save on overhaul costs 5 years from now...with 200 people in back...

international hog driver
19th May 2008, 07:20
For the benefit of SSG

http://www.boeing.com/commercial/airports/acaps/737sec3.pdf

Page (PDF) 121 = Document 203

Fig 3.3.100

B737800, Winglets, Isa+15 (Brasil), Sea Level, 27.3K engines, NO DERATE

Now run the lines and have a look where the MTOW is for a balanced field 4300ft.

Maybe a smidge over 130K lb using F25.

So the answer is 59T nowhere near 79T MTOW?

130k lb Field Limited MTOW will let you fly the Sao Paulo-Rio De Janeiro sector as Boeing salesman talk...."max payload" ie bums on seats. However you are going to be going no further.

Now using the same figures a 7000ft BFL will give a 77T takeoff and you will go about 2500NM further.

So yes the 737 drivers who tell you they need 7000ft to go anywhere meaningful are correct

Pace
19th May 2008, 07:23
"So in that situation would you rather stop on the ground or land with all blown tyres? You can hardly go into a holding pattern and blow them all up again :-)"

Come on Pace......get your brain in gear.

The tyres would have blown in an attempt to get the aircraft stopped after V1.....READ what I am posting FULLY <

Farrel my post to you was humorous :-) Why though would you blow all the tyres applying the brakes at 135kts?

I have never suggested that in 999 out of 1000 problems that you do not continue the takeoff after V1 nor have I stated that you try and stop with 100 metres of runway remaining or any other length of inadequate runway Left. I have suggested that in certain rare conditions you have to go out of the envelope of your training and restrictions to save the day as in the Stanstead to Leeds fire where the Captain aborted with such a severe fire that the wing was in flames too.

His actions in ignoring V1 saved all the passenegers on board.

Pace

Right Way Up
19th May 2008, 07:31
that some operators will take a nice safe ten thousand foot field and bascialy fly as close to the end of it, reducing all that margin, in order to save on overhaul costs 5 years from now

and by looking after the engines makes it less likely to have an engine failure in the first place.

You seem to have the wrong idea about airline pilots. We make procedural decisions based on risk assessment made by manufacturers and authorities over many years, often learning from other peoples misfortunes. When the situation is out of the box we will make the best call to safeguard our aircraft and passengers.

Pace
19th May 2008, 07:32
>I suppose going around when we reach minimums on an ILS without the runway environment in sight is just another expression of our mindless procedures.<

rcl actually yes there are even rare occasions when that has to be done too.

I refer to one example of a KingAir 350 on a USA UK ferry where the destination and alternate went down in unforecast sea fog after passing the point of no return.

The pilots landed safely in 300 metres of fog flying the Ils to the ground and using the bug on the radar altimeter for a flare point.

There have been plenty of critical fuel situations where just that has occurred

What would you have done? sat up there till you ran out of fuel waiting for the minima to reach legal limits? Just my point.

Pace

ssg
19th May 2008, 08:35
Hog..thanks for the numbers and link.....yeah 7000 ft......balanced field..so rotation would be about what? 4000ft? So when I see 737s ROTATING at 7000 ft...do you think that might be a problem?

TWOTBAGS
19th May 2008, 09:12
when I see 737s ROTATING at 7000 ft...do you think that might be a problem?


errr no.

Have a look at figures 3.3.84

Granted that this is with CFM56-7B24 so 24K which is a standard de-rate for the larger engines. You need 9000ft BFL so being just off the ground at 7000ft ground roll is nothing new.

De-rate saves engine life, no questions there. GMI have on wing records which saves cubic $$$. Yet not all airports you can use it so no-derate for this departure, maybe you are runway or climb limited?

Boeing recommend on the NG no more than a 25% derate (Cant find the reference ATM) but given any runway contaminates or such most operators prohibit derate.

Stan Woolley
19th May 2008, 09:28
A couple of points FWIW.

Flex takeoffs don't have to be to the limit. Even at the limit there is a margin because of the actual temp being less than the assumed temp.

For example we can go 26k,24k,or 22k and within those thrust ratings a temperature flex is also available if the performance is available.

I'm a great believer in compromise in this area and generally don't reduce all the way. Many considerations may apply like runway surface conditions, runoff area,wind, MEL , is this a training flight with a cadet? etc,etc..

Also, as an airline pilot you get to fly with a great many interesting(and not so interesting)pilots from many a varied background. As a First Officer you will continually be fed information from the left seat, all of which can be useful (good and bad)even if the guy is a pain.

You do sim checks and line checks your whole career with different instructors, in my case with a number of different operators, all of whom will endeavour to improve your performance and pass on good experience.

In my short time flying a Learjet I noted that many of the Captains in that world had been so from an early stage and had not done much time in the right seat.As a result they had nowhere near such a breadth of experience and many of their ideas were self developed and guess what - nobody in the right seat was going to put them down so it must be a good idea!

I really think ssg displays these characteristics, a huge fish in a tiny bowl.

Right Way Up
19th May 2008, 09:41
Thing about this thread is that SSG opens the thread with a reasonable question, which unfortunately belies the fact that from his little world he already has the answer, and just wants to flame experienced pilots who answer that question. IMO this is not a technical discussion.:rolleyes:

bubbers44
19th May 2008, 10:14
Most airline pilots have corporate and charter experience in their background. We are not robots but we do know how to pass a check ride. Expressing non standard ideas about V1 or experiencing a wind shift close to V1 and continuing are not going to help you pass the check ride. We all know we will use common sense when this really happens. I have been told things in the sim that are company procedures but would never do if it happened that way. If it happens, you make them believe you followed company procedures, even if you didn't. Once in a while that is difficult to do, but never in my career. 23,000 hrs and no bent metal or violations doing what made sense.

Pace
19th May 2008, 10:22
>In my short time flying a Learjet I noted that many of the Captains in that world had been so from an early stage and had not done much time in the right seat.As a result they had nowhere near such a breadth of experience and many of their ideas were self developed and guess what - nobody in the right seat was going to put them down so it must be a good idea!<

Stan I would go with some of what you are saying here. Before I flew as a Captain on business jets a flew with a number of Captains as a co-pilot. The ex airline ones were great to fly with some of the others were awful and expected you there as a sack of potatoes to make the flight legal.

Some were so single pilot minded that with one in particular all I got to do was to play with a second GPS and position plot on a chart. Everything else including the radio was his. It was a soul destroying experience.

I hope I have not come across as questioning the abilities of Airline pilots or their vast experience or knowledge. That was not my intention.

Having said that we operate in a different invironment. I have done a certain amount of ferry work. One business jet in particular was a wreck I brought back from India which was old and developed more problems on route than I would like to remember. The whole nature of that type of flying is that you do have to think on the hoof more.

The airline pilot works under much stricter rules into bigger airports with the added responsability of 300 odd lives in the back so how we fly and where we come from does make a difference to how we see things.

I like to try and be as professional as possible all I have said in this flame war thread is that there are rare occasions where it is better to ignore V1 especially if the runway is long enough for the aircraft you are flying and remain on the ground even if it means taking out a hedge or two than falling into the ground from a thousand feet.

As In my example of the Kingair 350 ferry above (not my ferry btw)on a rare occasion it might be better to fly an ILS to the ground in fog, breaking landing minima, than to run out of fuel.

Ie there are rare occasions when the books have to go out of the window because they do not cover every scenario.

Pace

bubbers44
19th May 2008, 10:25
A couple of times using their procedures probably would bent some metal.

Stan Woolley
19th May 2008, 11:10
Pace

I don't disagree with you - the book doesn't cover every event but one thing is for sure it's not your day if it happens to you and I'd rather be lucky than good if it does!

BTW I flew Barons/210's in South West Africa for a short while as a youngster and the subject of performance into some strips(a dry river bed for one example) was covered by the question....... 'Has anyone ever been in and out of there in a Baron?..........Yeah! OK great lets go'
No Country for Old Men.

Wizofoz
19th May 2008, 12:16
Yep,

Barons, Navajos and Aztecs- and part of the brief was that below a certain speed, even if airborne, land ahead.

I was very thankful when I got into jets that I KNEW would fly above V1 if I lost a donkey!!

One point about reduced thrust take-offs that ssg, Pace and even a lot of the airline guys miss:-

It's Safer!!

Why?

Because the day I have an engine failure, I'm going to feel a lot better knowing the other engine hasn't spent its' life being flogged doing unnecessary full power takeoffs!!

The failure rate of airline engines is incredibly low, BECAUSE we baby them and don't use thrust we don't need. It's there when we DO need it (did a TOGA take-off on a gusty day in Dubai a few weeks ago in a light 777-200-IMPRESSIVE!!), but it makes for a safer operation if the engines are looked after.

ssg, if you want to bandy around statistics and cast aspersions on airline guys (by the way, if you never wanted to be one, why did you apply at least twice (and I'm guessing several times more??)), simply compare the fatality rates of airliners (which carry hundreds at a time) and biz-jets (a couple.).

We robots seem to be doing something right!

mutt
19th May 2008, 12:56
ssg,

Presuming that you are flying part 91 and considering that you have safely gotten off the ground without using that terrible concept of reduced thrust, how do you ensure that you will clear all obstacles in your takeoff path or safely follow the SID?

Mutt

World of Tweed
19th May 2008, 13:21
Mutt - 2 points.

Once airborne from a V1 cut you always have Max thrust available from the other engine should you need it. Now your mate isn't just going to whack the other thrust lever to the stops right immediately as this is likely to make the control situation worse but on the PFs instruction or after a prompt by the other guy he may well elect to ask for more thrust.

My company uses a Laptop based system to calculate the takeoff perf. for each flight using the conditions at the time and is fitted with a database of all the airfields, runways and obstacles located at the places we fly to and from. This takes all that into account and produces the optimum performance for all the said parameters. Ensuring that all legal climb gradients are met in the event of an engine failure.

However, the Fleet Office assesses each airfield and issues Emergency Turn Procedures for each runway should they require one. This procedure is an IMC procedure that will turn the aircraft away from the high ground in the event of a loss of thrust or any condition that might affect the ability of the aircraft to clear the surrounding terrain. In this case the SID is thrown out of the window! We would be calling MAYDAY and TELLING Atc what we are about to do. i.e. left turn trk 300 then inbound to WAL 084R (in the case of runways 05 at MAN)

These Emergency Turns are issued to the pilots through the Jeppessen plates (company customised) and are repeated in the Take Off performance program on the laptop.

TyroPicard
19th May 2008, 13:24
ssg
Fifty-one people died in the Spantax accident at Malaga. If the Captain had continued the take-off, dumped fuel, and landed below MLW they would have been alive that evening, and some of them would still be alive today.
TP

lomapaseo
19th May 2008, 13:52
Engine failures (significant loss of thrust) are not statistically related to either reduced thrust or max thrust takeoffs.

The way you use the engine on takeoff (max or reduced thrust) relates to performance deterioration (EGT margin changes over time).

Your go-nogo decison outcome after V1 is likely going to be defined in a few seconds and not something that lends itself to creativity after-the-fact. That's why your training needs to be rigourous and the outcome predictable in the before takeoff briefing.

Denti
19th May 2008, 14:41
The difference between assumed temperature and a derate is very significant. Once you derate the engine from 27k to 24k this 3k is not available to you anymore. It has become a 24k engine. In my company we don't use derates, only assumed temp. I am not sure if firewalling the thrust levers would deliver 27k.
With the assumed temperature method, the full rated thrust of 27k is always available.

At least for the plane in you Nick not completely right. Even if you derate your engine you still have the full rated thrust available, you can easily get it by firewalling or just doing a second tick on the TOGA switches.

However if you derate you assume that the thrust available is only the derated thrust and therefore you calculate all performance figures based on that thrust rating. That has some pretty serious implications as of course all control speeds (VMCG/VMCA) are based on less thrust. So you can increase the thrust to full rated thrust, however you might run out of control as the VMCG/A for the derated setting is lower than that for full rated thrust, therefore it is a big nono to increase thrust beyond the max for your derated thrust setting.

With good training that is actually a non-issue, but you have to be aware about it. We do use a mix 737 classic and NGs (and a mixed airbus fleet, 319-330), however we use derate only on the NGs although it is available on the classics as well (FMC is the same). Dunno how they do it on the airbus fleet, but im sure they use at least something similar as well.

Rhyspiper
19th May 2008, 14:51
Correct me if I am wrong but aren't you are committed to the take off after
V1? and surely if you didn't die trying to stop after V1 wouldn't you get busted and aquire a bad name thoughout the airline industry?

Ashling
19th May 2008, 15:29
Well here's my 10 penneth worth.

Your take off brief covers what you plan to do in the event of a malfunction during take off. So fly or don't fly according to that brief. If you follow what you have trained and practised you have the best chance of a successfull outcome.

However

What we cater for in those briefings, among other things, is a single engine fire/failure. If you are unfortunate enough to suffer a multiple engine failure you are now outside the scope of your briefing so are not bound by it. Prior to V1 stop and all is well. Above V1 with the loss or significant damage to 2 engines on most occasions we are now talking about making the ensueing crash survivable. Best option here is in my view is to stop if you are still on the runway or just rotated and if fully airborne try to make it to water or flat open ground.

The problem with the above is diagnosing and reacting to the above in time to make the difference. In my 4 jet time I flew with the same crew day in day out and we had a crew SOP which was if someone shouted "multiple" on the flight deck we would stop if we still on the ground even if above V1 as the call meant 2 engines had gone and our preference was to take our chances off the end of the runway.

The Nimrod accidents at St Mawgan (bomb bay fire) and Kinloss (ditching with an uncontained fire) are 2 good examples of how a crew can use their experience to successfully handle an emergency not really catered for by SOP. The Nimrod accident at Kinloss (multiple birdstrike after takeoff) also shows what can happen when you lose 2 out of 4 engines heavyweight just after take off. Again the crew and fire services did a great job in makeing the crash survivable for all but the pilots.

All we can do day to day is cover the basics and hope that if we are unfortunate enough to be caught out by by numbers that our experience and training will help us through.

SSG. I, and I am sure many others here, find the manner of your posts disrespectfull and odious. In particular your assumption that airline crew are by and large unthinking automans is risable and contemptable. Personaly I come from a military background that included operational flying in fast jets, 4 jet, and 7 years of instructing. In the military we were taught to think for ourselves but also the key importance of following procedure and technique so that under pressure you make the right judgements. I have flown with many non mil commercial pilots and have the greatest respect for the vast majority and have learnt a great deal from them that has aided my successfull transition to commerial aviation. The majority are hard working and conscientious and eager to learn and improve. I have met very few unthinking automans. I am sad for you that you were unable to get the jobs you interviewed for but given the evidence of your posting here I am far from surprised. You have attitude/supervisory problem stamped all over you. Perhaps one day you will be ready but not until you learn a bit of humility and respect.

Pace
19th May 2008, 16:43
This accident was not a stop after V1 but a re landing on the same runway??
Any thoughts on this one?

Pace

>>A pilot's unorthodox handling of an engine-fire emergency on a plane carrying the Leeds United football team has been backed by air investigators.
They ruled that Captain John Hackett made the right decision immediately to re-land the aircraft rather than climb away and land later.

The Leeds United team was returning from a match at West Ham on 30 March 1998 when they were caught up in the drama on the Emerald Air flight from Stansted Airport.

The Air Accidents Investigation Branch (AAIB) report concluded it had been sensible for Captain Hackett to take over the controls from his less-experienced co-pilot.

Evacuation drills

Captain Hackett managed to get the Hawker Siddeley 748 turbo-prop aircraft back down on the runway after a fire broke out in the right-hand engine.

All 40 passengers and four crew on the flight escaped safely.

The AAIB report said the crew's actions in getting everyone out of the aircraft without fully completing the evacuation drills were "understandable in view of the severity of the fire".

The accident happened at 2330 GMT when the engine failed just after take-off for Leeds Bradford airport.



Captain Hackett: "Split-second" decision


Co-pilot Garry Lucas, aged 33 at the time, was at the controls when he and Captain Hackett heard a sharp bang.

Chief stewardess Helen Dutton, then also aged 33, told panicking passengers to sit down and advised the pilots that the right engine was on fire.

The AAIB report said that in a situation of this kind normal procedure would be for the pilot at the controls to take the plane into a climb while the other pilot went through an emergency check list.

Then the plane could be positioned to land at the departure airport or at an alternate spot.

But the report added that the sequence of events involving the Leeds plane was not "a classic scenario" and that Captain Hackett had decided to take control and re-land.

Engine fatigue

The AAIB went on: "The decision to re-land had to be made rapidly with the information available to him at that instant.

"This decision was sensible in the circumstances, as was his decision to take control from the competent but far less experienced first officer [Mr Lucas]."

The report said that at the time of the accident, Mr Lucas had had 250 hours experience on HS748s, while Captain Hackett had 3,950 hours.

Making 19 safety recommendations, the report said the Dart engine had failed because of fatigue-cracking of the high pressure turbine disc.

Dramatic event

There had been four similar failures of Rolls-Royce Dart engines over 26 years, and one since - in June 2001, said the report.

Leeds United manager David O'Leary - who was assistant manager at the time - helped in the evacuation and was praised for his actions at a news conference the crew held a few days later.

Captain Hackett, from Derbyshire, had said at the April 1998 news conference: "It was a split-second decision. Normal procedure would have been to do a complete circuit, but our judgment was that we did not have the time.

"We landed on the available runway. Unfortunately it was a little too short.

"The plane ran on to the soft ground and the nose wheel detached, making the event seem more dramatic than it probably was."<<

BOAC
19th May 2008, 17:27
Tyro - you may have gathered that I do not see ssg's posts (by choice:ok:), but is he trying to use that as an argument FOR aborting above V1? 51 dead?? As I recall the a/c was going like a train at the time:eek: I cannot recall what the accident findings were.

Re the STN 748, I believe there was found to have been a strong possibility that continued take-off and circuit to land would have resulted in the wing detaching downwind, so severe was the damage and fire. A 'lucky' call in my book. Had it gone badly wrong......................

How are you, John, if you are looking?

ssg
19th May 2008, 17:51
Ashling, In your world, planes always fly After V1, only the firelight goes on in the sim, so that should apply to the real world right? As someone who takes guys up in thier own jets and does real world V1 cuts, I can tell you that I am on the look out for that fuel problem, TR deployment, birdstrike, or some idiot on a crossing runway, that might force me to stop, accelerate, whatever to get out of his way...I could sit here and give example after example, after example of how your day will be screwed up adhering to a one fix solution to handle a world of possibilities. If you believe for example, that you can fly out with two TRs deployed right after V1 like another guy did, you will end up like him. RIP

There is a serious 'let's stick out heads in the sand' mentality in here that shouldn't be in the cockpit of any plane, much less an airliner..

I am starting to think that by being in here, my IQ is dropping...

Mutt: Gear up, V2 untill 1500 ft or clear of all obsticles.(second seg)..then V2+10, flaps up...off we go...

mutt
19th May 2008, 18:25
clear of all obsticles.(second seg) Please expand on this.. how do you know that you have cleared all of the obstacles? Do you adjust your takeoff weight for these obstacles, if so, how? 2nd question, how do you know that you can comply with the SID, 3rd Question, how do you know that you can comply with the MAP Gradient?

World of Tweed, thank you for taking the time to explain how things work in the airline world.... Now i want SSG how he does this under FAR91.

Mutt

Kerosine
19th May 2008, 18:35
SSG, re stop after V1. Why do you hold such resentment against SOPs? Why do you consistently argue against what millions of hours of flying and decades of aircraft investigation have proven? Are you trying to stand out as an 'outside the box' thinker that will revolutionise air travel?

See, here's the important bit... You don't own the planes, your don't run the airline, you don't won the company, you are not the 'boss', you do not have free reign over your aircraft to do as you please regardless of SOPs, you do not make the rules. You are trained (and paid!) as a pilot to think and act according to the situation in hand, but always within boundaries. Those boundaries are set by people that have more experience, knowledge and reliable statistics than you.

Re Flex Power, your repeated attempts to exaggerate the seriousness of this procedure 'flying up to the fence' only serves to stir it up, it does not make your point more valid. As mentioned by a few, they are not flown to the fence. Besides, this concept only bothers you because you advocate the use of the 'stop after v1' idea, so you certainly would like max power from the beginning to give you that extra runway before you 'plough through the grass'.
Please don't turn this into a 'Oh god think of the passenger safety!' issue. There will always be a balance between cost and safety, to think otherwise is naive. To say that airlines are prioritising cost saving over safety is wrong, they are merely balancing them. If we were to go with your paranoid philosophy on safety, I can't imagine your airline would last long in the competitive market.

PPRuNe is where you are free to express opinions and discuss (within reason), however your are in preaching mode. Very few agree with you, I suspect the majority never will, and this might be for a reason don't you think? Or is it a case of brainwashed robots again? Hm can never tell. To top it all, you're discussing a procedure for large jets with airlines pilots... You're not an airline pilot!

I always enjoy a heated discussion, especially when it comes to technical and safety related issues, however you keep repeating the same points over and over (3 threads and counting) and I can't help thinking you're feeling a bit desperate. Then again, I may be completely wrong, you have some further interesting points and arguments to make, it's just taking you a while to get there.

Pace
19th May 2008, 19:06
Ashling I pasted the report on the 748 re-landing. This was not just a after V1stop but an after takeoff relanding on the remaining runway. Yes there was a severe fire with the wing alite but had the Captain followed normal procedures they would have not made a circuit back to a safe landing.

That is one of the extreme situations where the guy made the right choice.
I would not pitch my miserly 3600 hrs against some of you guys who have had many thousands of hours and diverse experience but maybe part of the problem here is that I fly as a Captain on Citations/Slowtations :-) Like the 748 they are both short field aircraft compared to most Heavies.

At Heathrow I know I could probably take the Citation off or land it three times so V1 will occur around a third down the runway. That itself may colour judgement which makes a stop situation not so clear cut as tons of heavy metal hitting 170kts before rotation.

Pace

airfoilmod
19th May 2008, 19:15
When gentlemen are arguing about what amounts to the "same thing" eg are unaware that they agree in general, more and more bizarre examples are offered. Those who insist they have "discretion" to reject after V1 really do, but only if the aircraft is unflyable; those who insist V1 means take-off are also correct, and I hope would admit when they have no choice, must do anything and everything to arrest the progress of the flight in a safe manner, to the extent of the crew's training and the incident circumstances. This is what I see having read this thread through.

ATB, Airfoil

ssg
19th May 2008, 19:43
Your right Kerosine....let's not consider the passengers...what do they matter?

All I have ever said...I just think it's stupid to fly a burning uncontrollable wreck through the air, when I had 7000 ft of pavement ahead of me and a 100 miles of flat Iowa cornfields beyond that..

--------------

Mutt - Using max conintous power on take off I might have to reduce fuel(weight) to make whatever is the most limiting to be legal..usualy second segment climb gradient....I think it's safe to say that for second segment, that if I needed 2%, and I am doing 4000 ft/m in the climb I am doin ok..

But to be sure, with the radar alt climbing away, EGPWS showing clear terrain, I show right where I should be on the SID at the the right alt.(SA).using a variety of RMIs, FMS, EFIS tubes depicting VOR/DME and FMS /GPS info..

That answers your first two questions.

Missed Approach Gradient. This is based on standard aircraft performance specs...about a 2% climb gradient, the minimum...

Part 25 aircraft have to be able to do this...if the MAP is non standard...take Missoula MT for instance..down in a Valley...I have the NAPTN ILS appr. approval to fly down to 200 ft on the ILS vs 1200 by the way......because I proved to the FAA that my jet, single engine will climb out of there with thier non standard climb gradient on the procedure, which is higher...

Happy?

:)

Ashling
19th May 2008, 19:48
Pace

What I was driving at when I said what you quoted was not that you stick blindly to normal procedures when you become aware the nature of your emergency goes outside what your SOPs, briefing and experience to date cover. What I meant was that you hope your experience and training to date and all the experience you have gained along the way will help you identify when you need to step outside the box and then help you take the correct decisions.

Is that any clearer? Probably as mud.

No SOP, briefing or checklist can cover every eventuality. Just the most probable. Anyone supposing you can is rather naive.

The above said I still firmly believe that you should fly what you brief. So with a normal engine failure or fire (if such a thing exists) I would continue above V1.

I'm afraid I'm not that up on the 748 accident although I am aware of it. On the face of it the Captain made the right decision in my view and is to be applauded.

I think the 748s engines are wing mounted aren't they? rather than pod mounted as in most jet aircraft. Will make a difference with a catastrophic failure/fire. An uncontained fore spreading to the wing in a pod mounted engine is much less likely.

I will usually try to visualise an airborne turnback onto reciperical or a cross runway in case I do get an uncontained fire. Top Tip if its an airborne return onto reciperical turn with the wind initially then back into it. This will reduce your risk of flying thru the centerline and needing to increase bank late on in a tightening wind to try to line up.

Also worth checking with the crew if your fire warning goes out as it may be the fire wire has burnt through and the fire is still burning.

Kerosine
19th May 2008, 19:49
All I have ever said...I just think it's stupid to fly a burning uncontrollable wreck through the air, when I had 7000 ft of pavement ahead of me and a 100 miles of flat Iowa cornfields beyond that..
How bizarre. This thread is going downhill. Fast.

mutt
19th May 2008, 19:51
and I am doing 4000 ft/m in the climb I am doin ok..4000 ft on a single engine, max weight on a hot day? What type of Citation are you flying?

As for the SID, do you plan you escape route before takeoff or wait until you are in the SID? Does you FMS actually show the departure path based upon a single engine?

Mutt

Ashling
19th May 2008, 20:21
SSG. So you take people up in the REAL world and do V1 cuts. Gosh your hard I'm just so impressed. I used to fail peoples only engine after take off. Guess that makes me harder. (sarcasim guys. I don't think I'm hard)

No planes do not always fly after V1. My view on that is made quite clear in the post to which you refer. There is even an example of such an occurance for you. However in the vast majority of failure situations they will quite happily fly if the crew apply their training.

I clearly stated in my earlier post that if your failure goes outside what you briefed then you can act as you see fit to deal with the situation. Do try to read there's a good chap.

So if both my thrust reversers deploy above V1 (an unbelieably unlikely event) I stop. If I'm airborne I try to put it down were I can after probably shutting down both engines. If a truck/plane crosses the runway ahead of me I make a judgement of whether to get airborne over it, stop on what is left before I hit it and if I can't stop before go onto the grass as slow as I can.

ssg
19th May 2008, 20:27
So there are circumstances where you will abort after V1..
:)

groundfloor
19th May 2008, 20:38
SSG and others, please read "Handling the Big Jets" by Davies, a very humble Test Pilot who explains all this and more... That old gent Newton comes to mind as well - specifically (half mass by velocity squared). :hmm:

mutt
19th May 2008, 20:49
Mutt...classroom is finished...schools out...

Just when i was starting to have fun :):)

Anyway, I find it quite amusing that you accuse airlines of endangering the lives of passengers by using Flex Thrust, but yet you are quite happy to takeoff without doing any form of "proper" takeoff analysis that reviews the obstacles in your takeoff path or develop any engine out procedures.

Mutt

Pace
19th May 2008, 20:56
>>I'm afraid I'm not that up on the 748 accident although I am aware of it. On the face of it the Captain made the right decision in my view and is to be applauded.<<

Ashling

I did post it but here it is again :-) but it does show your point of a Captain acting quickly and thinking outside the box In the text the AAIB referred the accident as not being a classic scenario and commended him for not following post V1 Engine fire procedures. Many here argued the fact that with an engine fire you continue the takeoff. But how do you know the severity of the fire, whether it will damage controls or systems and whether you can extinguish it. Its a Hard call .My arguement throughout this thread has been totally directed at " NOT CLASSIC SCENARIOS". and especially at a STOL Citation which I could quite happily plonk back down again at somewhere like Heathrow.

Pace


>>A pilot's unorthodox handling of an engine-fire emergency on a plane carrying the Leeds United football team has been backed by air investigators.
They ruled that the captain made the right decision immediately to re-land the aircraft rather than climb away and land later.

The Leeds United team was returning from a match at West Ham on 30 March 1998 when they were caught up in the drama on the flight from Stansted Airport.

The Air Accidents Investigation Branch (AAIB) report concluded it had been sensible for the captain to take over the controls from his less-experienced co-pilot.

Evacuation drills

The captain managed to get the Hawker Siddeley 748 turbo-prop aircraft back down on the runway after a fire broke out in the right-hand engine.

All 40 passengers and four crew on the flight escaped safely.

The AAIB report said the crew's actions in getting everyone out of the aircraft without fully completing the evacuation drills were "understandable in view of the severity of the fire".

The accident happened at 2330 GMT when the engine failed just after take-off for Leeds Bradford airport.



The co-pilot was at the controls when he and the captain heard a sharp bang.

The chief stewardess told passengers to sit down and advised the pilots that the right engine was on fire.

The AAIB report said that in a situation of this kind normal procedure would be for the pilot at the controls to take the plane into a climb while the other pilot went through an emergency check list.

Then the plane could be positioned to land at the departure airport or at an alternate spot.

But the report added that the sequence of events involving the Leeds plane was not "a classic scenario" and that the captain had decided to take control and re-land.

Engine fatigue

The AAIB went on: "The decision to re-land had to be made rapidly with the information available to him at that instant.

"This decision was sensible in the circumstances, as was his decision to take control from the competent but far less experienced first officer"

Making 19 safety recommendations, the report said the Dart engine had failed because of fatigue-cracking of the high pressure turbine disc.

Dramatic event

There had been four similar failures of Rolls-Royce Dart engines over 26 years, and one since - in June 2001, said the report.

The captain had said at the April 1998 news conference: "It was a split-second decision. Normal procedure would have been to do a complete circuit, but our judgment was that we did not have the time.

"We landed on the available runway. Unfortunately it was a little too short.

"The plane ran on to the soft ground and the nose wheel detached, making the event seem more dramatic than it probably was."<<

rcl7700
19th May 2008, 20:59
So you've already made fun of TCAS resolutions, believe going below minimums is ok, and that V1 is an irrelevant figure. Do you at least wear your seatbelt?

rcl

ssg
19th May 2008, 21:28
Mutt,

If you want more detailed instruction in take off procedures, it can't be done via internet thread. It's $50 /Hr. PM me and we discuss hotel and airfare out here.

SNS3Guppy
19th May 2008, 21:29
"We landed on the available runway. Unfortunately it was a little too short.


What's seen in the Leeds incident is a matter of luck. Yes, it was a little too short. That everyone survived was luck. Continuing to post popular press renditions of aircraft mishaps is entertaining, but contributes little to a technical discussion of the facts. That the passengers on board thought the pilot was a "hero" for the successful outcome is nice...but meaningless. Imagine what the families of the deceased might have thought had he failed in his efforts. Equally as meaningless. He was lucky.

What actually happened...

The HS-748 was cleared for a runway 23 take-off at 23:29. The first officer was the handling pilot and the take-off was to be made with full dry power; the water methanol system was selected to standby. At an airspeed of 111 kt the Commander called 'vee one, rotate', the first officer moved the control column rearwards and the aircraft became airborne. Less than five seconds after the 'rotate' call, at an airspeed of 115 kt and a height of between 30 feet and 100 feet agl, the no. 2 engine suffered a catastrophic failure resulting in a sudden loss of power and an immediate substantial nacelle fire. The aircraft yawed 11deg to the right of the runway heading. The Commander took over control and the crew were told by the senior cabin attendant that the right engine was on fire. Engine power was reduced and the aircraft yawed 14.5° to the left of runway heading. Four seconds later, the sound of the engine fire warning bell was recorded. The aircraft was in the air for a total period of 27 seconds before it touched down.
The aircraft ran off the end of the runway at 62 kt., crossed the perimeter track and came to rest with the collapse of the nose landing gear.


In another case the crew had no choice but to reject above V1 because of locked flight controls. The aircraft received substantial damage in the ensuring rejected takeoff...another illustration that rejects above V1 don't go well, and that it's not nearly as simple as "pulling back the power and applying brakes."

Pace
19th May 2008, 21:31
So you've already made fun of TCAS resolutions, believe going below minimums is ok, and that V1 is an irrelevant figure. Do you at least wear your seatbelt?

rcl

You do not have to go ridiculous :-) The going below minimums was an out of the Box situation and not me. It was a KingAir 350 USA to UK past the point of no return with both airports going down in unforecast sea fog.

The pilots landed in 300 metres fog flying the ILS to the ground aided by a radar altimeter for the flare. They landed safely rather than crashing out of fuel.

Where have I implied that V1 is an irrelevant figure? Please read what I am saying

Pace

SR71
19th May 2008, 21:38
There is often a range of V1's.

If the split between them is ~30kts, cognizant of that, whats the problem with aborting post minimum V1 (but less than maximum V1)?

I seem to remember we've had this conversation before....

:ok:

SNS3Guppy
19th May 2008, 21:43
There is often a range of V1's.

If the split between them is ~30kts, cognizant of that, whats the problem with aborting post minimum V1 (but less than maximum V1)?


I can see the briefing for that one...

"We'll reject for any malfunction prior to eighty knots. Above eighty knots, we'll reject for engine fire, engine failure, loss of directional control, or any outward opening door only. After that, we'll take it airborne and handle it as an airborne emergency. Unless of course we feel like we really ought to keep it on the ground, then we'll make up our mind on the fly past V1 up to say, 30 more knots, and we might stop or we might go. I'll let you know. If we do elect to reject, I will retard the thrust levers to idle and apply reverse. We will use the takeoff autobrakes. Back me up on the speed brake handle, note the airspeed for brake energy, and notify the tower of our situation. Once airborne..."

Nope...when the precalculated and prebriefed V1 is past, so has the time for stopping. Time to make like an airplane and go fly.

SR71
19th May 2008, 21:58
Seems pretty sensible to me....

But then I've never liked reducing everything to the lowest common denominator...

This business is about keeping your options open however remote they may be....IMHO of course...

:ok:

Pace
19th May 2008, 21:58
>"We'll reject for any malfunction prior to eighty knots. Above eighty knots, we'll reject for engine fire, engine failure, loss of directional control, or any outward opening door only. After that, we'll take it airborne and handle it as an airborne emergency. Unless of course we feel like we really ought to keep it on the ground, then we'll make up our mind on the fly past V1 up to say, 30 more knots, and we might stop or we might go. I'll let you know. If we do elect to reject, I will retard the thrust levers to idle and apply reverse. We will use the takeoff autobrakes. Back me up on the speed brake handle, note the airspeed for brake energy, and notify the tower of our situation. Once airborne..."<

SNS3Guppy so you do have a sense of humour then ? :-) that was seriously funny :-) No hard feelings

Take care

Pace

FE Hoppy
19th May 2008, 23:23
SSG

I would love to know under whos authority you are allowed to teach perf?

And if you had half a clue what you were talking about you wouldn't be offering to teach people like MUTT.

SNS3Guppy
19th May 2008, 23:36
you wouldn't be offering to teach people like MUTT.


You mean Mutt, as a professional engineer, recognized in this field and an expert on this subject matter.

How odd.

galaxy flyer
20th May 2008, 03:08
SSG

I'll believe your idea about aborting after V1, IF you compute a refusal speed for each take-off, ensure it is less than or equal to maximum brake energy speed under the conditions. AND brief your crew as to your intentions, the conditions justifying an abort at the speed range between V! and Vr, assuming Vr is less than refusal speed. And inform your crew and passengers on this take-off "I have deemed the engineering data by Cessna (insert manufacturer here) to be inappropriate and will do as I deem right." Otherwise, you are just guessing your way through a dynamic physics problem by the seat of your pants.

Opinion now, your juvenile, insecure, supercilious posts are invariably written so that you can, in your own mind, belittle, denigrate professional pilots whose actions and methods have been proven over millions of flight hours and the huge efforts of experienced engineers by enterprises who are singular in their fields. These businesses, along with airlines, absolutely must, under pain of being swept aside in an accident, operate their equipment in a responsible way. Every day!!

OR they should just step aside and let you train them! :ugh:

Pugilistic Animus
20th May 2008, 03:23
I think if I have a verified engine separation--I MAY abort after V1 if i have excess RWY as you can't really be sure if the plane is still flyable as the DC-10 incident took other critical systems with it---though not likely--- as how would I verify that exactly?---also if I don't do a proper preflight and don't remove gust locks or tie down spoilers-it has happened-- so that I'd be alive for the license revocation hearing with the FAA:}


Oh yeah and will not even begin to argue with the thread's originator -unless I'm attacked myself- I prefer to read the suggestions/ opinions and advice of the industry professionals-stupid me:rolleyes:

ssg
20th May 2008, 05:19
Thanks Animas - You hit it...kind of...more simply...let's say you don't know what exactly happened...

If I see a fire light, the plane yaws over, serious vibration, heavy opposite control aeleron and rudder mputs to stay aligned with the runway...my gosh...what will the plane do when rubber isn't on the runway?

A quick glance to see 7000 ft of remaining runway left...might be an easy choice...pull the levers back, add brakes...

Who cares what the problem was..your stopped, you get the passengers out...you can now take a look...a departing C152 just put his landing gear into your left engine and tail....Glad you stopped?

BOAC
20th May 2008, 08:00
SNS3Guppy so you do have a sense of humour then - no, I think SNS3 was DEADLY serious there and trying to point out the impracticality of what had been posted. Unless we revert to a Vgo and Vstop system (used by some), there has to be a single, simple decision point. However, the Captain has the full range of options open to him/her, but:-
a) Has to be right
b) Has to justify the actions

As an aside, if any airline selectors are reading PPRune, I fear that ssg has seriously worsened the odds of ANY corporate pilot getting an airline job....just in case..........

TyroPicard
20th May 2008, 08:13
ssg
Would you care to respond to my earlier post? Here it is again...

ssg
Fifty-one people died in the Spantax accident at Malaga. If the Captain had continued the take-off, dumped fuel, and landed below MLW they would have been alive that evening, and some of them would still be alive today.
TP
TP

ssg
20th May 2008, 08:25
The Malaga accident showed that a pilot decided the plane was possibly unflyable, he made a descision. No sense arguing the point, the commission found that he made the right descion based on the info at hand...

Ashling
20th May 2008, 08:30
No SSG your the one out of step.

I doubt anyone here would say there are no circumstances in which they would stop above V1 however those circumstances would be extreme and outside of what their briefing covered.

The scenario you gave was an engine fire between V1 and V2 (VR comes after V1 by the way). You did not give more detail. So everyone here quite rightly said that they would go. That is what is briefed so that is what you do. The aircraft is designed to survive the event and we are trained to deal with it.

You then berate people for not being able to make a decision and acting like robots when in fact they made their decision calmly at the briefing stage as they should. There is one correct answer to your scenario and that is to go.

Now if you accepted that and then asked "so guys are their any circumstances in which you would stop beyond V1" you would open up a very interesting discussion. My view is that their are indeed situations were you may have no choice such as blocked runways, multiple engine failure/fire or control restriction/jam.

You have your own agenda which is every bit as blinkered as you claim us to be. If there are any recuiters out there they may well be picking up the phone to Alaskan and trying to find out who you are so they can too can make a decision.

Ashling
20th May 2008, 08:56
SSG

If you'd left it at the title then you would have got a different set of answers but you quite clearly gave us a scenario and asked for a response to it. You did not elaborate beyond that scenario and then instantly berated all of us who said continue for being robots.

We all answered your question correctly and you got all upset instead of accepting the answer and moving the discussion forward positively.

Pace
20th May 2008, 09:03
BOAC

When I first got involved in this discussion SSG brought up a serious point one that had crossed my mind a few times on takeoff in a Citation approaching V1. That was "what sort of failure would make me as a Captain decide to ignore V1 and take my chances on the ground. Or even having rotated as with the 748 fire, put the aircraft back down again. Rememeber I was talking about a citation not a 747 and a citation on a runway where it could take off or land twice.

SSG i really feel that having started a valid discussion you are now coming over as being on some sort of Ego trip, I am cleverer than you sort of thing and you cannot let go.

The problem with forums are that they are faceless text. Text can be misread, misunderstood so my apologies if any of my text has come over wrong. My thanks to all the very experienced and clever people who have contibuted to making the subject clearer and so interesting.

On that I am bowing out of this thread as it has dried up for me and thanks to everyone

Pace

SNS3Guppy
20th May 2008, 09:40
Or even having rotated as with the 748 fire, put the aircraft back down again.


The pilot got lucky. Doesn't mean he was right.

Right Way Up
20th May 2008, 09:40
No SSG,
You set the tone by asking a question then preaching/insulting experienced pilots giving you an answer. I'm not tapping out of this thread as I'm interested to see where you go from here. Having alienated your only ally in Pace in such an insulting way I look forward to your next move. :rolleyes:

pilotbear
20th May 2008, 10:01
so let me get this straight;
if you got a flap asymmetry warning, an un-commanded slat retraction, a trim runaway, an obvious control jam or hard-over, a double engine flame out, (if you only had two for the less astute among you) after V1 you would not even consider aborting the take off because you had said so???:ugh:

I have no issue with SOP's but if you cannot think outside the box you should not be in it. I am with SSG here.

ssg
20th May 2008, 10:05
Well I was sitting here, pretty much ignoring most of what you said...then my cat hopped up onto the keyboard...I got to thinking...

If all there is to a take off judgement is to pull the levers before V1, push them forward after V1,...can a cat be taught that?

I mean cat's have terrific reflexes, are very fast...and if all they have to do is watch the airspeed indicator for V1...maybe we could put a little mouse on the levers to keep her interested...corporate will love the low costs, they never get sick and they work for kibble.

:)

Right Way Up
20th May 2008, 10:19
Pilotbear,
I don't believe anyone has said that they would would always continue after V1. They have answered the original question with reference to engine fire and because it does not fit the "SSG model" they have been flamed for it.

BTW that post was aimed at SSG because of the uncalled rudeness to Pace, who left the arena in a composed way.

There is no doubt that there are situations that we think outside the box and use our best judgement at the time. That is why if their is sim time left at the end of a check we always try to throw something unusual at the crew.

Glen999
20th May 2008, 10:41
I cant see what the problem is aborting at v2. I fly out of stn. A little rudder straight onto the M11. Loads of room!!!!! No problem.:ok:

SR71
20th May 2008, 15:09
http://www.smartcockpit.com/pdf/flightops/aerodynamics/28

In principle, I agree with one V1 per T/O.

But in extremis (which is the point of the discussion isn't it?), with a V1 split of ~30kts....

Reminds me of that Eddie Izard sketch, "Cake or Death"...

http://www.youtube.com/watch?v=BNjcuZ-LiSY

Of course, what complicates things is Vr...

:ok:

ssg
20th May 2008, 16:23
Great link to the Boeing sit on min and max V1...I learned something!!!

Question.....if balanced field for the day is 5000ft on a ten thousand ft runway...could you calculate max V1 to just make the stopway on a rejected take off on that runway?

Right Way Up
20th May 2008, 16:30
SSG, on my aircraft you can select whichever V1 suits you. Our performance gives mean V1 for starters but we can also check (& use if need be) the min & max V1 to suit the situation.

mutt
20th May 2008, 17:30
could you calculate max V1 to just make the stopway on a rejected take off on that runway?The answer is a very definite MAYBE :)

Some aircraft its easy, others not so easy... all depends on the year of manufacture and the available software.

Mutt

Pugilistic Animus
20th May 2008, 17:31
Ssg--V1 is advisory-if the aircraft is uncontrollable then we'd all abort and take the 50/50 chance of dying common sense but in 99.999% of cases no--simple--that's why you have to love this game you alway have a chance to die!!!oh well better than dying on the ground-I guess:\

ssg
20th May 2008, 18:11
I have to admit that going to the Boeing link opened up my eyes..see my post on Flex ops.. Infact I invented a new V speed...I'm not kidding....:)

I don't think a post V1 abort wouldn't be so iffy with 7000 ft of runway left, a 1000 ft stopway, and miles of Iowa cornfield beyond...

galaxy flyer
20th May 2008, 18:20
Stealing my post a few pages back on refusal speed. If you don't recognize the term, I refer you to ground school. I will agree with the idea of stopping in the instance when V1 and Vr are "split" IF you know you can stop in the TODA and have the brake energy available. However, few civil planes have refusal speed charts or, for that matter, any relevant performance charts. In my old C-5 engineers computed about 50 entries in the take-off data sheet, including Vmca, Vmcg, take-off ground run (all 4 running) gradients, refusal speed, brake energy, climb capability on 4, 3, and 2 engines. A bit anal,but if you knew performance, good stuff. You cannot eyeball, in high performance airplanes, the take-off. The Force is with Luke, not you.

Would I abort after V1, yes, if the plane was uncontrollable (flight control problem) or suffered an extreme failure, say an engine explosion. If an engine fire lite came on as I went thru V1 and accelerating-NO. We're not trained that way, it is not briefed that way and the briefing is where critical decisions are made, not thundering down the runway making it up as one goes along.

For example, an old friend had a severe tire failure taking out most a bogey on a 707, after V1 and airplane stopped accelerating, stuck short of Vr. All went for brief swim in SFO bay. Two different friends have taken different C-5s airborne after bird strikes during rotation, one with 200,000 pounds of Class A explosives on-board). Both came around and landed under control with no damage. Aborts would have certainly overrun the available runway, the take-offs were that close and they lost one engine and significant thrust on the one other. A CO DC-10 did something similar in EWR and landed.

If you want a better idea, consider this: review the data available, using a runway analysis, determine the heaviest weight acceptable for the runway, IF the V1 for that weight equals or exceeds Vr for the planned take-off weight; set V1 equal to Vr. Yes, you have "unbalanced" the field length, not operating IAW with the training and FAA certification, and the insurers might disown you, but I'm guessing it will at least provide a logical justification for your operation. A few giggles, too.

At an airline I worked for, SSG, your mode of work was called, "in business for yourself".

PS: if you dare bring up the recent C-5 accident, the response is: THEY OPERATED LIKE YOU WANT TO--Unbriefed, uncoordinated, and poor technique under stress. The plane was perfectly flyable, IF they flew as trained by the book.

Mutt: I agree-few civil planes have the charts available for what is needed.

Chris Scott
20th May 2008, 18:42
Quote of ssg’s original scenario:
Assume you have 5000 ft extra runway past your balanced field length, your light, cool weather, everything is in your favor...you accelerate past V1 twards V2, and you get an engine fire...
Would you fly it off the ground or try to stop it?


Not sure if you’re a pilot, ssg, but you certainly made us all examine our principles and understanding of take-off performance. No bad thing. But there are at least two factors in your scenario that you seem to have overlooked.
1) Once VR has been called and rotation initiated, there is a major handling issue, as others have commented. [Granted V1 can be 30kts below VR.]
2) Bringing the aircraft safely to a halt on the runway with an engine fire is not necessarily non-fatal. If an engine fire occurs before V1, we must also assume thrust failure; so performance theory suggests continuing is not normally an option (unless someone wants to propose that on another thread). In that case we must settle for extinguishing the fire at a standstill − backed up by the fire service. Think of the B737 at Manchester, when a light crosswind blew the flames into the fuselage. After V1, even assuming the crew has a choice, taking the fire into the air [U]may be the safer way of handling the fire. Trouble is, there are engine fires and engine fires. Perhaps other Posters will comment?

The scenario you have chosen is predictable at the planning stage. So the decision can be made then, by choosing V1 = VR (but NOT V2). When there is so much surplus runway, a big range of possible V1s is available (between BOAC’s Vgo and Vstop); provided your company’s performance manual or computer is up to the job… Having said that, you may decide to choose a low V1 if departing an airfield with no engineering support, for example, in a 4-engine aeroplane.

Once a V1 has been briefed, there has to be a very extreme failure to justify flouting it. The above performance calculation is always based on the failure of ONE engine, as in your scenario. A more difficult case would be the failure of more than one (before VR). Amending your scenario to the recognised fire and/or failure of 2 engines on a light DC10 before VR, I think most of us would hope to make the decision to close the throttles. In a 4-engine jet, it's not so clear-cut (we used to practise it in the VC10 simulator, but the second one didn’t quit until we had rotated).

galaxy flyer
20th May 2008, 19:55
Chris: Hope "low" V1 is referenced to Vmcg.

One thought not brought to light. I am taking off between V1 and Vr, experience an engine failure/fire-unknown immediately is the loss of Sys 2 hydraulic power due to damage. Now, in my current steed, I'm down to 50% brakes-big loss of stopping power. If it were Sys 3, I'd have 50% brakes and no steering (yes, differential brakes, but further degrades stopping). Heavy transports frequently have lots of other system problems that would best be defined, handled and planned for airborne. Once airborne, the emergency landing will be accompanied by CFR, flight attendants will be ready for an evacuation, all aircraft problems will have been addressed. The approach can be planned so the crew/ATC is ready. I just believe the airplane is safer airborne unless it cannot get there. SSG-as opposed to the Citation (I have about 2800 hours in them) most transports, even large corporate jets, just do not always operate with oodles of extra runway. I have done plenty of take-offs in the GLEX at heavier weights where we didn't 3000 feet extra. And we use APG perf calculations on every take-off. Hell, on the Kennedy Skid Strip or Edwards AFB, I'd do lots of things with an engine failure. EDW is 13,000 long by 300 wide and goes into Muroc Lake Bed.

ssg
20th May 2008, 20:02
I think we can all agree that taking off from a 5000 ft field in a 737, balanced field is 5000 ft...20000 hour trend monitored engines, burning lake of lava at the end.... Is a little different then a Citation on a 12000 ft field, balanced field is 3000 ft, Iowa cornfields for miles., and new engines with 100 hours on them....

The later shows that the pilot has more discretion because he has more time, more options...To purposely take away those options by choosing a shorter runway, using Flex, adding weight...adds risk...I didn't say dangerous, I said risk...

I beleive that 'Pilot Discretion' is a problem for many in here...they want the pilot to have the numbers, the facts...not just look at the airspeed and runway remaining and make a call..the more they keep him from making a decision and just going to the checklist, they feel the flight will be less prone to a screwup.....I can understand that...

But stories abound of pilots that made quick descisions that saved lives that weren't on the checklist or calculated ahead of time, and we have seen the opposite as well...if anyone in here can brief for all possible scenarios, my hat's off to you...

History judges hard the ignorant...and luck favors the prepared...

Seems we are always finding a way to crash a plane who's problem wasn't on the checklist or the checklist was wrong when you encountered it...but we move forward by the ensuing discussion and learn from our mistakes...

Personaly discussing these scenarios and hashing them out ahead of time, looking at all the angles is better then waiting for another accident then trying to figure out what went wrong and adding another line on the checklist.

I have commented sadly to students, that someone had to die for every line on a checklist...and the checklists keep getting longer.....

They get longer because many times we encounter some form of ignorance, something that everyone overlooked, or outmoded concepts and training that needed to change... but again, a plane had to crash to uncover that hidden truth.

I feel these forums are a better way to uncover that truth....

FE Hoppy
20th May 2008, 20:23
rubbish!

having witnessed at close quarters the development and certification of a QRH for a new type before it's entry into service I can categorically state that no one died during the whole process. Nor have they died in the revisions of said QRH.

God help your students!

Pugilistic Animus
20th May 2008, 20:55
Ssg, could you comment as Mutt has brought up on the 15' wet screen height as well the four[I think] different possible certification scenarios and how they would work against your pax too----? compare and contrast :}

Also explain to me what are the basics of the segmented takeoff profile?-because a 4000'/min segmented climb oei at V2 wow:hmm:


although you've got us going man---:ooh:

PA

SNS3Guppy
20th May 2008, 21:12
PA,

Some light jets can still climb like a ruptured duck on one during second segment on up, or a single engine missed approach.

I still remember my right seat checkride in the Sabreliner 60, coming from older radial four engine equipment. I was very impressed with the performance. When I was given a missed approach off an ILS on one engine, I began pulling the power back on the good engine. The examiner had a fit and asked why. I had too much performance and only had three thousand feet to climb to the missed approach hold. It's a matter of perspective somewhat, there. He thought we had hardly any performance left, I thought we had too much.

A 20 series Learjet will hold 6,000 fpm in the climb easily enough, and the initial climb can exceed 12,000 fpm when light. It can hold several thousand fpm up through about FL290 or so. The cost, of course, is that you can actually see the fuel gauge move...:E

---(that's on two engines, not one)

Pugilistic Animus
20th May 2008, 21:24
SNS3Guppy

I think that the LEAR 20 series are not turbojets they're space rockets---or wannabe F4's:}---although I can tell you [as you know] they have taught some of the bigger jets how to really get upset though...I'll forever miss that baby though:(

PK-KAR
20th May 2008, 21:50
Question.....if balanced field for the day is 5000ft on a ten thousand ft runway...could you calculate max V1 to just make the stopway on a rejected take off on that runway?
Did anyone say you can't? As long as the V1 is below Vmbe and V1stop and Vr.
But then if you want to abort after Vr... that's a different story... I'd do it if I can't even reach V2 and decelerating if I still got the fence in front of me. If the fence is behind... well, pray...

Multiple engine failure etc? Well, if you are sure you cannot attain safe flight (for a safe return), just stop and pray you won't hit the petrol station on the other side of the fence (even if there is an extra 5000ft clearway after the 5000ft runway remaining).

The later shows that the pilot has more discretion because he has more time, more options...To purposely take away those options by choosing a shorter runway, using Flex, adding weight...adds risk...I didn't say dangerous, I said risk...
Flex is dangerous? *bangs head on table*
Let's put it this way, estimated value of risk from FLX / estimated value of savings from FLX. As long as your take off performance is legal, and your climb numbers are OK, if that equation yields an answer of <1, then FLEX is the way. If >1, well, the insurers will surely have a word with management.

It won't add another line the checklist...

PK-KAR

ssg
20th May 2008, 21:55
I understand the argument.. I hear 'legal' numbers and 'ok' climb...so Fly it to the fence to save some money on overhauls, even if you have to push balanced field into the overrun?

SNS3Guppy
20th May 2008, 22:03
I think that the LEAR 20 series are not turbojets they're space rockets---or wannabe F4's---although I can tell you [as you know] they have taught some of the bigger jets how to really get upset though...I'll forever miss that baby though


The Lear 24 is the only aircraft I flew in which I declared minimum fuel while taxiing :p.

Stuck in the lineup at Phoenix on a very hot summer day, 45 minutes into the wait, the reserve was gone and the air conditioning was non-existant. I asked the controller how long, he gave a mystical response about time and space and birthdays to come, and we declared minimum fuel. He asked if we were kidding, and we told him, no, we needed to taxi clear and go back to the FBO for fuel.

One of my reserve fuel tanks today holds nearly as much as the whole airplane did then...but it still kills us to hold short today for very long when we only allot 3,000 gallons for the taxi...some things never change.

I think that translates somewhat to this thread; it's different scales for different sizes of airplane, but the principles remain true...including those for V1.

Several posters here have thrown out some outlandish concepts regarding locked flight controls and so forth, and then asked the utterly ridiculous question as to whether one will continue the flight or not. Clearly when flight is not at all possible one will not...that shouldn't even need to be dignified by discussion...but where the airplane will fly and is able, there's just no good reasont to stay on the ground. Even in a Lear. With a drogue chute...

Of course, in a citation, where the biggest threat is experiencing bird strikes from behind...

Pace
20th May 2008, 22:08
>Also explain to me what are the basics of the segmented takeoff profile?-because a 4000'/min segmented climb oei at V2 wow<

As this thread has taken on a new lease of life and everyone appears to be changing sides I would like to know which Citation will climb at 4000 feet per minute at V2 unless it has literally no fuel and no pax ?

Pace

Diesel8
20th May 2008, 22:12
"if you got a flap asymmetry warning, an un-commanded slat retraction, a trim runaway, an obvious control jam or hard-over, a double engine flame out, (if you only had two for the less astute among you) after V1 you would not even consider aborting the take off because you had said so???"

If the space shuttle, operating on UHF Freq, lands 2000 feet in fron of you, but you have an engine over temp at Vr, are you still going to attempt to stop? What if it is a UFO?

Isn't this getting a bit esoteric? If you have a loss of both engine, it will be a very short flight, whether one rotates or not. All the rest of your examples are just about the same, the a/c isn't going to fly, well again, at least not very far. However, I am at loss to any of your examples ever having happened, doesn't mean they can't, but it is highly unlikely, bordering on impossible. I mean really, dual engine flameout on the runway???

ssg
20th May 2008, 22:12
No one said anything about v2 or single engine...Citation Vs, Ultras and Encores can do 4000 ft/m...for while

Pace
20th May 2008, 22:23
Dieasel 8

Probably the most sensible thing said. Dual flameout forget V1 VR and the rest because you are not going anywhere fast.

Control failure the same. Massive engine fire or airframe fire and I am taking my chances earthwise, If need be at the end of the runway I will do a formula 1 turn up a taxiway :-) to extend my ground run.

The rest sort it out in the air.

Pace

PK-KAR
20th May 2008, 22:33
I think that the LEAR 20 series are not turbojets they're space rockets---or wannabe F4's
Isn't it an oversized fighter with fighter wings and a plush cabin instead of a bomb bay? :E

so Fly it to the fence to save some money on overhauls, even if you have to push balanced field into the overrun?
if the company wants to go to the overrun as part of the stop, so be it, I'd probably just move companies. Flex it as far as the stop goes to just short of the overrun and the climb numbers are OK is fine by me. If the company wants to loose the tyres being sunk in a soft overrun, it's their choice. The insurers will have a nice chat with the management.

But when that's the V1 chosen, definitely no abort past V1 unless the conditions dictate it's better to stop and pray I make it before the petrol station on the other side of the fence.

Basically aborting past V1 as per the majority of your posts and flex is the same in that you're making the decision with less stopping distance available.

If you've been preaching you'd stop past V1, I don't see why you'd look down at flex t/o... unless, you want to abort past V1 so much that you'd never flex t/o because you know U'd be in deep doo-doo whenever you make a stop or go decision past V1high... :=

Have a read at that link again, with V1low, feel free to be stop minded, with V1high, be go minded. Your choice, your life... we won't laugh. If your stop minded with V1high (which I'm sure U're not), then we won't laugh, we'd just shake our heads. http://www.indoflyer.net/forum/upfiles/smiley/joget.gif

If you're nitpicking as to which is safer, and your workplace has a V1 policy you're not comfortable with, just move somewhere else that can give you the comfort (dunno and dun really care which companies go for V1bal, V1low or V1high, take yer pick), and accept the fact that some others have a different V1 policy to what you want that's still legal (and safe ..

SR71
20th May 2008, 22:52
Several posters here have thrown out some outlandish concepts regarding locked flight controls and so forth, and then asked the utterly ridiculous question as to whether one will continue the flight or not. Clearly when flight is not at all possible one will not...that shouldn't even need to be dignified by discussion...but where the airplane will fly and is able, there's just no good reasont to stay on the ground. Even in a Lear. With a drogue chute...

With great respect to the crew of AA191, I bet they were pretty unimpressed with the outlandish event which led to them losing No 1...after all, initially, the indications probably just looked like any other engine failure...

Diesel8,

Un-commanded slat retraction - 1979, AA191

Obvious control jam, hard-over - 2001, LH A320 Cross-wired Sidestick

Double engine failure - 2001, S360 departure from EDI

Say again, what you think is impossible?

The point is, that there may come a time, when near, at, or above V1 you might be called upon to make a decision about whether or not your aircraft is able to fly...

...there's just no good reason to stay on the ground...

I figure the fact I don't have feathers is a pretty good reason...

The problem is, that regardless of what decision you make at that point, if the outcome is successful its self-justifying...but whether or not there was a better outcome, will always be debatable. Plus, you'd be a brave pilot to admit as much, esepcially if there were fatalaties...

When operating at the edge of the envelope, I prefer not to extrapolate based on the norm...that is bad practise in any mathematician's book...

Hoping it never happens to me....

:ok:

ssg
20th May 2008, 23:18
+1....well said / There are alot of pilots in here living a world where things don't go wrong, just pull the levers before V1, push them up after. I take solace in the fact that maybe these posters are retired, don't fly, unemployed, or at the least FOs where they are not allowed to make a decision...

lomapaseo
21st May 2008, 00:21
+1....well said / There are a lot of pilots in here living a world where things don't go wrong, just pull the levers before V1, push them up after. I take solace in the fact that maybe these posters are retired, don't fly, unemployed, or at the least FOs where they are not allowed to make a decision...

Of course you and most others here have a damn good idea of how to make rational decisions of whether to go or not.

The problem is the time base that you are constrained to rationlize such a decision and so little training or experience in creating rational thoughts outside the box in this time period.

So I'll rather trust my life with pilots that think inside the box (of their training), for that has been proven statistically safe.

ssg
21st May 2008, 00:34
Your absolutely right..we can monday morning quarterback for hours all these scenarios when in real life the decisions have to be made quck..

But I will throw this at you...if they can't make the right decision in front of thier computer, how will they do it at 120kts having just clipped a fuel truck post v1?

Bucket
21st May 2008, 00:55
With a thread this long I looked at the first page and the last.

There really is no point in debating this apart from certain acedemic aspects to the process which can be interesting since it throws up a couple of curved balls.

There is no data in the FM for braking distances beyond V1. And for good reason. If you decided to flip that particular coin then you become your own test pilot and I'm not too sure the rest of the crew will thank you for it. Even if the decision to remain on terra firma after V1 is taken and gotten away with due to extreme circumstances the post flight euphoria will diminish when the investigation reveals that you were happy to keep the problem earth bound. No protection in a court of law for that. Then you are on your own; a lonely place to be.


:=

ssg
21st May 2008, 01:05
Gee Whiz can't anyone in here look at some pavement and get a decent idea if they have enough to stop? We do it every day in cars...what's the diff?

Diesel8
21st May 2008, 01:18
"Un-commanded slat retraction - 1979, AA191

Obvious control jam, hard-over - 2001, LH A320 Cross-wired Sidestick

Double engine failure - 2001, S360 departure from EDI"

And in which ones of those were the a/c still on the ground past V1 with the ability to safely stop?

Cannot speculate on 191, although the uncommanded slat retraction was a we all know, due to the fact that the engine seperated from the a/c. Had it just been an engine failure, little doubt they would have survived. Had they stopped, for a "mere" engine failure past V1, it is not known, that the a/c would have stopped on the remaining rwy, it may well have plowed into houses, broken up and burst into flames. The report would have certainly faulted the crew for that, afte all, that would not be SOP nor the manufacturers recommendation.

In this article, you will notice, that the engine loss/slat retraction was deemed surviveable, after having re run the scenario in the sim, however, certainly we cannot blame the pilots on AA191, rest their souls, for the outcome. http://en.wikipedia.org/wiki/American_Airlines_Flight_191

LH was not a control jam, the controls moved freely, the CA sidestick was miswired, the F/O stick was working properly. They found out when the a/c was airborne, that is when the CA used roll input. He would not have been aware prior to V1, that is unless they had noticed the anomaly during the control check at taxi. Of course, in that case they never would have taken off. Certainly you are not advocating the LH pilots should have tried to land on the same rwy after having been airborne, with a stick malfunction to boot. That surely would have led to an overrun or worse, a crash. Interestingly enough, Airbus FBW do have a procedure for frozen or malfunctioning sidestick and no one was harmed in the incident.

The SD360 was at 1200 feet when they experienced trouble, a couple of minutes removed from V1, is that example even pertinent? Why not mention the SAS MD-80 out of Stockholm, they had dual engine failure a minute or two removed from V1. Maybe they Gimli glider should have aborted at V1 plus 20, then they never would have suffered dual engine failure in cruise.

None of your examples appear to offer much that is relevant, nor anything that supports the argument of stopping past V1. In two of the cases, the a/c was already airborne, with no indications of malfunctions prior to and in the case of AA, the crew had no indications of anything other than an engine failure. The AA crew at the time, made the right choice based upon what hey knew, since they couldn't possible have known the engine was torn off and that the slats would retract.

Statistic show, that the safest course of action, past V1, is to continue the takeoff. It has been proven time and time again. It is the recommendation of all FAR 25 manufacturers, all airlines, all training academies etc, etc.

Is it possible to come up with situations where it would not be the prudent course of action, yes it is. Dual engine failure on the ground, an aircraft that will not rotate, loss of an entire wing, etc. However, do any of those happen on such a recurrent basis, that it should be considered normal, besides, under such scenarios, is there even a choice?

ssg
21st May 2008, 01:32
Is there any emergency when taking off that you would consider normal.?

Funny, the latest accidents I see are blown tires, plane doesn't accelerate, someone horses it off the runway then crashes...

gotta go, gotta go....

Pugilistic Animus
21st May 2008, 01:37
True Ssg there's been tons of bloodshed in aviation to make it safe--and yet we insist on recreating the original TO and LDG accidents--for historical and educational purposes I suspect :*

Diesel8
21st May 2008, 01:43
"Is there any emergency when taking off that you would consider normal.?"

Nope, but then again, losing an engine, considering the excellent training we get now a days, could probably be considered more of a non routine. A blown tire shouldn't cause much grief in the front office either. Having been through both, cannot say they were much of an event.

Here is a great example of some well executed airmanship:

http://www.youtube.com/watch?v=uYNpB-8_BSo

Should they have tried to stop?

This one was an RTO at supposedly 12kts above V1:

http://aviation-safety.net/database/record.php?id=20060607-0

http://www.youtube.com/watch?v=wj8UPEfO1Oo&feature=related

Chris Scott
21st May 2008, 01:44
galaxy flyer:
Yes, V “go” must take Vmcg[1] into account. On 4-engine airplanes configured like the B707, that’s quite limiting to the range of V1s when you are light. But on those (rare) beasts like the VC10, Comet/Nimrod (and maybe Concorde/B1), with less asymmetry, Vmcg can be quite low.
Must admit I’d forgotten the difficulty of obtaining a range of V1s with present-day instant tables or computer programmes. Good idea of yours to use the RTOW case to find the top figure, but wouldn’t know how to find the bottom one. On the VC10, we used to do it all from basic principles, taking about 10 minutes (including a Flex calculation).
Surprised to hear of 50% braking in some single-failure circumstances on your present type.

Pace and Diesel8:
Yes, a double engine failure before VR sounds unlikely on a 3 or 4-eng aeroplane, so why did we consider it unofficially on the VC10? Because the engines are behind the landing gear and mounted in pairs, like the Comet/Nimrod, Jetstar and Concorde (not to mention the B1 and B52). As far as conventional aeroplanes are concerned, there was the El Al B747F that was unlucky enough to throw a blade from one engine into the other over Amsterdam.
By the way, the VC10 can get airborne on 2 quite nicely even at medium-to-high weights, particularly at sea-level. [After all, it’s only like a twin losing one, although the performance regs don’t have to cater for it.] Not so the under-powered Seven-oh. And I seem to remember the 707-320 with JT3D-3Bs had a Vmca[2] of 147kts, so it could not manage it even at low weights, if the failures were on the same side.

ssg:
I know that you are, to some extent, playing Devil’s advocate. But in relation to Flex, don’t forget that TOGA is still available as a bonus (though not assumed in the calculation). De-Rate, of course, is another matter.

Having “taken the shilling”, I advocate sticking to SOPs to the letter; but not all scenarios can have an SOP. The trick that we all hope we will never have to perform is that of recognising that there is no applicable SOP, no time for “DODAR”, and still making a good decision.

Diesel8
21st May 2008, 01:49
So Chris, in the VC10, if you are at VR and both donkeys on one side decides it is time to eat hay, are you stopping?

Pugilistic Animus
21st May 2008, 02:04
Chris Scott has written:
Having “taken the shilling”, I advocate sticking to SOPs to the letter; but not all scenarios can have an SOP. The trick that we all hope we will never have to perform is that of recognising that there is no applicable SOP, no time for “DODAR”, and still making a good decision.

Now that is a true/ well conceived / learned and balanced statement--:D

Ssg you should heed his words brother:ok:

galaxy flyer
21st May 2008, 02:07
Chris

What I said was that if the engine failure were accompanied by loss of fluid in one of the two systems that power the brakes, I would have 50% of brakes. The brakes on Challenger/Global are divided inboard and outboard powered by system 3 and 2, respectively. Yes, it is a compounding emergency, but loss of fluid quantity could be caused by uncontained hot bits from an engine disintegration. The brakes normally have two pumps powering them-AC and Engine-driven, so it is a remote possibility. Once the fluid is gone, no power for those systems. The C-5 was similar where loss of system fluid required switching to alternate brakes-just a switch actuation by the Co-pilot, but easily missed in the heat of a overspeed abort. But you did then have all the brakes.

My point was it is better to address these issues airborne. I presently have plenty of brakes for stopping with a 50% loss, if it is planned for.

BTW, the C-5 has a low Vmcg of around 80 knots, dry, no crosswind. We computed corrections for both runway condition and crosswind. I'd like to think the low Vmcg was due to having four very powerful APUs as engines.

Diesel8
21st May 2008, 02:10
"Now that is a true/ well conceived / learned and balanced statement--"

Agree indeed!

ssg
21st May 2008, 02:22
Having “taken the shilling”,

Loud and clear...families to feed and all that...a faustian choice....who knows one of these days I might be up there planning my egress into the stop way...rolling down the runway, less power then available, yanking it up at VR, over the fence...rolling left because of the tanker I just clipped...before I go in...I joke to the FO....'well atleast were getting paid'

It's no different then corporate...to be honest...the owners would have me working main st for $5 a pop if they could get away with it...hang on to your unions boys....

P. Animas...don't worry I'm a whore just like everyone else but I have limits...

Pugilistic Animus
21st May 2008, 02:26
SSG that's the spirit of the business:D You've been Schooled!!:}


I'm gonna take my meds now:)

CAVU!

ssg
21st May 2008, 03:26
A jetliner was forced to pull out of a landing at Sao Paulo's Congonhas airport yesterday as new footage emerged of the Airbus 320 that crashed earlier in the week, showing the aircraft travelling along the runway at more than three times the usual landing speed.

Security video footage appeared to show the aircraft hurtling down the runway in just three seconds. Video footage of a similar aircraft landing just minutes beforehand showed the plane taking more than 10 seconds to complete the length of the 1,900m runaway.

More than 180 people were killed when the flight careered off the runway and burst into flames after hitting buildings at the northern end of the airport.

Pugilistic Animus
21st May 2008, 04:15
BTW, the C-5 has a low Vmcg of around 80 knots, dry, no crosswind. We computed corrections for both runway condition and crosswind. I'd like to think the low Vmcg was due to having four very powerful APUs as engines.

Wow GF---you USAF folks really keet your performance airtight!!!!

and a VMCG of 80 KIAS--or is it KEAS for you?---would never have guessed!

galaxy flyer
21st May 2008, 04:36
Mulitple entries in the AF 4098 Take-off worksheet-about 50, I'd guess. A good engineer could do one in 20 minutes, if there wasn't a difficult climb gradient problem. We always had Vmca2, refusal speed on the pilot's card. Normally, refusal and rotate were computed and then compared to Vmbe and Vcefs (critical engine failure) and the limiting one became Vgo (V1). On take-off the PM just called "GO" signally stopping was no longer an option. Did a near GO stop at Sigonella once, just made it. Then "rotate", of course. Gust increment was added to Rotate and V2. It was a very marginally powered aircraft, or too heavy, if you prefer. Above 712,000, its originally gross weight, additions were notable in performance. OEI climb gradient could be as low as 2.3% with no obstacles. Surprising amount of this stuff stuck, but I instructed to pilots. Who were not impressed!

KIAS, not EAS, but Old Smokey smiles at you mentioning it. :D

SNS3Guppy
21st May 2008, 04:55
KIAS, not EAS,


Oh, heaven forbid...:p

SR71
21st May 2008, 10:07
Diesel8,

I wasn't using those examples as strictly relevant to the case initially proposed in the thread, but rather to demonstrate how what one might consider nigh on impossible, has probably already happened to someone somewhere....

Who would have thought a 777 could have a "double engine failure" on short finals over London until a few months ago (not strictly true, but to all intents and purposes, that is what happened)?

I have to say that everyday I get airborne I'm cognizant of the fact that my flight director scheduling, should I have an engine failure, is designed with AA191's experience in mind. Its a sobering thought.

We all know what the statistics say (although I have to say they won't be much comfort to me when the proverbial hits the fan), we've all read The Pilot Guide to Takeoff Safety...

I'll bow out with a quote from that document:

There is more to the Go/No-Go decision than "Stop prior to V1" and "Go after V1".

Safe flying.

:)

mutt
21st May 2008, 11:40
No one said anything about v2 or single engine...Citation Vs, Ultras and Encores can do 4000 ft/m...for while Actually, if i remember correctly, the statement was from you in repsonse to my question about how you ensured your obstacle clearance during takeoff and climbout.

So now that you are back peddling, please answer the question, how do you ensure your obstacle clearance following an engine failure?

Mutt

Pace
21st May 2008, 12:07
So now that you are back peddling, please answer the question, how do you ensure your obstacle clearance following an engine failure?

Mutt

A few years ago I was involved with a forum for Microsoft Flight Simulator. I did some development work with addon companies, wrote reviews and was fairly active in their forums.

The problem with all these forums is that they are open to a lot of people who hide behind a cloak and claim to be something they are not.

There was one guy in particular who challenged the real world pilots on those forums and fair enough some of the stuff he came up with was quite convincing.

But in other ways his approach was very purile and he made major blunders.
We discovered that this experienced so called pilot was infact a 12 year old kid who was merrily googling his answers on the internet and somehow getting a kick by playing out his act. He fooled a lot of airline and corporate pilots for some time.

Pace

PK-KAR
21st May 2008, 15:29
A jetliner was forced to pull out of a landing at Sao Paulo's Congonhas airport yesterday as new footage emerged of the Airbus 320 that crashed earlier in the week, showing the aircraft travelling along the runway at more than three times the usual landing speed...

http://www.indoflyer.net/forum/upfiles/smiley/oot.gif
This accident was caused by not putting both thrust levers to idle then only reversing the idled engine thus resulting in 1 engine giving positive thrust, the other in reverse, and no spoilers deployed.

It's got nothing to do with aborting past V1... off topic!
What are you trying to pull here? *our legs?* :E

mutt
21st May 2008, 17:08
and I am still waiting for those engine overhaul numbers and cost Do you really think that I'm going to release information that my company considers "commercially sensitive"?

And I dont believe that you did answer the question about obstacles... humor me... quote me the page from the FMS guide where it says that the takeoff path can be calculated with an engine out, and also tell me who is your obstacle data provider......

Mutt

PK-KAR
21st May 2008, 18:36
Since SSG is so desperate for the numbers, I'll give him one a from a now defunct operator... got it from the guy who had worked there... accuracy not guaranteed. I can't give the exact numbers for obvious reasons.

Numbers for the 733/4/5, average hour to cycle ratio 1h10m, 10 cycles a day average. Destinations are all <2500m runway (mostly <100ft elev, ISA+15C) except for 5 airports with 3000m - 3600m runways.

Derate take off & derate climb policy = about 50USD per cycle. at 10 cycles a day, equivalent to 100k - 150k USD per year.
Derate take off only would save about 30USD per cycle (less fuel and engine wear, whereas the derated climb expends just a little bit more fuel, but significantly reduces engine wear).

trickle451
21st May 2008, 20:17
Curious...what is the cost of the engine they were using and the total cycles allowed...engine cost divided by cycles = cost per cycle.

Chris Scott
22nd May 2008, 00:44
Quote from Diesel 8:
So Chris, in the VC10, if you are at VR and both donkeys on one side decides it is time to eat hay, are you stopping?
[Unquote]

The short (and honest) answer is that I don’t know. The slippery one is that you haven’t supplied me with enough data! [You should ask one of the RAF guys; I’m over 30 years out of date.] Think I should admit first that anything offered here is, by definition, merely an armchair decision...

Let’s assume that ssg’s 5000ft-excess of Balanced Field is leaving us with about 5500ft of runway remaining at Vr.

At sea-level, if not already rotated, I think I’d go, as she should fly okay − even at MTOW. But with that amount of pavement remaining, she should also be able to stop. If rotated significantly, I’d go.

At Nairobi (5327ft amsl, if memory serves), both options are less attractive. TAS/GS would be higher; thrust lower. We’ve already used 8000ft of the 13500ft runway, so we are pretty heavy. Initial climb would be marginal. The gear will have to stay down initially, because of the extra drag of opening the gear doors. Think I’d stop, and almost certainly overrun the runway. If already rotated, I’d have to go, and fuel dumping would start asap.

On the B707-320 with 2 out on the same side, the decision is simple: stop in all cases; because of lack of thrust when heavy, and the high Vmca[2] when light. Cannot comment on the various types of DC-8s, B747s and A340s; never flew them.

trickle451
22nd May 2008, 01:01
Sounds like one of those..

.'you have to be there..see what the planes actualy doing...make a decision'

john_tullamarine
22nd May 2008, 04:47
This has been a spirited thread.

Procedural points to keep in mind ..

(a) several folk have complained about some of ssg's posts. Be aware that I am following along behind and I alter/delete posts which I think are a bit out of line .. not just ssg's .. any ...

(b) so long as the posts are not too far out of order and the subject remains reasonably on flying matters the thread can remain here to stir up objective passions

(c) if individuals get to the stage where they feel that the thread is going in circles or whatever, there always remains the option to ignore it .. when enough lose interest it will, like near all threads ... sink into the abyss.

As a moderator, it is not my personal task to be the arbiter of what content should or should not be in threads .. only that they reasonably follow PPRuNe requirements.

The only "rule" we have here is that outright rudeness etc., will be modified or deleted as we consider appropriate

discountinvestigator
22nd May 2008, 14:49
Just a few thoughts:

1. I worked on a 767 which RTOed after no engine failure but failed to get airborne after Vr and sitting on the tail skid. Good thing they went for the RTO option as the airline calculated the various V speeds and put the wrong mass in for the take-off. (I seem to remember it was ZFW they put in when it was going off on a 10 hour jaunt but the pilots did fly short sectors at low masses in it too).

2. A 747 where the incorrect flex power was set and failed to get airborne

3. Please remember that more airports have full length 300 metre runway end safety areas than used to and some have delethalised (eugh!) the run off areas (size dependent on runway length)

4. The DC-10 multiple tyre failure scenario was made much worse by the (then) tyre design standard (or should it have been tire?) which only required the other tyres to carry 1.5 times the rated load. With the DC10 beam deflections, the opposite corner used to carry 1.97 x load which then blew it. Then you were in deep trouble, made worse by the wheel rims fracturing and shattering with subsequent spreading of the bits around at high speed (to cut hydraulic lines and penetrate fuel tanks). Then you have nothing for the brakes to bite into as there were no tyres left. Also the DC10 would not reach Vr when this happened so you were in trouble. Oh, and the brake pack wear could be minimum on all wheels so that you did not have enough energy absorbtion available to stop in time. A change in tyre load standards, wheel rim design standards, brake pack wear requirements and trying to get the V1 as close to Vr as possible helped stop the DC10s from falling off the end of the runways as often as they used to.

5. Not sure if the locked wheel non-rotation when taking off on an icy runway scenario still exists that did for the odd DC8 on departure. The wheels slid without rotating and the subsequent extra drag stopped the aircraft from reaching Vr. I seem to remember it was Anchorage, it was full of US Marines or similar so the evacuation was relatively successful based on fit males all willing to listen to commands etc.

6. If you have to stop, think about flaps which are generating lift and consider (coffee break only time, not when it is happening) raising them. The spoilers should kill the lift but I am working on one with no spoiler deployment. You probably don't have time to even think about the action when doing it for real, but it is worth talking through!

7. Remember to press the brake pedals as if you life depends on it. It does. Many pilots used not to press them hard enough. NASA simulator studies (ok, old data here) showed lots of pilots at the 70% pressure level. I hope that this has been trained out in many cases now.

8. If you RTO off the end and the nosegear collapses, many big jets will lose the PA from the cockpit. Makes the evacuate call a bit difficult to hear.

I hope that you never have cause to find any of this falling into "useful practical advice" classifications in your worlds. Unfortunately, I do in mine on a daily basis.

VinRouge
22nd May 2008, 16:55
Doesnt JAR OPS assume engine failure at Vef, followed by a 2 second acceleration past V1 prior to executing and RTO, as part of accreditation?

Personally think that this is one of those areas where you on the day have to make the call, only however if you understand if its the wrong call and you have gone against SOP, you are going to get crucified.

FE Hoppy
22nd May 2008, 19:09
Remember that of the 97 overrun accidents recorded, 55% could have safely got airborne!

Saving about 200 lives!!

Angels 60
22nd May 2008, 19:22
There will always be an accidents where someone who should have flown, rejected, and there will always be accidents where people who should have rejected, flown.

I just wonder, if more people died trying to fly a bad aircraft then reject into the grass at the end.

The accident statistics tend to say 'go' given all the bad reject accidents, but if someone tallied up the deaths from either way, I suspect the deaths from skidding off the end, are much less then flying to the scene of the accident.

SNS3Guppy
22nd May 2008, 19:44
Angels 60, whereas you're the same poster who was recently banned as ssg and Trickle 451, now back under a different name, where are you headed with this?

When one continues the takeoff after V1, one doesn't fly to the scene of the accident, one flies to safety; that's the point of continuing after V1.

Same agenda for you, or do you intend to keep backpeddaling?

BusyB
22nd May 2008, 19:58
As I recall in the early 70's there was a Northeast Trident 1E that abandoned after V1 on RWY 28 in Bilbao. There was a large hill at the end of the RWY and in the Captains opinion the a/c had stopped accelerating (big split between V1 and Vr). The result was an excursion off the side of the RWY, one main gear collapsed and no-one hurt.

Initially the captain was held at fault until investigation complete when he was completely exonerated as it was found that deep puddles on the RWY which were not notified to the crew made it a contaminated RWY and the a/c was unlikely to have ever reached Vr.

With speed trend arrows that we now have I have on occasion seen the acceleration cease momentarily during a T/O and if this was substantially below V1 at Max Wt it would certainly make me think (usually more thrust is available).:ok:

FE Hoppy
22nd May 2008, 20:20
Look at the facts, read the statistics and then make your own mind up!

The aviation authorities all agree, the manufacturers all agree.

see what the FAA think (http://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf)

Angels 60
22nd May 2008, 21:40
BusyB...Probably took a stong will to go against his company SOPs, social pressure, and the chance to get called on the carpet. Sounds like common horse sense and good situational awareness won out that day.

galaxy flyer
22nd May 2008, 22:12
Fanatic-someone who won't change their mind and won't change the subject!

Chris: The VC-10 was one truly powered airplane if it could rotate and fly at SL with 2 out on a side. Vmca2 on the C-5 was fairly low, like the Vmcg, but flying off with 2 out would be hard to fathom except at very low weights, about 525,000 or less and favorable conditions. At that weight, Vmca2 would be close to V2.

lomapaseo
22nd May 2008, 22:59
Look at the facts, read the statistics and then make your own mind up!


That doesn't work on a discussion board.

Those that want to argue their points will always selectively select any facts that support it without regard to historical statistics. The belief being that if you accept their arguments that it will change the future statistics.

Pugilistic Animus
22nd May 2008, 23:28
Pilots who think
Discount ....+1 Today 11:55


It sounds like he was detailing improper handling of RTO's and ---you can throw the best SOPs at any one but---if you can't correctly compute performance---then how that the fault of anyone---yes, you can force yourself to RTO after V1---but that's mostly pilot error--forgetting gust locks improper use of performance chart an improper configuration with the warning out---no one ever said there's Never a reason to RTO --and certain freak events [the DC-10 has had it's bad days:(]---but it will most likely be YOUR fault---but what if there's a 200' drop at the DER? or a gas station a group of row houses?---excepting freak events you --GO!!! period----it would take some resolve to take that shaking aircraft into the air---that's why you need heart!!


split second decision have saved lives--such as when a United 767????---held off on rotation because of an incursion----or when the pilot forgot the gust lock on a Challenger 600??? and aborted at past Vr and flew into a building and they all lived---and sometimes Fate is a Hunter!!!!

for the most part in 99.99% of cases you GO!---the other .001 cases perhaps could have been avoided and a few:(

that's life---- that's flying---live with it--- die with it or get out!!!

nuff said

PA


and no I'm not back pedaling I've said basically the same thing earlier

airfoilmod
22nd May 2008, 23:44
The wording of the question invites misunderstanding. Would you abort? Well, Yes, for obvious reasons, discussed here. The question implies discretion on the part of the Pilot. V1 means go, (Fly). It is a pre-decided V speed, and by definition, Removes (most) Pilot Discretion. Some Pilots, for reasons of inexperience or lack of understanding of English, will argue that V1 doesn't do what an experienced Pilot knows that it Does. If you like, whisper to yourself at Vef "Mother May I ?", then Launch, immature Ego intact.

Airfoil

V1, that speed at which I will continue the Takeoff Roll in every instance except those in which I cannot Fly, in which case I won't.

"I cannot Fly" : that condition in which, in my belief, the A/C will not Fly (God I better be right), or, the A/C refuses to Fly, (much better).

PK-KAR
23rd May 2008, 08:02
Pardon my Trollfeeding lads, but someone's gotta do it! :E

There will always be an accidents where someone who should have flown, rejected, and there will always be accidents where people who should have rejected, flown.

Have a read at: http://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf

Interesting that Ssg would only use the accidents where continuing the flight leads to an accident and where aborting would lead to a successful outcome.

Nice that the FAA has said that in cases where one elects GO, an overwhelming majority of cases leads to a successful result, and does not get reported... so the reasoning that SSg use is... moot to say the least.

PK-KAR

Heli-phile
23rd May 2008, 08:56
V1 Is V1, if you cannot follow the rules dont play the game. You have to work in realtime not hindsight.:mad::ugh:

Heli-phile
23rd May 2008, 09:18
SSG you would be the worst nightmare on the flightdeck in an emergency.

Move over fast fingers freddie, we now have Second Guessing Git or put simply the SSG factor. The time to start being dynamic and using lateral thinking and problem solving is not at V1. :=

Angels 60
25th May 2008, 02:28
Yes I would...if the plane didn't accelerate to VR, massive control failure..missle hit the wing...anything that I knew would keep the plane from flying up in the air, I would take my chances in the overun.

VinRouge
26th May 2008, 10:30
wonder what happened here?

http://edition.cnn.com/2008/WORLD/europe/05/25/belgium.aircrash.ap/index.html?iref=mpstoryview

SNS3Guppy
26th May 2008, 10:51
Considering there is no useful information available at this time, and most parties involved in the upcoming investigation aren't even on scene yet, speculation is unprofessional, and inappropriate. One may rest assured that all the details will come out in good time.

Old Fella
26th May 2008, 13:36
Maybe ssg was flying the B747 and attempted to abort after V1. Very sorry, could not resist.

barit1
26th May 2008, 15:34
...if the plane didn't accelerate to VR, massive control failure..missle hit the wing...anything that I knew would keep the plane from flying up in the air...

Or this: (http://www.ntsb.gov/Events/2006/TeterboroNJ/Teterboro_IIC_Opening_presentation.pdf)

How often do catastrophic CG errors happen in airline ops?

Denti
26th May 2008, 15:45
Damn, they never even tried to calculate their CG? That is something that will never happen in airline ops. However, miscalculated CGs do happen, very rarely though. The Lufthansa 737 QC comes to mind where they loaded several tons of freight in supposedly empty containers putting the CG way out of the forward limit, still the thing flew, although they had to use stabtrim to fly it.

A real concern however is the use of generalized standard weights that are most probably too low.

OnePercenter
26th May 2008, 16:46
Emory flight out of Sacramento....cargo bins shifted..unflyable aircraft...I would imagine they shifted at rotation though, so the crew couldn't have caught it.There are million reasons why a plane won't fly, before or after V1, we have to be ready for it.

PK-KAR
27th May 2008, 17:40
Maybe ssg was flying the B747 and attempted to abort after V1. Very sorry, could not resist.
Interesting that you thought of the same thing... The moment I saw the photos, I thought... "Oh boy, SSG was so desperate to prove his point"... perhaps with derate too... :ugh:

Dufo
28th May 2008, 00:46
If this counts as abort after V1 :E
I have experienced aborted takeoff in L410 just after PNF selected gear up when the left engine lost power and autofeathering failed. I was PF and perhaps one second later cpt and I decided to retard power, consequently regaining control and landing straight ahead - everything worked out ok. Luckily the runway was long enough for three greens to light up again.
Couldn't sleep for a few days (flights were from 10pm to 6am) after that..

barit1
28th May 2008, 12:55
Ummm...

Seems you demonstrated you hadn't yet reached V1max.

:ok:

FE Hoppy
28th May 2008, 21:52
What Dufo did was NOT an aborted take off. He did a forced landing straight ahead.

The take off was well and truly over if his gear was up, in-fact so was the first segment of the take off climb.

Back to school for you ssg.

SNS3Guppy
28th May 2008, 23:31
The take off was well and truly over if his gear was up, in-fact so was the first segment of the take off climb.


If gear up, second segment of climb, actually.

Mach E Avelli
29th May 2008, 00:05
Barit1, if the runway is long enough and the aircraft is a STOL or nearly STOL type, or even a high performance type operating at a light weight 'V1 Max' for the situation described could be any speed that allowed it to stop by the far end. But then, in the interest of handling, tyre speeds etc Vr would happen before your 'V1 Max', so that opens up another can of worms and one which has never been addressed by certification.
My belief, of course, is that if it won't fly, I hope I recognise the fact in time to chuck it back on the ground. If it will fly, I will respect V1. It's the grey area between knowing and not knowing whether it will fly that is the problem. If seriously in doubt, on the ground is the better place to be, as long as you are not going to hit a bridge or brick wall or block of apartments on the over-run. Had the Concorde crew known what was unfolding, I bet they would have rejected even though they had passed V1. Sadly, they had no way of knowing just how bad it was.

Clandestino
29th May 2008, 00:59
Buffo was flying the turbolet. Turbolet is Czech-built, high-wing, STOL, unpresurrized twin turboprop. It can be flown at MTOW from 800m grass strip. Ljubljana has 3000m of asphalt runway. Not quite a limiting runway, eh? What if it were ATR flying from 1200m rwy? Hitting the cornfields at 100kt is not particularly survivable.

If you abort above V1 in runway limited situation, rule of the thumb is that speed off the end of the runway is speed above V1 when the abort is initiated multiplied by 10 (source: DLH FCM, chapt 7). And that is with proper abort technique (full spoilers, full brakes and idle thrust). Therefore abort at mere 5 kts above V1 gives you 50 kts as you crush the red lights.

So would I abort about V1 in a transport category airplane? If I have a choice - no. Not just because my SOP tells me so but because it is waaay too :mad: dangerous. Half mass multiplied by the velocity squared can really bite you. And ground behind runway may have too low PCN for your ACN.