Rejecting A Takeoff After V1…why Does It (still) Happen?

[decurion]

Aborts at a high speed (above V1) are rare. However when they occur the outcome can be a serious accident. The following paper discusses why this still occurs despite efforts from the industry to stop this.

http://www.nlr-atsi.nl/eCache/ATS/15/694.pdf

The analysis in the paper showed that there is still plenty of room to improve takeoff safety and reduce the number of unwarranted rejected takeoffs above V1. What do pilots and safety specialists think about this? All views are welcome but please read the paper first:)!

[Maurice Chavez]

I believe there has to be more emphasis during simulator training, to help understand the "unsafe to fly" condition. Simulator training these days concentrate mainly on RTO's due to engine failures/fires. Of course, there is only so much that the simulator can simulate. Nice article by the way!

[decurion]

You are correct. Pilot simulator training often presents RTOs as engine-related events while the Takeoff Safety Training Aid (1993!) gives recommendations about other failure conditions to consider. The majority of all RTO accidents were not related to engine problems. In these cases it is possible that the pilots were not fully prepared to recognise cues of other anomalies during takeoff. Pilots often interpret these other anomalies (like a tire burst) as events that threaten the safety of flight and decide to reject the takeoff at any speed. Indeed it is not easy to put these other than engine failure anomalies in the simulator.

[GlueBall]

Practical reality suggests that at V1 there is neither time nor sufficient remaining pavement to intelligently decide whether the airplane will fly or not.

So there is nothing to think about, but only to remove your paw from the thrust levers/throttles by V1 and to keep your paw off the thrust levers/throttles. :ooh:

[A37575]

Have long since retired; but during the 50 plus years of flying experience which included the careful study of accident reports and countless papers on the dangers of high speed aborts, I have always conditioned my thinking to continuing the take off from 15 knots below V1 unless I was absolutely certain the aircraft would not fly.

One could speculate on how to define how you would know for certain if the aircraft would not fly. It all gets too hard. While the 15 knots below V1 figure was always in my mind it was a personal private choice and I never told the first officer. My point being to avoid a legal or company SOP argument recorded on the CVR. There have been many instances of fatal overuns caused by stuffed up aborts near V1 but very few of clipping an obstacle in the take off splay in the go situation.

[homebuilt]

However there is at least one case when a T/O rejection above V1 maybe saved lifes. About 10 years ago or so, an Air Liberté MD83 stroke a Shorts 330 at Roissy CDG, France. Basically the MD was performing its T/O roll after having had his T/O clearance when ATC did a tremendous mistake, allowing a Shorts 330 to line up from a mid position taxiway on that same runway. Nightly operation. Visibility less than average. Language misunderstanding (french language ATC <-> MD83 vs english language ATC <-> Shorts). The MD's left wingtip stroke the Short's cockpit, instantly killing the unfortunate F/O. Although the MD was a few knots above V1 its crew chose to abort their T/O and I think they took the fair decision as 1/3 to 1/2 of their left hand wing was torn off. And as they were light on a pretty long runway they managed to come to a full stop before the runway end.

Had they chosen to continue their T/O, none would have been able to say the airplane would have flown safely.

H.

[decurion]

The final report on the high speed RTO overrun with a PSA Airlines CRJ2 at Charleston on Jan 19th 2010, has been released: DCA10IA022 (http://www.ntsb.gov/ntsb/brief.asp?ev_id=20100121X82958&key=1)

From the report:

The Capt. stated that he did not think the first officer had called out V1 before he initiated the RTO. The F/O stated that he thought that the RTO was initiated before reaching V1 and that he knew that an RTO should not occur after reaching V1.

NTSB Report: “The captain initiated a rejected takeoff (RTO) about 5 seconds after he started moving the flaps and when the airplane was at an airspeed of about 140 knots, which was 13 knots above V1.”

[aterpster]

Then there was the TWA L1011 at KJFK (13R) that "aborted" just after liftoff. That was a totally asinine decision. The runway length and the benign overrun area (at least that day) saved their bacon in spite of themselves. It destroyed the aircraft, though.

I was astounded that both TWA management and the FAA supported this utterly insane act by the captain. The NTSB, though, saw it through untinted glasses, if I recall correctly.

[Gulfstreamaviator]

I operate a Gulfstream, and need a few thousand feet.

I operate from 12,000 ft of paved surface, I could do a touch and go, and still have room to spare.

Horses for courses..... glf

[decurion]

Aterpster. I think you are referring to the following case:

IMMEDIATELY AFTER LIFTOFF THE STICK SHAKER ACTIVATED, AND THE FIRST OFFICER, WHO WAS MAKING THE TAKEOFF, SAID 'YOU GOT IT.' THE CAPTAIN TOOK CONTROL, CLOSED THE THRUST LEVERS, AND LANDED. HE APPLIED FULL REVERSE THRUST AND MAXIMUM BRAKING, AND TURNED THE AIRPLANE OFF THE RUNWAY TO AVOID A BARRIER AT THE END. A SYSTEM DESIGN DEFICIENCY PERMITTED A MALFUNCTIONING AOA SENSOR TO CAUSE A FALSE STALL WARNING. THE SENSOR HAD EXPERIENCED 9 PREVIOUS MALFUNCTIONS, AND WAS INSPECTED AND RETURNED TO SERVICE WITHOUT A DETERMINATION ON THE REASON FOR THE INTERMITTENT MALFUNCTION. THE FIRST OFFICER HAD INCORRECTLY PERCEIVED THAT THE AIRPLANE WAS STALLING AND GAVE CONTROL TO THE CAPTAIN WITHOUT PROPER COORDINATION OF THE TRANSFER OF CONTROL.
NTSB REPORT AAR-93/04

I don’t think it is a true RTO as the aircraft already left the runway. Still it is interesting to notice the reaction of the co-pilot on the stall warning in the light of many (also recent) occurrences involving inappropriate reaction to stalls.

[aterpster]

decurion:

I don’t think it is a true RTO as the aircraft already left the runway.

Having taken off the same aircraft (probably the same tail number) from that runway many times, my subjective conclusion would be a rejected takeoff. My conclusion is supported by the NTSB investigation into the accident:

The NTSB title of its investigation report is:

Aborted Takeoff Shortly After Liftoff

Finding Number 12 of the report:

12. The captain made a "split second" decision to reject the takeoff by reducing the engine thrust. His decision was very likely based, in part, on the perception of available runway to stop the airplane.

[decurion]

aterpster (http://www.pprune.org/members/297138-aterpster), I think you are right. Interesting case by the way.

[BarbiesBoyfriend]

homebuilt

Good post. I remember that the Air Liberte sat near the end of 27L for a year or so, the Shorts was eventually broken up there.

27L is a looooong runway. Why not stop, if you need to?

Remember the 748 that stopped well after V1 at (I think) East Mids?

Capt was congratulated, publically at least. :suspect:

[BOAC]

Remember the 748 that stopped well after V1 at (I think) East Mids?

Stansted

Capt was congratulated, publically at least
and professionally.

[safetypee]

BBf, BOAC; Re HS748 Stanstead.
Read the AAIB report carefully, re decisions and actions (3/2001 (EW/C98/03/7)).
With hindsight, the decision was ‘incorrect’ (yet all decisions at the time are correct from the perspective of the decision maker), however the resultant fire from which a correct decision might be concluded, was perhaps exacerbated by other ‘erroneous behaviors’ in procedure.

Learning points from this accident are the power of startling or extreme graphic events to bias decision making, and that on balance a Go-Minded attitude (with correct engine shut down procedure) should provided a similar or higher level of safety than a decision to land straight ahead on a long runway.

In similar circumstances – a surprising event with a long runway ahead – another Captain related that he did not believe that the cues (noise and vibration from a thrown tyre tread) could be generated by a normal aircraft – hence the decision to a land ahead – surprise and incomprehension.
However, on a shorter runway the takeoff would have been continued, but no reasoning for the change could be offered.
This indicates the complexity of the decision making process, highly dependent on the perception of the situation in a time pressured environment, and bias – our predispositions towards particular actions (knowledge and understanding of risk – see the Training Aid).

I doubt that extensive simulator training would ever cover the range of scenarios, nor generate the requisite surprise; thus it might be more effective to practice the drills associated with stop or go in relation to V1, and as the Training Aid suggests, be Go minded – education and knowledge to dispel inappropriate bias.
In addition, from the report (#1), keep the decision choice to a simple ‘if – then’ option, which entails considering the reality and probability of operational scenarios – keep the SOPs practical.
Human judgment should still the best solution in ‘unforeseeable’ circumstances, and although we are ‘ground dwellers’, flying – like the birds – offers another dimension for safety, as well as more time (and longer runways) for the subsequent choice of action.

[BOAC]

I don't want to drag out an old accident here, sp, but my copy tells me that the action to re-land was considered 'sensible in the circumstances' by AAIB and I recall the Captain telling me that it had been suggested to him unofficially that the wing may well have burnt through during the positioning to land after continuing. I judge the decision a good one.

It is, after all, what we are paid to do as Captains - to take decisions at the time for which we stand responsible and sometimes 'normal' rules need to be abandoned. 'Never say never'?

[safetypee]

BOAC, re HS 748 accident, which the AAIB investigated and reported circumspectly – avoiding ‘error’ and blame.
I don’t have a problem with the Captains decision in the particular situation, but what about a shorter runway etc, etc. Nor do I have a problem with discarding standard procedures in ‘non standard’ conditions.
The HS748 accident suggests that the cues invoking surprise might not have been considered or realized in training – and perhaps not even possible for any aircraft type.

These are the areas that require improved RTO training. The Training Aid provides a range of situations and considerations but perhaps fails to provide adequate guidance on probabilities of occurrence and human behavior aspects.

The introduction/use of ‘if unsafe or unable to fly’ IMHO is detrimental to safety.
GlueBall touched on this (#4); it is unlikely that sufficiently reliable cues or time will be available for a decision. Environmental issues, i.e windshear, might be judged a failure in the decision to commence the take off, if so then we need to improve awareness and risk assessment. Similarly a truck or even an elephant on the runway (I’ve experienced one of those) is a real but low probability event, but again aspects which might be determined before V1 thus avoiding the possibility of rejecting ‘above V1’.

The report (#1) appears to identify problems with pilot’s inability/reluctance to change the decision/action process at V1. Perhaps because of poor speed awareness, or where correctly deciding to reject before V1, slow actions or incorrect technique result in an overrun; again, these are basic training issues.
However, IMHO the dominant issue is dealing with surprise – shock, even fear, an aspect which can be in most abnormal / emergency situations.
Thus, how do we train pilots to manage surprise?

[GlueBall]

"...decision was very likely based, in part, on the perception of available runway to stop the airplane."

Be careful with that illusion, because past V1, especially at max gross weight, [eg:B747] the available brake energy is in La-La-Land. The brakes will go on vacation before the pavement ends...and then you just keep on rolling and rolling! :eek:

[MountainBear]

There is a tremendous amount of outcome bias in this thread.

What's a good decision by a captain? One that saved lives.
What's a bad decision by a captain? One that cost lives.

The rightness or a wrongness of a decision in the minds of too many people is simply a function of the results that followed from it. But hindsight is always 20-20. That has absolutely nothing to do with safety as a process.

The key question is does any improvement in procedures or training make a difference in safety outcomes when the outcome of the relevant decision making is unpredictable in advance. Faced with a whole host of unknown factors successful outcomes often don't come down to training or procedures but old fashioned luck. Honest captains admit this.

Not that here are many honest people around, captains or no. :sad:

[BOAC]

I don’t have a problem with the Captains decision in the particular situation, but what about a shorter runway etc,- nor did the AAIB!

SP - mountainbear has summed it up neatly in his para 2. If we are to talk forensic 'what-ifs' years after ('shorter runway etc'), 'whatif' the wing had fallen off downwind, having had 3000 ft or so of tarmac to land on?

As I said in my previous last para - when the chips are down you make the decision and mountainbear's para then analyses it. Short of 'training' by popping a large paper bag behind PF in the sim, that sort of 'surprise' is what the human brain copes with, either successfully or not. (Interesting to see a scientist write the software for that decision.)

Losing 2 motors on a heavy 74 out of Brussels and stopping at or above V1 brings the probably inevitable crash scene inside the airfield boundary - right or wrong? I do not wish to judge.

[aerobat77]

V1 is a threshold where below this you have better chances to survive when you abort, above this you have better chances to survive when you continue. it is not a guarantee that all will be nice when you continue above v1. when e.g you have an all engines fail , wing seperation etc. you need not do discuss the V1 - but when this happens there is no procedure anymore that gives you a chance to handle this situation, you may simply crash and burn.

we have situations where the pilots ( e.g concorde crash) did all right regarding V1 and the outcome was killing all the people.

nevertheless- there is no time to think about this on takeoff roll and in the vast majorities of failures continueing above v1 gives you a better chance to make it.

[A37575]

Short of 'training' by popping a large paper bag behind PF in the sim

Actually that is not so far fetched as it sounds. In the 737 sim I was in, the captain was PF and had just rotated. The tipping movement of the simulator caused a defective catch to fail on one of the servicing panels at the rear wall of the simulator. The servicing panel fell on to the simulator metal floor with a loud crash and with that the captain pulled back both throttles and tried to land straight ahead. He made it, too.

At the subsequent Court of Inquiry (aka the de-briefing) he said he thought the loud crashing noise was a simultaneous severe damage loss of both engines and that in his professional opinion the 737 doesn't fly too well with no engines so he put it back down real quick and survived to tell the tale.

[MountainBear]

nevertheless- there is no time to think about this on takeoff roll and in the vast majorities of failures continueing above v1 gives you a better chance to make it.

Well if that's the case why don't automate the whole thing. If we are going to treat airplanes as nothing more than flying dice and the sky as the great gambling table why is there a pilot at all. Surely a computer can calculate the odds much more quickly than the human mind once the results of studies such as the one at hand are programmed into it.

Once we put a human being inside the cockpit everyone has to accept that "to error is human". I'd go one step further than BOAC: Not only do I not wish to judge, I think it's unfair to judge. It strikes me as a grand game of "gotcha!" were the only major difference between the person who is found out and the person who is not is luck.

In saying that I don't want to suggest that luck is always the determining factor. Sometimes there is clearly a deficiency/superiority in skill or training. But according to the article in the OP a long-haul captain expereinces such an incident once every 25 years. If we as as a community are unwilling to accept that when faced with a once-in-a-career event the very human pilot gets it wrong then lets stop all the hand-wringing and let the computer do it. At least you won't have the captain to kick around any more on that score.

[homebuilt]

"...decision was very likely based, in part, on the perception of available runway to stop the airplane."

Be careful with that illusion, because past V1, especially at max gross weight, [eg:B747] the available brake energy is in La-La-Land. The brakes will go on vacation before the pavement ends...and then you just keep on rolling and rolling!

On the jet airplanes I'm flying / used to fly on, all within "H" category, a chart shows the Vmbe: max brake energy. Of course V1 must be lower than Vmbe, it's mandatory (as well as V1 equal or higher than Vmca). On the airplane I'm currently flying on, V1 is around 160 kts at MTOW (ZP = 0, ISA) and Vmbe ~ 185 kts in the same conditions.

If I understand, that means that if I reject my T/O above V1 on a balanced runway I'll get out the runway but my wheelbrakes will be working as long as I didn't reject my T/O at a speed higher than Vmbe.

Just my two cents.:ok:

[Gulfstreamaviator]

My take off run is in the order of 2,500ft, and the runwal length is 12,000 ft, my V1, can be in the order of 1,000ft.
In earlier types flown V1/VR was within 1 second of each other, but currently now about 5 seconds.....and still 10,000 ft of runway ahead.

I was taught that the fire department do not have ladders high enough to reach you in the circuit, but can drive fast enough to catch you on the ground.

Horses for courses.

I was interviewed for a corporate job in India, a few years back, and was asked by CO flying of the company in question, would I ever STOP after V1...I gave the above explanation. he was not happy.A few years later he crashed and burned, perhpas because he followed the check list. The check list is the best know solution for some but not all problems.

The definition of V1, is DECISION SPEED etc, etc, not GO speed.


glf

[de facto]

John,

Lack of basics is a killer isnt it?:E
Doesnt your specific aircraft type have VSTOP and VGO speeds rather than a single V1 speed more pertinent to airliners types?
I dont believe your on the spot assessment of excess runway available in case of lets say blown tires is the way forward to a sound decision,especially with your seemingly over confidence of your aircraft performance.
For your info,on my type,reduced thrust(assumed temp) is safer for both STOP and GO decision,so overrun events have none to do with these incidents..

[johns7022]

De Facto - You can either hire pilots that can look out the window, decide how much ice is on the wings...or simply hit the boots when the ice light comes on..

You can have all your pilots nick a fuel truck, and fly a broken wing off the ground, killing everyone right after V1, or you can hire a pilot who recognizes he's got an unflyable plane..

If your going to make the argument that all decisions/scenarios are in the checklist I can sit here and give you writer's cramp to the contrary...

Either way, you won't be convinced, because in the end, you need guys that take orders and get along..... so a few planes crashing once in a while flown by 200 hour pilots is still cheaper then packing the cockpits with 10000 hour captains who tend not to screw up....

[Brian Abraham]

The definition of V1, is DECISION SPEED
No, it ain't.

V 1 means the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.

To interpret, the decision has to be made prior to V1.

[johns7022]

The point is moot....just because a plane will accelerate to V1, does not mean you have a plane that will fly after VR...

The pilot needs to do more then just push the throttles forward and look at the airspeed indicator for all his answers....

[Roger Greendeck]

John's earlier point about what V1 actually means on some aircraft is quite valid. It does not mean V1 for a balanced field. Under some certifications you get take off field length (TOFL) which is the min runway required. It also has a V1 for that length. If you are taking off from a space shuttle diversion its still the same speed. In that case there may be good reasons to stop after V1. Unfortunately you don't have any data to go on but if you have enough length for TOFL plus landing distance required there is a better than average chance you can stop.

What about cases such as a flock of birds getting airborne and crossing the runway just as you are about to rotate. If you abort the plane is fine is you go you give yourself multiple bird strikes.

Just like everything else in the manual you have to take the information and apply it to your circumstance.

[de facto]

Greendeck,

You are talking about balanced field v1,which is correct as you will have runway remaining if you stop AT V1 or maybe after( if you are not at the runway length limit weight in the first place or if you are not in a improved climb scenario).

John doesnt seem to have any knowledge of reduced thrust performance due to the aircraft he's flying or because of his company OPs or just lack of knowledge.

However,55% of overruns are due to reject after V1 speed...(and for reasons other than serious problems).80% not engine related.

Your flock of birds surely is NOT a strong enough reason to initiate a highspeed RTO...why not delay your rotation?rather than guestimating your stopping distance?
What will you tell your CAA, when you are facing them?i rejected and wrecked a multimillion dollars aircraft,possibly killing many onboard because you thought that the birds MAY be ingested and fail both your engines?

But there again,pilot decision.
Now because I am soooo nice and looked into my files,here is a link to your local US FAA,hopefully people will read again:E

http://www.faa.gov/other_visit/aviation_industry/airline_operators/training/media/takeoff_safety.pdf

[decurion]

This presentation by Boeing could be interesting regarding the discussion of V1

http://www.captainpilot.com/files/BOEING%20PERFORMANCE/Range%20of%20V1.pdf

[BOAC]

Following our look at the 748 at Stansted which did abort when airborne, a friend has sent me details of a sad fatal accident to another 748 with a similar RR Dart disintintegration which DID continue and subsequently crashed killing all on board.

The Transportation Safety Board of Canada report number H90001, Quebec Air F27B Rolls Royce Dart engines, CF-QBL Flight No 255
QuebecCityAirport, 29 March 1979
The flight lasted 1min 12secs after lift off.
Fourteen passengers and three crew died in the crash.
"At time 36 seconds after brake release there was a loud bang from the right engine as it disintegrated and a severe fire developed. The aircraft was at approximately 103 kts and 40 feet above the runway.
At time 42 seconds, The captain started the engine failure/fire emergency drill.
At time 45 seconds, the tower controller who had noticed flames from the right engine advised flight 255 that the right engine was on fire and authorised them to land on any runway.
From time 50 seconds to 1 minute 05 seconds the crew attempted to raise the landing gear which never came up.
The aircraft climbed to about 120 feet above the runway elevation and started a right turn, apparently in an attempt to complete a short circuit, remain visual and execute an emergency on the airport.
At time 1 minute 14 seconds the captain called for the propeller to be feathered. Up to this point the crew did not know that the right engine had separated at the first stage impeller and the forward section of the engine along with the forward section of the engine along with the propeller and some cowling had fallen onto the runway
At time 1minute 24 seconds the No 1 fire bottle was fired and the aircraft continued in a right turn at about 100 feet above the terrain at a very low airspeed. The engine fire continued.
As the aircraft approached the College de Sacre Coeur, the angle of bank increased and the aircraft started to descend until impact.
Impact occured in a nose down, right wing low attitude at approximately 80 kts.
A fierce fire broke out and most of the fuselage forward of the wing was consumed by fire."
The Rolls Royce Dart engine had suffered an uncontained failure.

I do not presume to question or comment on events or actions except to suggest it might be worth putting into the equation for decision making?

[Sciolistes]

In earlier types flown V1/VR was within 1 second of each other, but currently now about 5 seconds.....and still 10,000 ft of runway ahead.
How come you have so much runway remaining with a 5 sec gap between V1 and Vr? If you could stop at Vr the I would have thought that the speeds would be coincident.

[johns7022]

Defacto...

Not all pilots are equal...sorry but true.....if you think that a 200 hour FO pulling the nose up is on par with a 10,000 hour pilot pulling the nose up, because both are 'doing the numbers' ...you just don't know....

It's become such a running joke on the sims that an 'emergency' these days, is a raw data, no A/P approach...you know the same kind of approach a guy will do in a Cessna 172.....

So let's not go down the path of using some example of some African outfit, who did an over run, and busted up the plane, because I can sit here and cite example after example of guys who crashed a plane that could have been stopped, but decided to fly it to the scene of the accident instead of rolingl it there...

The simple fact of the matter is that a corporate outfit that pushed the throttles forward, then realizes a few knots past V1 that he's got a fire, looks ahead to see 8000 feet of runway, is a perfectly happy non event.....

If you want to plan a reduced thrust departure, where the balanced field is in the weeds, and thus a crash, into that road on the other side of the overrun, that's your business...whatever it takes to stretch those engines right? But it's a hard sell for those of us who didn't get our licenses yesterday to make the case that your flying safer then us....because you not..

Your purposefully putting passengers at risk by using up more runway, reducing obstacle clearance, forcing a go decision because you know a stop won't make it...then forcing the 200 hr FO on this leg to hand fly that whale with one good 25000 hour engine out there...while on fire, and putting the gear up, cleaning it up...and flying around the pattern in the soup, looking for another ILS, that will now be flown single engine..

Yeah sure....

[galaxy flyer]

Johns7022

You persist in making obvious your total lack of knowledge of take-off performance under Part 25 and complete ignorance of reduced power or derated power performance. By definition, the field length CANNOT be "in the weeds". In an assumed temp reduced power take-off, the plane will, be definition, perform better than the calculations. Any reduced power take-off MUST meet all the runway and obstacle clearance criteria using he reduced power setting without resetting the throttles.

I'll agree with anyone here that in exceptional cases, aborting after V1 is a proper decision. But, that is exceptional cases, not the standard engine failure. I also stipulate business jets on long runways that far exceed the BFL of the day have an inherent ability to stop. In the C-5, every take-off had about 30 numbers calculed, including Vmcg,Vmca, refusal speed, AEO field length, critical field length.

Before advocating stopping after V1, do you calculate a refusal speed and ASDR for every take-off? Do you calculate a Vmcg for each take-off where a wet runway, contaminated runway or crosswinds are factors? Do you use a runway analysis for each runway, including any special departure procedurefot terrain? Do you brief and do sim practice on flying the SDP?

If not, you're just stringing a whizzer on "I can look out the window and judge that I can stop". Also, johns7022, just how many ASDR equals ASDA take-offs have you done to judge your stopping distance? Citations don't stop that well, if my distant memory of 2,500 hours in CII serves.

GF

[galaxy flyer]

Just how many airplanes hit fuel trucks and crash having tried to continue the take-off on your planet? Here on Earth, it is just about unheard-of. But, going off the end due to poor brake usage (stopping technique KMDW), due to trying to reset the flaps past V1 (KCRW), going off the end because of lining up on the wrong runway (KLEX), going off the end by aborting past V1 when continuing the take-off would have been safer (read Boeing's report on aborted take-offs) is all too common.

GF

[johns7022]

Tell you what Galaxy....let's go outfit a plane where the autopilot performs the take off...if nothing on the panel lights up prior to V1, it will pull the plane off...

So when you get to the end of the runway, with a fast leaked tire, creating drag...all the while the plane burned up 10,000 feet of runway trying to get to V1...then we can discuss balanced field, running the numbers after you crawl out of the crash site.....

[galaxy flyer]

John7022

I'll take your answer to mean you don't do, and probably cannot do, the proper calculations required. I, and others here, never said that pilot's should be "autopilots" flying planes, but that the calculations are necessary and should be followed. As Boeing noted, continuing too early by 1 knot might mean a lower screen height, while trying to stop 1 knot past V1 might mean an overrun of 40 knots on a field-length limited take-off.

I suggest you do some real study on take off performance instead of selling the idea that pilot's should use "Kentucky windage".

Statistically, you are in greater danger trying to stop and overruning than continuing the take-off. BTW, I have lost a tire on take-off, we found out about it from Shanwick when they got a call from Karup tower saying that they thought the debris on the runway was ours.

GF

[johns7022]

Galaxy, the weakness in your thinking is that a rolling aircraft to V1, somehow guarantees a flying aircraft at VR..

I can take the wings off a 737 and go up and down the runway accelerating to V1 all day long, but we know it won't fly....

Well I guess the way you were taught is that all you gotta do is roll down the runway and look at the airspeed indicator...when it hits V1..despite the bomb/rpg that just took half your tail off and 9000 ft of runway ahead....your pulling back on the yoke.

I suggest rather then focusing on on balanced field theory and aircraft certification....you do a few take offs in a plane with the airspeed indicator covered up....you might be surprised how some stick and rudder skills can do wonders for your flying.....

I think you have been sitting in a box too much.

[galaxy flyer]

With 11,000 hours in fighters, biz jets, heavy transports, civil and military, I'll stack my experience and training against yours, any day.

None of us has said that we are automatons that ONLY consider what the ASI says, we do think, but we also learn from the totality of aviation. We have learned that continuing is more likely than not to be a better choice. When the wings come off after hitting your fictional fuel truck, I'll stop, regardless of the speed. And I'll teach others to do so.

Enough with your straw man arguments that bear NO resemblance of reality. Performance calculations, not a guess out the window, guide the pros.

GF

[johns7022]

I doubt your concession NOW to the possibilities that I presented, that would most certainly guaranty your killing a plane load of people by continuing on...will NOW translate into a post V1 RTO in your future....you've taken an entrenched position that post V1 RTOs are BAD, horrible and ugly.

You can't argue against it for a day, then say...'well ok, I would do it, I guess, the but odds are I won't make it, I guess, but gee whiz, it's not a good idea...because too many other guys rolled into the grass...so I guess I might too....so uh, well, I'm not a robot, so uh..well..gee...I would probably just go...maybe'

For me this isn't rocket science...I hear a bang, I haven't rotated yet, I see 5000 ft (or much less)of runway ahead, I stop...big deal.

[Sciolistes]

For me this isn't rocket science...I hear a bang, I haven't rotated yet, I see 5000 ft (or much less)of runway ahead, I stop...big deal.
The salient points are, unlike just about any other manouevre, that there is very little margin for error with and RTO. Any delay or mistake will likely end in an overrun. If you have time to think between V1 and Vr then you probably don't have enough runway. So it isn't rocket science, unless you are absolutely certain that the aircraft won't fly, the lesser risk is to accept an overrun and the relatively small number of deaths and serious injuries that result. It is a stark choice!

[johns7022]

It's a fallacy that an RTO is a danger fraught maneuver.....pull the levers back, pop the TRs, add brakes...

An RTO is dangerous if you purposefully reduced thrust and stretched your balanced field into the weeds to keep those 25000 hour engines running another 10,000 hours........

[BOAC]

can take the wings off a 737 and go up and down the runway accelerating to V1 all day long - I fear this poster may be shooting from elsewhere? Thinks - I wonder if he/she has any idea where the engines are on a 737? Bag of marbles in the Christmas stocking perhaps?

[Sciolistes]

I am with you on the airmanship thing and not blindly following procedures without any understanding of what is going on. But according to my training, an RTO near V1 is a risky manouevre. The FCTM backs this up as does the theory that I was taught during my ATPL ground school. I would honestly be interested to study any other references you can provide.

As a pilot, my assumption is that an RTO initiated after V1 will result in an overrun.

[galaxy flyer]

John7022

I have no doubt, in the Global on 10,000 feet of runway, I hear a "bang" at V1, I'd stop, too. Just as, if a fuel truck leaps out in front of me and takes the wing off, I'll stop-- no choices there. But the real conversation is on the ASDR-limited (field length limited) and an engine rolls back or you get a simple fire light, then what? Take an overrun when the basic airworthiness is not in question. The plane and passengers are safer airborne and landing out of a controlled approach. Had the EMAS not been place at KCRW, the CRJ would have gone over the edge with loss of life. That is the real life story, not your silly extreme straw man arguments.

GF

[Non-PC Plod]

I come from the rotary-wing world, and I thought we were light years behind you fixed wing fellas in terms of MCC procedures, but I'm quite surprised that no-one on this thread has mentioned either a departure brief or SOPs.
SOPs help to save us from making rash decisions in the heat of the moment.Thats why we normally follow them.
If we are in a situation where there is a better solution than to go with the SOP - for example a 5 mile long runway, do you not brief it as a crew in advance, rather than just cuffing it?
eg:
"Today, we have a 5 mile long runway, so in the event of an engine malfunction after V1, I will delay the go/nogo decision until.........."

[PEI_3721]

Discuss further issues of rejected takeoffs, human error, misguided thinking, or poor attitude, where the latter does little to promote professionalism in our industry.

No; reject, add to ignore list. Choose a safer option, less risk of high blood pressure, head banged against the wall, or frustration of declining standards in our industry.

P.S. on reflection, if some of the more extreme discussion, as above, involves ‘real’ professional pilots, then there is an urgent need for education, which the thread initiating post, report, and FAA training aid seeks to implement.

[GlueBall]

"I see 5000 ft (or much less)of runway ahead, I stop...big deal."

...just because you still see lots of pavement ahead does not ensure that you will stop before it ends, because when your brake energy has been dissipated you can stand on the pedals and you will continue rolling with zero brakes.

Typically there's an average of a ten knot spread between V1 and VR . . .and you're telling us that in that 2 second interval you could decide that the airplane would not be able to fly . . . ?

A nut case B747 captain with your mentality at Bruxelles had heard a bang [compressor stall] after V1 and had imagined that the airplane would not fly, then he had aborted more than 10 knots past V1. . . destroyed the airframe and had narrowly averted the deep end drop unto the rail tracks and high tension wires.

[johns7022]

Ah yes the failing brake argument....that brakes are perfectly reliable for landings, but during RTOs your brake disks turn into marshmellows...but not on landings...only RTOs.

[galaxy flyer]

The energy absorption in a RTO is, at least, twice that of a normal landing in a B747 class plane. RTOW for a long-range plane will be on the order of 75% greater than landing weight, the Vref will be, on the order of, 25-35 knots less than Vr. The energy absorption is huge, on the order of 33 million ft/lbs per brake. I don't know the specifics on the 744, but on the C-5 taxi-out will raise the brakes by 100-150C, depending on turns, weight and length of taxi. A heavy jet transport is streets away from your Citation. A RTO at heavy weights will raise the temps to the fuse plug blow-out temps.

You continue to express opinions on subjects you have no training and no relevant experience and tell those with the training and experience that they are wrong, or worse, dangerous. Please spend time learning about FAR 121 operations and the relevant certification background. Reduced power take-offs and "on condition" maintenance appear to be special bugaboos, both common procedures, even on several FAR 25 certified business jets and regional jets using the same engines.

Airlines are not the safest form on transportation because they do stupid things, have incompetents at the helms.

GF

[johns7022]

Yeah...I am sure that the FAA certifies jets so that they can brake effectively at gross, from V1, all day long, year after year, but if you go over 5-10 kts...everyone is a goner....

I think Boeing is putting you guys on...for some reason they would rather have you guys fight the fire around the pattern then pull the levers back and stand on the pedals..

It would be curious to know the real reason why...

[Old Fella]

Dont think so. Example MTOW for a B747-200 is around 370,000 Kgs. MLW is around 285,000 kgs. I think you meant RTOW can be around 25% greater than MLW.

[SNS3Guppy]

Yeah...I am sure that the FAA certifies jets so that they can brake effectively at gross, from V1, all day long, year after year, but if you go over 5-10 kts...everyone is a goner....


What exactly is your point, here?

Brake effectively at gross what? Are you saying that a fully loaded airplane can do maximum braking "all day long?" If so, you're absolutely clueless on the subject. Particularly with respect to a rejected takeoff.

This subject has been discussed at great length, and use of the search engine may educate you more than attemtping to set straight your misguided ideas. If you can take the approach you do, you can only do it from a standpoint of utter ignorance of the dynamics involved in a rejected takeoff, as well as complete ignorance of takeoff dynamics and performance calculation.

The braking effectiveness isn't the issue with respect to rejecting a takeoff after V1. Having insufficient runway is certainly an issue.

Boeing is shining everyone on, you say? Shining everyone on with accurate, proven data? Shining everyone on by performing to Part 25 certification standards? Shining everyone on by enabling crews to calculate the performance for their takeoff on a given day, with a given payload, a given fuel load, a given set of ambient, environmental conditions? Really?

When we calculate our takeoff data, we do so given real world conditions, and real world aircraft performance. We know what the aircraft can, and can't do. What it can do is perform a rejected takeoff, at the hands of the crew, prior to V1. What it cannot do is safely allow the crew to perform a rejected takeoff after V1. Insufficient runway remains.

Apparently you don't understand this.

We have a major advantage continuing and coming back to land, rather than rejecting. When rejecting, all the runway is behind us. When coming back to land, it's all out in front. In case you weren't aware, that's a good thing.

[Spendid Cruiser]

http://www.skybrary.aero/images/Vancouver.jpg

The captain called “reject” 1.3 sec after the loss of power and initiated the associated action 0.8 sec later by retarding the power levers to idle as the aircraft was accelerating through 172 kt 7,300 ft along the runway. The flight engineer, noting that lights indicating that the thrust reversers were deploying had not come on, called "No reverse" and immediately moved the spoiler handle back. As a result, the spoilers were deployed and the autobrake system activated. At this point, the aircraft had accelerated to 175 kt and was 7,850 ft down of the runway, and 3,150 ft from the end.
Reverse thrust power was applied as the aircraft was decelerating through 140 kt, 1,850 ft from the end of the runway.
The autobrake began applying pressure 1.8 sec after the captain pulled the power levers back to idle. This activation of the autobrake was the direct result of the flight engineer manually deploying the spoilers when he noted the thrust reversers had not been selected. The thrust reversers were not deployed until 3.5 sec after the power levers were retarded. The brake pedals were not used by the crew during the rejected takeoff.
Although the Abnormal Procedures checklist current at the time of the accident did not call for immediate manual activation of the spoilers, the flight engineer’s actions to do so, in accordance with airline standard operating procedures (SOPs), greatly reduced the amount of overrun. The engine maintenance records indicated that the three engines on the aircraft had been maintained in accordance with the manufacturer's recommendations;

[homebuilt]

Ah yes the failing brake argument....that brakes are perfectly reliable for landings, but during RTOs your brake disks turn into marshmellows...but not on landings...only RTOs.

Somehow yes, because you have to take into account the huge difference between TOW (MTOW) and LW (MLW) on an heavy transport airplane. Speaking of the B744 for example you have a MTOW close to 400 metric tons (396800 kgs), vs a MLW of 285700 kgs (with actual LW around 250 - 260 metric tons in the average).

If you can compare the brake energy required to stop a close to 400-ton airplane starting at ~170 kts (~V1 at MTOW) - the case of the RTO -, and the brake energy required to stop the same airplane but at 260 tons, starting at ~145 kts (~Vref at that weight), with the cinetic energy formula 1/2 M V2, that gives you a balance of a little more than 2 against 1.

Roughly speaking, that means that on such an airplane, in order to be able to reject the take-off brakes must deliver a little bit more than twice the energy that they have to give for a max breaking landing (most times I perform landings using the autobrake set to 3 on a range that shows 1,2,3,4, MAX, and .... RTO).

That's all the difference and that's why a MTOW RTO at V1 is likely to finish in the grass with the landing gear burning...

But as I told earlier with the example of the MD83 colliding the Shorts 330, it's airmanship management and indeed sometimes you won't have any other choice but rejecting T/O whichever the speed... But in that case one has to be aware of the potential consequences.

[johns7022]

Put away the crash reports...more airliners FLY to the scene of the accident then roll to the incident on departure.

Besides...if you had to sit in the back...are you convinced the new FO is better prepared to pull the levers and add brakes...or hand fly a broken aircraft into the soup?

[homebuilt]

Besides...if you had to sit in the back...are you convinced the new FO is better prepared to pull the levers and add brakes...or hand fly a broken aircraft into the soup?

No way: in the airline I'm flying for SOPs stipulate that whichever the Pilot Flying is (Capt or FO), the RTO is carried out by the Capt, the FO handling the monitoring tasks and dealing with coms.

[Spendid Cruiser]

Put away the crash reports
And yet there you are arguing a case that has already resulted in an overrun.
...more airliners FLY to the scene of the accident then roll to the incident on departure.
Obviously, how is that relevant to the discussion?

[galaxy flyer]

Old Fella

I was comparing RTOW on longish runway to a normal, end of cruise weight--and still off. Using the later posting, 60% looks like a reasonable number. In any case, Splendid Cruiser presents some good info.

SSG, Johns7023

Do try to learn and stop banging your spoon on the table. Yes, more planes of all types FLY to the scene of the crash, but THE DISCUSSION HERE IS ON REJECTED TAKE-OFFS!

Out of curiosity, at what speed did they overrun at CYVR? Good catch on the FE's part. Johns7022, you could learn something about CRM and the reason crews work better!

GF

[Brian Abraham]

GF, they went off the end at 43 knots. Full report here, and highly relevant to the discussion here - not that our wannabee microsoft driver expounding here would understand.

Transportation Safety Board of Canada - AVIATION REPORTS - 1995 - A95H0015 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/1995/a95h0015/a95h0015.asp)

When comparing the energy levels of a reject compared to landing at max permissible weight need to remember the .5mv^2 formula. It's the v that's the killer.

[de facto]

John,


Troll Alert:e

[GlueBall]

Ah yes the failing brake argument....that brakes are perfectly reliable for landings, but during RTOs your brake disks turn into marshmellows...but not on landings...only RTOs.

Exactly correct, because at 400t TOGW [B744] and RTO brake application 10+ Knots beyond V1 you're in La-la-Land....the total available brake energy will be dissipated BEFORE you get to the end of any "extra" pavement. But during landing at 285t Max Ldg Weight [115t lighter] your brakes will NOT fail.

[johns7022]

The conversation has always been an RTO vs Flying it off...those are your choices...

If you do a little study on how planes are flight tested for RTOs, it's pretty much Joe Test Pilot accelerating up and down the runway to V1, then applying brakes.....then recording the distance data, checking the brakes for issues ect.

Now the manufacturer has some flight test numbers of a pilot who say just did 1000 RTOs...he's probably gotten pretty good at them...so some buffers are added to for variables such as age planes, back pilots, older brakes and tires...probably a little for mom.

So let's think about this...with all the runway in the world ahead of you, stopping distance is not the issue...and the difference between V1 to VR is say 10 knots.....do you really think that if your brakes are certified to be 100% reliable to brake from V1, at Max Gross Weight ...that another 5kts or so is going to be the difference in your brakes failing?

If your going to make the argument of not doing RTOs....the proper way to discuss your end is talk about distance, not brake failure, and why so many of you are throwing out your margins with assumed power/derated take offs.

[trex450]

I have never flown anything heavy apart from a few hours once doing an MCC course. I fully appreciate the reasons for V1, runway length, brake energy etc but I can see one immediate reason for rejecting beyond V1. I am delving a long way back to my performance A exam so stand by to be corrected but I seem to remember that you can only use a maximum of 15 kts headwind component for planning purposes. If you are taking off into a headwind of 30 kts and the aircraft V1 is based on braking ability, or runway length, then surely rejecting at 10 kts beyond V1 should cause no problem as the groundspeed is (in this case) 5 kts below the V1 that the graphs have produced.

[john_tullamarine]

If you do a little study on how planes are flight tested for RTOs, it's pretty much Joe Test Pilot accelerating up and down the runway to V1, then applying brakes.....then recording the distance data, checking the brakes for issues ect.

.. from which we can infer that such testing is not in your background ?

do you really think that if your brakes are certified to be 100% reliable to brake from V1, at Max Gross Weight ...that another 5kts or so is going to be the difference in your brakes failing?

.. one might consider brake capability as being a bit like a bucket of money. When you go for the RTO (and we are looking at a critical case here - GW, OAT, wind, slope, etc - clearly, the further away from the critical situation one might be, the better the situation) you start throwing out (large) handfuls of money. When the bucket is empty, it's all over. What the line pilot doesn't know, however, are the real margins inherent in the specific certification.

Point is, if one operates outside the Book, then one is venturing into no-man's land .. the statistical basis for certification provides a measure of protection for the operator and crew (and, by their being glued to the cockpit, the passengers). Outside those boundaries, the pilot (or other relevant person, eg maintainer for maintenance actions) carries a burden of having to justify his/her decisions after the event - I draw the reader's attention to any of a vast number of legal proceedings .. the Air France Concorde outcome in recent days makes for interesting thoughts ?

the proper way to discuss your end is talk about distance, not brake failure, and why so many of you are throwing out your margins with assumed power/derated take offs.

Two different considerations albeit with some linkage in terms of risk.

To talk distance is fine .. but, if the brakes have quit ... that extra distance might not be enough on the day.


For those who might take issue with Johns7022's views, the importance is that such views challenge the conventions and lead to vigorous and robust discussion .. all of which should be useful for Tech Log's educational interests.

Whether he might be right or wrong is not the point ..

If you are taking off into a headwind of 30 kts and the aircraft V1 is based on braking ability, or runway length, then surely rejecting at 10 kts beyond V1 should cause no problem as the groundspeed is (in this case) 5 kts below the V1 that the graphs have produced.

One presumes that you have the data and engineering know-how to justify such an action after the event ?


Point in question is

(a) if things are reasonably "normal", one probably is better served by sticking to the certification paddock as prescribed and described in the OEM AFM and similar documents. Well thought out SOPs provide some measure of protection after the event as well as sound risk management strategies for normal and defined abnormal/emergency situations..

Any suggestion purporting, routinely, to operate outside the norm is somewhere between very stupid and unbelievably stupid.

(b) if things go decidedly pear shaped and out of left field during the flight, then the Commander gets to earn his/her big bucks at the time. The outcome will involve consideration of knowledge (general technical and specific event-related), skill, a measure of luck .. and a bunch of other matters relevant to the specific event

Whether such decisions might cause difficulty and heartache at the subsequent enquiry is a moot point.

One needs to keep in mind that 20/20 hindsight is a wonderful thing, greatly admired by the legal fraternity, and has hung more than a few crews out to dry after the event in which they had barely a couple of seconds to make a critical, usually non-briefed, call ...

[johns7022]

John - Personally I am not a certified test pilot...but flight testing is more then a passing interest and something that I have studied....more to the point I have sought out personal discussions with people who were on the ground changing out brakes during the S550 ground runs at Lake Havisu and others with regard to anti lock brakes, VMO...ect.

I am not here to flout the numbers or suggest everyone willy nilly do what they want in the plane counter to good pilot practice...but when it comes to judgment calls, where it's one bad choice vs another bad choice...then the variables for those choices come into play..the more we know the more we understand, the best we can make a good decision.

If Joe Test pilot can do a V1 RTO for the given conditions....he will stop in X feet...but you will be given Y feet...a much higher number. If they tell you that your brakes will work 100% of the time from a V1 RTO....I can guarantee that 5 knots faster is not some magic wall you have crossed where you go from 100% reliability to 100% failure. It doesn't work that way.

Now maybe stalling speeds are somewhat aerodynamically absolute.....the VMO numbers you get have a 50 kt buffer with a big g force pull back..

So just for the record if you have the runway to stop, but are willing to fly a burning wreck through the air because you feel your brakes will fail, because your 5 kts over V1, I don't agree.

[SNS3Guppy]

Put away the crash reports...more airliners FLY to the scene of the accident then roll to the incident on departure.

Precisely because we don't reject after V1.

Seems it's working, isn't it? Perhaps we, the professionals, know our jobs a little better than you. Could it be?

If they tell you that your brakes will work 100% of the time from a V1 RTO....I can guarantee that 5 knots faster is not some magic wall you have crossed where you go from 100% reliability to 100% failure. It doesn't work that way.

You really have no idea what you're talking about, do you?

There is nothing "magic" about being five knots faster than V1, but you do understand that V1 is not a fixed number, and has direct and critical application to a number of factors, most specifically the length of the runway in use, as well as the stopping distance available after reaching V1; you do understand this, right?

Often when we plan a takeoff, we have just enough runway to stop if we reject before V1. After V1, we do not have the runway to stop. This has nothing to do with magic. It has everything to do with the physical runway available, period, end of story.

V1 is a very, very important number, created, crafted, and calculated specifically for this takeoff, right here, right now, on this day, in this place, in this airplane, at this weight, at this temperature. It is not a magic number. It is a performance number that has very significant import with respect to our decision making process when we either reject the takeoff, or continue. Given the amount of data that goes into producing this number for this takeoff in this airplane under these conditions, what on earth makes you think you have the spice to come up with your own alternate reality on the fly? You don't; this is why we do our performance calculations before we take off. This is not mindless data; it's critical information.

So just for the record if you have the runway to stop, but are willing to fly a burning wreck through the air because you feel your brakes will fail, because your 5 kts over V1, I don't agree.

You're not a pilot, are you? If you are, you failed to grasp basic performance concepts. Unwrap your head from around the "brakes-will-fail" mentality and accept that it's far more than a braking issue.

SSG is back. Again. New name, same, stupid material.

[john_tullamarine]

but when it comes to judgment calls, where it's one bad choice vs another bad choice...then the variables for those choices come into play..the more we know the more we understand, the best we can make a good decision.

.. and that is why the discussions are so important.

Stimulating and provocative thoughts held by any individual need to be put on the table for other folk to contemplate. There needs to be vigorous discussion so that the new chums get a bit more depth than the typical ATPL course and endorsment program.

he will stop in X feet

That's not actually how it works and that was the point of my earlier comment.

Accel-stop test data is not real world (as those who have been involved with such testing would understand) and ought only to be viewed as (a little bit worse than) brick wall data for line operations.

Put it this way .. the first performance landing tests for which I was along in the aircraft caused me more than a touch of anxiety. To suggest that Joe Bloggs, line pilot, is going to reproduce the TP's performance .. is arrant nonsense and indicates a lack of familiarity with what goes on. By the time the test program is finished and TP/FTE/aerodynamicists have played with the results, the TP will be hard pressed to replicate the final averaged data.

I can guarantee that 5 knots faster is not some magic wall you have crossed where you go from 100% reliability to 100% failure. It doesn't work that way.

I am not too sure about guarantees in performance .. statistics is the name of the game and that only delves into probabilities, not guarantees. However, of course it is not a "switch on, switch off" situation. The problem, though, is that the line pilot doesn't have any real understanding as to just where the good starts to get bad ... hence the need to be mindful of SOPs.

Now maybe stalling speeds are somewhat aerodynamically absolute.....

Not really the case - one needs to define the conditions with a degree of precision to get a particular number for a given aircraft

the VMO numbers you get have a 50 kt buffer with a big g force pull back..

Vmo is a little bit different to most other limits and probably is not pertinent to this thread's discussion

if you have the runway to stop,

Therein lies the difficulty in respect of making that determination on many occasions

but are willing to fly a burning wreck through the air because you feel your brakes will fail, because your 5 kts over V1, I don't agree.

It all comes down to a question of what data and knowledge the pilot has .. considering that that pilot WILL be asked at the enquiry to justify his/her decision (assuming he/she lives to tell the tale). Methinks you are intent on needlessly dramatising the situation for effect ?

[Brian Abraham]

For those who might take issue with Johns7022's views, the importance is that such views challenge the conventions and lead to vigorous and robust discussion .. all of which should be useful for Tech Log's educational interests.

We take your point John T, but our poster johns7022 is but our old friend ssg (if it's not he's got a twin) who started the following thread and droned on endlessly about the same dreary issue, and displayed a total lack of knowledge, or acceptance of the views of the professionals, to whom this is their daily bread and butter. The ground has been well plowed, perhaps the threads could be merged.

http://www.pprune.org/tech-log/327267-would-you-abort-after-v1.html

[john_tullamarine]

poster johns7022 is but our old friend ssg

That may well be the case, Brian, but I need to be seen to be taking a middle of the road position

perhaps the threads could be merged.

.. good suggestion and only not done as the result would be a bit too hard to follow

When we eventually catch up for that beer or twenty we can discuss such things in erudite fashion ..

[galaxy flyer]

Brian and the Learned J_T,

Funny, you two should be linking to that thread. I searched last night, after midnight EST, mind you, and reread every blessed page of it. I was searching for the "formula" for estimating speed at overrun based on a decision after V1. My learned colleague from Canuckistan verified the veracity of those estimates. Also, I was reminded of the density that afflicts the gray matter at times, the knowledge exhibited herein and the patience attached thereto and the marginal increase in my own knowledge base coming from these threads. However much said gray matter hurts whilst the threads are underway.

This thread does seem endless, one expects some learning to occur, then one wakes up and realizes, "no, learning does NOT have to occur".

J_T. I look forward to shouting some of the golden nectar. Lately, I seem to be stuck visiting Pommie Land, second trip there in two weeks this weekend. Dreadful, snowy, cold and barren! And then, there are the locals!

[GlueBall]

YouTube - Airbus A340-600 Rejected Take-Off test (subtitles) (http://www.youtube.com/watch?v=hRzWp67PIMw)

[galaxy flyer]

Johns7022

On several occasions, I have been witness to large, really large, planes asked to meet the data, as calculated in that thick book known as "Flight Manual, Appendix 1, Performance Data". In each of those times, said Lockhed product performed exactly as advertised. Sitting in the jump seat at a USN Base Med, giving an eval. At a hair's breadth of V1, the plane gets whacked by birds. Absolutely, no time to discuss, it is a critical field length take-off, the pilot decides to stop. Once, at rest, the plane was on the numbers and we could not see the runway end out the front. An engineer went out to clear the turn around, after letting the brakes cool, which were near fuse plug limits. I cannot remember if any let go. Another time, on ice, at a NE base, landing calcs with RCR 6 (like Canadian friction reading), poor braking, more like poor to nil. Runway length 7000', LGW about 550K, getting evaluated. Calculated landing distance was 5000+ feet, we stopped abeam the 2,000 remaining boards, after standing, and I mean STANDING on the brakes and reversers.

My point in all this, is that the certification numbers are real, they are NOT to cast aside any "margins" or "pads" are not yours to play with. If you are on a field length limited take-off, options are scarce and the ideas being floated here are NOT appropriate for young, inexperienced aviators. I have attended the funerals of the similarly influenced, if not exact copies. Not happily, I assure you.

GF

[johns7022]

Guppy.

Pick any V1 for the day.... add 5kts faster, 5% faster, ect....isn't going to cause a brake failure on an RTO.

If you now want to change back to the subject of runway length available, and the pilot being able to make that judgment having passed V1..

Well I will yet again, repeat, yet again, that with a calculated balance field of say 5000 ft that day...on a ten thousand foot field...and say V1 is established roughly at 2000 -2500 feet...I think it's a safe bet with 7500 feet left over, and overrun beyond, Iowa cornfields beyond, that I will be able to stop the plane without TRs, without hammering the brakes.....

But again, if on that day, with 100 in-definate, blowing snow, forced to fly to the alternate, because this runway only has a GPS approach...you feel free to take the fire, bomb, broken tail up into the soup, pick up some ice...and fly off to your new runway trying to get your broken plane back down safely.

If your assertion is that you don't have any more runway..ever....that all your flights have derated balance field departures calculated into the weeds, forcing you take the emergency up into the air, all the time......that's a policy decision, not because your flying 737s into grass strips in Mongolia. Remember that the next time you fly out of LAX and derate your balanced field to somewhere in San Diego.

[galaxy flyer]

It says in my manual, at maximum brake energy (that is, an RTO using full anti-skid brakng, 33.1 million ft-lb per brake, that "Evacuate airplane, Hydraulic fire and blown fuse plugs are imminent. Leave immediate vicinity". I'd consider that a real emergency, how about you?

Please explain how a derate take-off puts the field out to San Diego or in the weeds and still complies with FAR 121 or FAR 25.

GF

Who is your recurrent training provider? The FAA would like to know.

[johns7022]

Well then Galaxy...it sounds like Boeing Products consider an RTO at the very edge of the brake and tire capabilities.....the tires are blown, the brakes are melted..run for your lives...run for the hills....

Curious if you guys have ever done a V1 RTO in the plane....all Sim work is it?

Gee whiz guys, I have done V1 cuts in jets for YEARS..over and over, and over...still here.....not so much as a flat spot on the tires.

So maybe this is a make/model problem....

[john_tullamarine]

for estimating speed at overrun based on a decision after V1

Depends on a bunch of things, as always ... however, if one considers initiating a reject a little after V1, as for example in the case of startle factor, there will be three stages to consider

(a) the speed/distance overrun. For an AEO reject this will be a modest kt/sec value and, for the OEI case, something lower again. Main result is that the speed increase will normally be comparatively modest but the distance lost which is associated with the delay can be quite significant. For example, for a nominal V1=150kt increasing to, say, 160kt, we are looking at something in the order of 260 feet/sec overrun .. 4 seconds and you have burnt up 1000 ft. As I recall for the 722, a critical reject stopping distance was in the order of 1500-2000 feet or so ? One really can't afford to squander 1000 feet in anger ..

(b) the transition from go to whoa. It is probably reasonable to presume that a well trained pilot, after the startle loss, will go through the motions more or less as per training. For the sake of the argument, let's suppose that this phase is the same for a correct/overspeed initiation.

(c) once the reject is in full swing, the rate of deceleration is quite significant and driven principally by V^2 in the first approximation. What this means, for a critical ASDR runway overrun, is that the end of the expected distance can be crossed at quite a significant speed.

(i) first result is that one IS going to end up in the rough

(ii) second result is that the braking capability is almost certainly going to be significantly less .. ie the net deceleration will decrease .. and the bird ends up some moderate distance off the end of the seal in whatever state of disrepair and in whatever terrain pertains ....

Point is ... accel stop on a critical length bit of seal ... is a VERY critical operation and one had best get it right first time around ... as there is no second chance if that doesn't happen.


Gee whiz guys, I have done V1 cuts in jets for YEARS..over and over, and over...still here.....not so much as a flat spot on the tires.

.. but not on a limiting strip length, I suspect ?

[Brian Abraham]

Who is your recurrent training provider?

More importantly, who does he fly for (if anybody - highly doubtful), just so we don't.

[johns7022]

John you have to go apples to apple....whether you abort at V1 or you abort 5 knots past...all the factors are the same...

If you want to chase down the over run argument again...then it's simple.....when you calculated balanced field and notice that you had 5000 feet left over...that tidbit of info goes into the back of your head...

If you purposefully plan out that extra 5000 feet..then again...your simply giving your self less options ON PURPOSE...which is a variable I am not willing to accept with passengers in back....by myself...sure.....

I plan for the most layers of safety, not purposefully take out all the buffers, back up systems, fudge factor and safety pillows because financial thift and corporate policy direct that I do so.

[galaxy flyer]

Johns7022

What if I told you that a derate power take-off actually increases your margins and reduces your V1? How do you feel about 3-engine take-offs and I don't mean on a tri-motor? Again, based on your plans when BFL is less than ASDR, do you calculate an accelerate-stop distance and a refusal speed, that is maximum speed on all-engine acceleration and stop and a maximum brake energy speed? An actual tire limit speed would also be a good idea, if you do these calcs. If not, how do you know your performance limits?


Now that ICAO Annex 6, as amended requiring SMS and an Operations Manual, have done a risk assessment on youre operating rules?
GF

PS: if you read my post, you would have noted it wasn't a Boeing product. But one that turns into a 28-tired, 24-braked art gum eraser when the anti-skid is functioning. Ever see an acre or two of anti-skid marks?

[galaxy flyer]

J_T

On the thread Brian referred to, a poster offered a LH "formula" that for every knot over V1 that the reject is initiated, the plane will overrun at 10 knots. That is, a 1 knot exceedence of V1 will result in a 10 knot overrun on a limiting runway. A mad scientist ran the numbers and thought that was correct in the 6-9 knot range, a greater multiple at slower speeds and a lower one at greater speeds. Works for me.

GF

[johns7022]

That makes no sense...what's a 10 knot over run? That you over run at a speed of 10kts, when you get to the end of your balanced field?

What if you have 5000 feet of buffer? Which has been my premise........oh that's right you never do...because no matter what the runway length is...your derate it right into the over run.....

So yeah, I guess, if you decide to burn up 12000 feet in your balanced field numbers...passing the 6000 ft taxi way at 32 knots...sure I get it...at the very end...if you abort past V1...you will hit the weeds a little faster..

Sure I buy that...

[galaxy flyer]

Evidently, Newtonian mechanics wasn't your forte. 1/2mv squared is a pain, the higher you speed when beginning a stop translates into greater distance to stop or a set speed when going off the end, pretty elemental.

A 10 knot overrun occurs when, after rejecting above V1 by 1 knot, apply all the braking, spoilers deployed what speed you go into the grass on a field limited runway. If you are such an aviator, you should be aware of this si ple physics problem.


The BR700 series doesn't offer derated, but flex power is available on the FMS and used when indicated.

How are those answers coming?

GF

[johns7022]

You want to talk physics...ok..and let's use Brian's numbers....

Assuming I am on my 10,000 ft field...balanced field today is 5000 feet...135 standards...not 91...when I RTO 5 knots past V1, just prior to VR.. then passed my original balanced field point of 5000 feet...at 50 knots...I now have 5000 feet to stop my aircraft that is only doing 50 knots...which might be...what? 200 feet? Nah...let's I take it easy...and not even apply brakes and let the plane coast for 5000 feet, on it's own....

I guess I will be sitting there at mid field......looking at the bomb hole in my baggage department that just took out half my controls, and reduced the structural integrity of my empenage by 99%

Oh by I forgot, I am supposed to pull the plane off...sorry...my bad...

[galaxy flyer]

The example is not a BFL 5000 feet and an ASDA of 10,000 feet, the example is BFL = ASDR, no overrun or stopway, just a cliff, down into a gorge. FAR 91 or FAR 135. no difference, the physics are the same.

How do you pass the end of BFL at 50 knots, at that point you should either be stopped (ZERO Knots) or at V2 at 35 feet, V2 better exceed 50 knots!

GF

[johns7022]

No one disputes that aborting past V1 might result in a stop past your calculated balance field length...although the argument could be made that my using TRs, better braking technique, soaking up manufacturer's fudge factor......vs the 200 hour pay to fly guy you have in your plane might result in my stopping at the end and you going into a lake of lava at the end....

But that said....if my balanced field equals the runway...a very rare condition that only lives in the world people who run derated/assumed thrust or people who routinely fly jets, heavy, in and out of short runways....

I have to tell you..that I would take my chances with a post V1 RTO if prior to rotation, if I saw some Tali-ban with an RPG a few taxi ways back, then heard an explosion in my tail......

Not an unrealistic scenario to consider, if your flying around Iraq and Afghanistan these days.....

[galaxy flyer]

No PTF pilots t my operation, it's not an airline, btw. Though I have taught a lot who have been paid to learn. You still have not understood derate power or flex power and their effects. Try this one-- why can you increase your TOGW by derating?

GF

[john_tullamarine]

That is, a 1 knot exceedence of V1 will result in a 10 knot overrun on a limiting runway

Hadn't seen that before but it is in the ball park I would expect to see - the concerns come down to the two items

(a) penalty lost distance associated with the overspeed itself

(b) gradient of the stopping part (and this is the reason that one MUST keep the anchors pushed into the floor until the aircraft lurches to a stop in the angry situation .. more than a few folk have perceived that all was well .. eased off the brakes .. and then danced into the weeds).

My view, on an ASD limiting runway is that I'd rather err on the side of continuing a couple of knots low rather than rejecting a few knots high on the historical stats.

Assuming I am on my 10,000 ft field...balanced field today is 5000 feet...

Of course your argument probably will be valid from the physics of the thing .. you have some fat to elect to reduce speed on reverse or distance and then use brakes if you were in a brake energy limit situation.

However, the Citation (as I recall you fly) is a low Vmcg, low V1 aircraft and not typical of the situation which most heavy drivers face. This is especially the case for the larger twin aisle machines. GF is talking C5A and that has the double whammy of being big iron with flea power motors.

The underlying arguments and concerns, however, are those of

(a) risk management/control (trying to stack the numbers in the pilot's favour on the day) in a rational and objective manner

(b) minimising the need for super rapid decision making with only a fraction of the story to hand at the time .. ie adhere to SOP unless the situation is pretty clear cut. Routinely winging these processes at the time has been shown to be a less than optimal approach over the years.

although the argument could be made that my using TRs

.. true but, other than in contaminated conditions, mainly a maker of noise and not much stopping value

better braking technique

.. that's a silly statement to make .. however, we would be interested in knowing what better technique you might propose compared to that used by the TP .. which will be THE best for the aircraft .. that's why the TP is employed for the purpose.

soaking up manufacturer's fudge factor

.. while there are fudge factors built into most performance data, ASD is pretty well hard data. We have, for instance, negotiated time delays (which usually are quite realistic) and the delay factor required by A/L 42 (which is not all that fat).

Just which manufacturer's fudge factors might you have been thinking of ?

[galaxy flyer]

RPG fire is not a daily occurrence, get real! Have a realistic scenario, or are there daily RPG attacks at your base? BTW, on Iraq, where there were RPG attacks, the reject criteria didnt change, just the spiral up procedure.

Why do you ignore questions that you should know, if you operate legally? Don't have answers or don't know wht you're doing? Or does baloney just reject the grinder?

GF

[john_tullamarine]

As an aside, we need to keep in mind that some of our colleagues enjoy stirring the pot a little - I have no idea whether johns7022 fits that label or not.

However, the technique does engender vigorous discussion at times and has been used to great effect by some of our more interesting members .. 411A and Milt come to mind .. both are very experienced aviators.

In Milt's case that experience incorporates a long time TP background and one wouldn't be surprised to see his participation in this thread in due course. As another aside, I have no doubt that he will be a little teary-eyed at the withdrawal of the F111 from RAAF service this month, having introduced the Type into operation so many years ago.

[BOAC]

JT - you are well aware of my standing views on 'discussions' on a thread and the contribution to safety, I'm sure. All challenges to 'tradition' are always welcome as long as they are rational, and have indeed changed 'established' procedures in the past, as with the BA 737 fatal abort at Manchester some years ago.

You will, no doubt, have a shrewd idea of identity. IF we have a 'SSG' re-incarnation we are wasting our time here

May I draw to the attention of all, from another thread:Here's my take on CRM,....from the perspective of a pilot flying a Citation Encore Single pilot...

Level 1- Captain is that a mountain up ahead?
Level 2- Captain I think that is a mountain up ahead
Level 3- Captain I think we are headed into that mountain
Level 4- Captain we will hit that mountain in 5 minutes
Level 5- Captain if you don't change course, I am calling dispatch
Level 6- Captain, dispatch says you need to avoid the mountain
Level 7- Captain, the chief pilot says you need to avoid the mountain
Level 8 - Captain, the stewardess's and passengers took a vote and think you should avoid the mountain
Level 8 - Captain, I am considering taking the controls
Level 9- Captain, I am really, really considering taking the controls
Level 10- I don't mean to hurt your feelings but I am taking the controls
Level 11- Now that I have the controls, but only have 200 hours can you confirm I am on on the right heading and will not hit anything?

from that I believe there is quite a lot he/she does not comprehend.

[galaxy flyer]

But, for better or worse, not shy about expressing opinions on that which he does not comprehend..........

GF

J_T. The "formula" on overrun speed is on about page 12 or 13 of the thread Brian Abraham linked to on the last page, this thread.

[johns7022]

Those that are taught to pour the tea, don't always know how to make it.

[john_tullamarine]

You will, no doubt, have a shrewd idea of identity.

Actually, no. We can elicit some information from the system but it is rather generic in nature. End result is that I have no idea who johns7022 might be. However, there are some stylistic similarities so he/she may well be someone else from the past ...

IF we have a 'SSG' re-incarnation we are wasting our time here

I'd take a contrary view. It has always been apparent that the best way to test one's own knowledge is to assess one's ability to express that knowledge. Thus, stimulating discussion (whomever might be the driving source) has the useful value of testing the participating readership's knowledge comfort. Folk such as SSG, and others, might be a tad irritating in some respects but that doesn't, of itself, reduce their value to the discussion.

page 12 or 13

Thanks, GF .. I'll have a looksee at the link.

Those that are taught to pour the tea, don't always know how to make it.

Good point. Knowing the makings may not be a necessary prerequisite to doing the pouring entirely satisfactorily. However, there may be some sideline issues for which the former may assist the execution of the latter.

I am reminded of a final year fluid mechanics exam question from many decades ago ... which considered the case of the PNR tea lady .. daily she would ascend the spiral iron staircase in that august building .. the question assigned one's pondering to whether she ought to stir the tea

(a) before she started up the stairs ?

(b) after she arrived at the last landing ?

(c) or, indeed, was it necessary to stir the tea at all ?

.. an interesting chap, that lecturer.

The answer, needless to say, involved a few pages of manuscript containing the usual run of the mill engineering undergraduate mathematical jiggery-pokery ...

[galaxy flyer]

J_T

It was on page 13, here's MfS' quote

Did some quick maths with some simplistic assumptions about accels and decels and that "rule of ten" is pretty good. It actually looks like it UNDERESTIMATES the runway exit speed for small values - it looks about right for 5-6 knots, for reasonable V1 values. For one or two knots, the multiple is more like 20, though. And for ten or more knots delay the factor drops to 7 or lower.

If I use the 40/70 break points for hazards, then any delay of more than, say, 4 knots is hazardous, and anything over 9 or 10 knots is catastrophic. And, as OORW astutely notes, that's assuming a relatively "friendly" overrun area...

Assuming a (lowish) takeoff T/W of, say, 0.25'g', that's an accel of about 5knots/sec. A light weight could see that nearly double. So those speed increases equate to about a second of delay.

That was in response to Clandestino in post #251, about half way down the page. Drove me near round the bend finding it!

GF

[galaxy flyer]

Does anyone here fly for an operator that includes an RPG Attack checklist in their QRH? I cannot find one in anywhere.

GF

[Clandestino]

Erm.... 10 kt overrun for each 1 kt above V1 in runway limited cases isn't actually a formula, it's more like rule of thumb. My apologies if I made it look like one. Mad (flt) scientist has pointed out correctly that actual relation is not linear yet the curve is close enough to 10 in 1 line for everyday use.

[Lord Spandex Masher]

Johns7022,

I'm curious. Do you bother calling V1 when you trundle off down the runway? If you do, why?

Also, is your view on post V1 rejects the same for contaminated runways?

When it goes bang and you look out of the window do you consider the weight of your aircraft, temperature, wind, distance to go, acceleration and runway slope in the split second before you decide to stop or go?

What was that bang? Do you consider the possibility of a tyre burst and a reduction in breaking efficiency?

What do you do on short strips where you might have a balanced field? Do you now use V1? What's V1, I aint used that for ages?!

I assume that you have flawless stereoscopic, binocular vision. Maybe Joe Bloggs hasn't so he can't rely on just his eyesight to accurately judge how much runway is left. What do you do if you have a bit of eye tension? That affects you depth perception and ability to judge distances.

Can you easily and quickly judge how much is left when you're taking off into sun with a bit of mist or haze? How about low vis, 300 meters or so? How much runway left now?

How about night? Again, depth perception is changed.

Depth or distance perception is based on previous visions of an object or scene. If you have knowledge of the size of an object from previous experience, then your brain can gauge the distance based on the size of the object on the retina. However, if you haven't seen the object previously then it is much harder for you to judge distance to it. The object, for you, would be the end of the runway. Now say the runway is narrower than your usual one, it would then appear longer and unless you'd seen that previously you are very likely to misjudge the distance to go to the end.

[galaxy flyer]

Quite agree, rule of thumb! Sorry to 'dress it up'.

GF

[galaxy flyer]

Suddenly, we have moved from a discussion on V1 and the certification criteria attached to it, to terrorism as a foreseeable event that is part of take-off planning. Are you scared to fly?

As i pointed out, at Baghdad Int'l and Balad AB, we didn't change the the reject criteria, just the departure routing and procedure. At V1, we briefed continuing--it doesn't hurt at those weights the V1 = Vr, so we were airborne anyway. But the certainty of over-rrunning out-weighed the statistically remote chances of someone shooting a IR missile; let alone the remote chance of an entirely ineffective RPG hit. If you take-off from the fictional NW International Airport, ID and someone jumps out from the pucker bush, stands up and sends you an RPG round into the tailcone of your Citation at Vr, hell, at V2, be my guest, land straight ahead. BUT, don't tell me 160,000 professional pilots with millions of safe flight hours and statistically sound procedures are WRONG for continuing at V1 with a mechanical failure.

I don't know your career background, but it is obvious you have "issues" accepting that the airlines operate without you. Yes, it is true, they do. And the thousands of captains are NOT robots who don't think every time they advance the throttles--they do--EVERYTIME! I know, I've been there. As have most of the posters on this thread and the others where you have spouted off your damaged crockery ideas. All smarter than me or you.

I fly a GLEX and use FLEX power where indicated, I fly in about 30 countries a year; including such wonders as Beirut and Afghan and Iran overflights. I don't brief RPG procedures despite nearly 30 years of military flying, it just ain't a reasonable planning factor.

What's your reject plan when a printer cartridge of C4 goes off at 50 feet AGL? At 500 feet AGL? There's a reason safety investigations END when the police determines that a criminal/terrorist event occurred--it isn't addressable within our community.

GF

I breath a sigh of relief when the EGPWS terrain display is gone and 1013 is set, especially in Lagos. V1 is too soon.

[galaxy flyer]

Please review the definition of oxymoron. And your characterization is wrong, PERIOD. And your understanding of terrorism is equally wrongheaded and based on zero experience.

GF

Beirut and Lebanon is whole lot safer and entertaining than anywhere in the NW, BTW. If the IAF doesn't bomb the runways, as happened in '06, but I left the day before. Much nicer last Fall.

[Mad (Flt) Scientist]

Lord, I think you bring up some good points...but at the end of all this...your either a thinking pilot or a robot....if you assume that all planes fly after V1, it's just hoping, upon prayers, upon assumptions, made by engineers years and years ago..that what ever happened to your plane prior to rotation will not be something that has taken out your flight controls, created a structural failure ect.

I have been patient while restricting counter arguments to dumb scenarios where the assumption is that all flights seem to work in a world where balance field calculations always seem to run up to the end of an over run, with a cliff at the end, a lava pit at the bottom. If people can't convince me that all brakes fail while performing an RTO 1 kt past V1, they are convinced that all the runways in the world magically roll up the pavement to match balanced field calculations for that day...all the while building a lake full of Great White Sharks at the end...in some silly effort to make us believe that an RTO that stops the plane 1 foot after the balanced field calculations will result, 100% of the time with a plane careening to the scene of a horrible accident.

Correct - not all runways are such that you are truly operating with ASDR=ASDA. But unless you actually do the calcs - which for a line pilot, or even an airline performance department, involves going OUTSIDE the scope of the approved data - you have no idea what actual margin you have.

Correct, not all runways have a hostile overrun area. But many do, and even a benign overrun area can cause all kinds of damage if entered at speed. Airliner undercarraiges are not designed to be offroad capable.

Correct, not all brakes fail if used from 1kt above V1. But if V1, today, happens to be set by V1mbe, NO-ONE at any OEM will guarantee that the brakes will not fail. Sure, not every chamber in the revolver has a bullet in it. How many chambers make Russian Roulette a "safe and rewarding game"?

If I look at what we do when we actually conduct the max KE brake demonstration, we have "minimum crew" - because we want to limit the number of deaths we risk. We have those crew wear fireproof suits and the like - in the hope that they might have time thereby to escape the aflame vehicle. We have airport CFR actually present, at the predicted stop point of the test, so that if it all goes pear shaped they might get the the aircraft before its engulfed in flames, and thereby rescue the test crew. And we inspect the hell out of the aircraft - especially the wheels and brakes assemblies - so that we understand exactly what kinds of risks we are running.

When you take your aircraft potentially past max KE speed and then decide to brake, you have NONE of these mitigating factors. Sure, there are some conservatisms in the flight test demo - we use worn brakes, for example. But NOT 100% worn - how worn are YOURS? Our tyres are in decent shape - are yours? All it might take is one bad tyre, that lets go early. Suddenly now you have to do the rest of the stop on just three brakes, not four. You're going to be pushing all the remaining energy into those other three brakes - probably inducing more problems. As the brakes heat they are going to fade - not fail, 'just fade'. Which means they are going to stop working as well as you'd like. But of course you can't estimate what that might mean - because the OEM data asumed you'd not be pushing the brakes so hard. Faded brakes are going to take MUCH longer to bring you to a halt - we'll find out how much longer by measuring the distance to the written off airframe, in all likelihood.

I will agree that there are some circumstances, where an aircraft will not fly, where aborting at Vr (if above V1) may be the only option. But you may well be at that point be picking - because you have no choice - a very bad second option only because the first option simply isn't available to you. I don't mind discussing the idea of what would happen for an abort outside the norms. But to pretend there is no significant risk in such an abort - that's just not helpful.

[galaxy flyer]

MfS

which for a line pilot, or even an airline performance department, involves going OUTSIDE the scope of the approved data

In my previous plane, not civil, we had charts for, and calculated on each and every take-off, the following:

Critical Field Length, Refusal Speed (accel-stop), Vmcg, corrected for crosswind and runway friction), Vmca (OEI and Two-engine Inop), Vr, Vmbe, AEO ground run, Tire Limit Speed, V2 and Flap Retract Schedule and all the calcs to compute those speeds/distances. V1 was defined as the lower of Vr, Vmbe or Refusal Speed. The handling pilot reviewed the data on a 8x10 sheet of paper and confirmed the data. Very comprehensive.

How is it the civil AFM is so limited in data for pilot use? Is the regulatory bodies afraid of pilots doing the data? This is elemental data.

GF

[johns7022]

From Madd = Correct - not all runways are such that you are truly operating with ASDR=ASDA. But unless you actually do the calcs - which for a line pilot, or even an airline performance department, involves going OUTSIDE the scope of the approved data - you have no idea what actual margin you have.


Madd - I think you figured it out.

I have never showed up to the airport and picked up the 'package' of canned flight plans, performance calcs done by dispatch, ect....

Maybe when you run the numbers ten thousand times...you start seeing things other guys don't. Actually this process started a journey of asking deeper questions about flight testing, performance planning......

A boss once said I had too much time by myself up there to 'ponder my predicament'

You know if these conversations ever get to 'go' maybe we can talk about the tough trips that had me scratching my head during planning.

[Mad (Flt) Scientist]

In my previous plane, not civil, we had charts for, and calculated on each and every take-off, the following:

Critical Field Length, Refusal Speed (accel-stop), Vmcg, corrected for crosswind and runway friction), Vmca (OEI and Two-engine Inop), Vr, Vmbe, AEO ground run, Tire Limit Speed, V2 and Flap Retract Schedule and all the calcs to compute those speeds/distances. V1 was defined as the lower of Vr, Vmbe or Refusal Speed. The handling pilot reviewed the data on a 8x10 sheet of paper and confirmed the data. Very comprehensive.

How is it the civil AFM is so limited in data for pilot use? Is the regulatory bodies afraid of pilots doing the data? This is elemental data.

Depends, at least for us, on the type and its intended use. That level of detailed data is often (I hate to say "always") provided where the aircraft is expected to be operated in an airline-like environment. But to some extent that is because we expect it to be used by the airline's perf guys, not actually by the line pilots - often they'll get the analyzed/crunched version specific to their runway today - OS, mutt, to name two, know far more about that end of things than I do.

But where we are intending the aircraft be operated in the biz jet world its common for us to provide a more simplified set of data, since the assumption is that there may not be the planning infrastructure to back up the crews, yet they may be having to deal with a much larger set of potential destinations. We've even been asked to provide that more simplified presentation for aircraft which have changed roles from airline to business operations.

It's not really a regulatory issue - we do provide that data for some cases. It's more a case of tailoring what is provided for the expected needs of each operator.

Now, in the brave new world of computerized flight manual data, one could argue it's easier to provide the more complex data to everyone. But there's still an issue of understanding the limitations in the data - if it's not really hurting your operations, simplified may be good enough.

[john_tullamarine]

Discussions of terrorists and so forth are irrelevant to the certification matters.

Let's plan on the basis of nil further such excursions into the fanciful please ?

[decurion]

To add something new to the discussion.... I noticed several comments on Flex/Assumed Temperature Method (ATM) takeoffs in relation to RTO performance. I wonder if crews know what the impact might be on the actual stopping distance during an RTO. Below is the engineering answer to this.

The accelerate-stop distance in FLEX/ATM is based on the true airspeed at the assumed temperature. This assumed distance is the basis for the takeoff performance. As the actual true airspeed (which is based on actual OAT) during takeoff is lower, the actualaccelerate-stop distance would be shorter than the assumed distance. This means, there is always some additional stopping margin when using Flex/ATM.
See: Takeoff Performance Optimization: Balancing Thrust Reduction and Stopping Margin by Dennis Ting, Meghan Nelson, and Greg Haselfeld, The Boeing Company

[john_tullamarine]

Likewise with the acceleration. The actual temperature is lower and the thrust level higher which, when added to the better stop distance, results in a degree of conservatism.

[Spendid Cruiser]

I will agree that there are some circumstances, where an aircraft will not fly, where aborting at Vr (if above V1) may be the only option.
I think everybody agrees with that. But for me the choice is about limiting the damage not thinking of avoiding it.

BTW, what makes the Citation a low V1 aircraft? I always surmised that if V1 is less than Vr then it is because the ASDR is greater than the assumed distance remaining at Vr.

[Clandestino]

My copy of Flight Crew Manual hasn't been updated for a decade, yet I think it still makes some very interesting reading: it states that western built jet transport aeroplanes made about 230 million take-offs in period 1960-1990.

There was about 76 000 RTOs in the same period.

74 of them ended in accident or incident.

2% of RTOs were initiated above 120kt and that's where the large majority of incidents came from.

58% of RTOs that ended in incident were initiated above V1

Only 24% of unsuccessful RTOs were triggered by engine related events.

According to the Airline-that-issued-FCM analysis, 55% of incidents could have been prevented by continuing the take-off, 9% by better preflight planning, 16% by correct stop techniques.

20% were unavoidable.


Well, so much for those John Wayne kind of pilots who can always make a proper and informed split-second decision, whose keen eyesight gives them ability to estimate remaining runway down to a couple of feet precision, who have an absolute pitch and immediately they hear a bang know whether it's a tyre, tires, compressor stall, engine falling off, improvised explosive device in cargo hold 3, Strela-2M taking out the No4 engine or collision with B747 wrecking the most of the aeroplane (I'm only half joking here; the survivors of Tenerife carnage described the sound of two Jumbos colliding as being similar to small bomb going off). 'Tis a pity that such a pilot has never walked the earth or is likely to ever walk it - the safety he would offer his customers would be nearly absolute.

In case you've missed the Big Briefing: the only available safety in flying is the statistical one. Perfect safety is as achievable as the absolute zero. We can only bring chances of having a mishap down to socially, politically and economically acceptable level and that's about it. However, make no mistake: bringing the aviation safety where we have it now was no mean feat, keeping it where it is won't be easy either.

I really don't see the way in which some around this forum pre-meditate the reasons that make post V1 abort justifiable to be beneficial to aviation safety. If aeroplane is unflyable past V1, only thick margins can save the day. If they were not there in the first place, tough. Fate was, is and always will be the hunter. Trick that can extend the operational life is to avoid her favorite hunting grounds and post V1 RTO is the place she certainly frequents.

[decurion]

Dear Clandestino (http://www.pprune.org/members/107081-clandestino),

Please have a look at the start of this tread. That study gives more up to date information than the Boeing study you are referring to.

[johns7022]

You guys are sunk now......

- There was about 76 000 RTOs in the same period.-

That's a lot of RTOs...that's a lot of mechanical failures, annunciator lights, problems, issues, ect that are causing the pilots to say...'not taking the plane up'

- 74 of them ended in accident or incident. -

Translated...out of ALL the RTOs... ONLY 1/10th of one percent of resulted in an accident...and that my friends, ends, all your arguments about brake failures, and planes flying off into the end into Lava Pits...done, over, your arguments are toast. One tenth of one percent is so statistically small that I could sit here and blame that on bad tires, idiot pilots, gremlins.. African operators, Pay to Fly.... but for grins let's move forward....

- 2% of RTOs were initiated above 120kt and that's where the large majority of incidents came from. -

2% = 1400 RTOs initiated above 120kts...that's fast...no one died and the plane wasn't structurally damaged.

--58% of RTOs that ended in incident were initiated above V1--

No one died, no planes banged up to un flyable status...

- Only 24% of unsuccessful RTOs were triggered by engine related events. -

You mean to tell me that 76% of the reasons why our pilot's RTOs had NOTHING To with the fire light...shocked, shocked I tell you...you mean things went bump, bang, boom...and they still stopped the plane?

- According to the Airline-that-issued-FCM analysis, 55% of incidents could have been prevented by continuing the take-off, 9% by better preflight planning, 16% by correct stop techniques. -

Sure...so out of 76000 RTOs...only 76 resulted in a plane being banged up, or an injury/death.....they think that these guys should have flown the plane at least half the time.....ok...let's look at that....76000 RTOs...and they think that half the INCIDENTS should have been flown off...ok...700 should have been flown as opposed to an INCIDENT...in other words instead of only an incident they think that 700 crews who slid off the end with no injuries or banging up the plane should have FLOWN the problem up in the air...beyond idiotic.

9% didn't preflight their planes...and 16% don't know how to stop one....not a revelation there...

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

Gentlemen...the argument is done...sticking to a position that brakes fail and post V1 RTOs will kill you is about the same as a Linotype operator railing against copy machines....

So out of all the RTOs....76000, and only 74 resulted in accidents....how many could have been avoided if the crew had more runway in front of them?

[Mad (Flt) Scientist]

Correct - only 0.1% of all RTOs resulted in an accident or incident. Sounds very safe to do an RTO.

But

To count all those low speed RTOs to justify your assertion that post-V1 RTOs are not significantly risky is not valid.

The important point is that 2% of RTOs were above 120kts (incidentally, that includes RTOs where V1 was even higher and so it was a pre-V1 RTO). Its stated that "most incidents" occurred for these cases. let's be generous to your case, and say that half of all accidents or incidents were due to that 2%.

RTO below 120kts : 74500 events, 37 accidents or incidents. Event rate, approx 0.05%

RTO above 120kts : 1500 events, 37 adverse outcomes. Event rate : 2%

You are almost 100 times more likely to end up in an accident or incident if you reject above 120kts than if you reject before 120kts. High speed RTOs are demonstrably more hazardous.

Not sure where you get the idea that none of those >120kts RTOs resulted in death or structural damage - "incident" includes "accident" in most cases.

Nothing is certain - no-one is saying (as far as I can see) "post V1 RTOs will kill you ". It all depoends on circumstances. But what is indisputable from the data is that rejections at higher speeds, and especially rejections above V1, significantly increase the risk, and as a result are only justified in truly exceptional circumstances. The default decision, justified by many years of experience, is to GO after V1. It may not be always the perfect decision - but the odds are definitely on your side taking that choice.

[johns7022]

So if an RTO has a 1/10th of one percent of banging up the aircraft... only if I don't preflight the plane, forget how to brake the aircraft, do the RTO at 120 kts or better which by the way, I don't know if I can hold down my plane at 120kts...lol....and statistically only in an airline operation that is probably purposefully using derated thrust departures....


So wouldn't it be logical...that if we were to reduce these types of accidents....we would preflight our planes? Hire or train crews that can pull the levers back and stand on the pedals...and if all else fails we give them as much runway ahead as is possible so they have the most room to stop...???

Does that seem like a stretch????

[Sciolistes]

What percentage of flights that continued with a problem at or after V1 subsequently banged up the aircraft?

[galaxy flyer]

Johns7022

Actually, what would be logical is determining why the 55% didn't continue the take-off like SOP and the record of safe flight would have indicated; that would also eliminate those who didn't use the braking procedure effectively or didn't conduct proper preflight planning as rejected takeoffs because they wouldn't have rejected. Leaving the 20% of unavoidables to fix.

Using MfS's numbers, probably half of those 37 "adverse" outcomes wouldn't have happened had the pilot simply took off. "Poor preflight planning" does not indicate they didn't do an aircraft preflight, maybe the failure point could have identified during planning. And I'll bet you won't use the brakes effectively, if under the stress of a field length limited take-off you decide to reject past V1 because you guessed it won't fly. Oh yeah, you don't do the calculations, so you won't know you are past V1. How's that feeble Citation anti-skid work, anyhow? As has been pointed out, using ATM Flex or derate power will, in most cases, increase safety margins, but you don't want to listen to anything that doesn't fit into your visceral hatred of the industry

I think we can agree Johns7022, you can fly your Citation solo in the US Northwest and let the pros fly paying passengers around world, following SOPs developed by other pros who, do performance engineering based on the work of other pros who designed and applied science to the problem of flight. They've alL posted here, with endless patience, and have vast experience in ops and the knowledge of perhaps 300 million flight hours to base their opinions on. You can fly and decide the outcomes using a "seat of the pants" approach that gave aviation it's horrible stats in the early days. The fatal accident rate has come down so dramatically due to advancing beyond your method.

GF

[johns7022]

Galaxy - 76000 Crews performed RTOs, with a 99.99% success rate of not hurting the plane or passengers.

Let's not descend into the depths of invective, please.

[safetypee]

‘johns’ (#121) is almost back to the original question … how does the industry “reduce the number of unwarranted rejected takeoffs above V1.”
The report (#1) gives several reasons for high speed RTOs, but few solutions amongst the recommendations:-
Revitalise the ‘Takeoff Safety Training Aid’; a worthy training initiative, but in the current economic climate will the likely meager effort be effective.
Surely, the critical issues can be covered in less than the current two volume tome.
Train for events other than engine failure and use realistic scenarios; focus on the limiting cases, we do not have the luxury of ‘infinite’ runways.
This is another good initiative, but similarly limited by time and resource. It would be foolhardy to expect that every relevant scenario could be covered, let alone remembered for timely recall during a real event, so perhaps we have to identify generic training, i.e. situation awareness, surprise management – issues of human performance – simplifying the decision / action process.
Understand pilot’s behaviors; yes a good research topic, but the industry has used CRM etc for many years, which in several RTO instances appears not to have helped.
Perhaps we should take what is currently known about human behaviour and re consider how it is applied.
Review procedures and guidance; yes these can influence behavior. Provide appropriately phrased SOPs, which together with education can elicit desirable behaviour – preflight ourselves as well as the aircraft. A briefing is the flight-plan for the mind. An RTO requires a new plan, formulated in a moments decision, whereas continuing after V1 is only a revision to the existing plan.
Standard situations should be reduced to ‘if – then’ decisions, providing of course that the situation is correctly identified.
The confusion surrounding ‘unable or unsafe to fly’ could be reduced by removing - disassociating these aspects from RTO training.
The basis of certification, whilst not perfect, provides sufficient assurance that the aircraft will fly and thus crews should not be overly concerned. The reasons for being unable to fly are in two broad categories.
Those which are self generated, e.g. errors in configuration, wt/cg, and weather assessment; these are generally addressed by procedures and checking (behavioural issues), and warning systems before take off.
Other, rarer events, whilst foreseeable, are so random that perhaps only a human can resolve the situation, e.g. runway incursion, double control jam, multiple engine failure. We could consider the solution of these incidents as mitigating the effects of the hazard or error, and/or reducing the severity of the impending accident. IMHO these activities, and particularly the assessment, decision, and action processes, are sufficiently different from RTOs as to place discussion and training of them elsewhere, and if the pressures of the economic climate minimize the training effort, so be it; better to concentrate on correct recognition and action for the more probable (but still infrequent) RTO / V1 Go scenarios.

[Mad (Flt) Scientist]

Galaxy - 76000 Crews performed RTOs, with a 99.99% success rate of not hurting the plane or passengers.

Translated: That's 76000 crews that think your a nut Galaxy for telling them they should have flown the problem up into the air.

Absolute garbage.

That's 76000 RTOs, the overwhelming majority of which were excuted from speeds well below anything being proposed by you. If you are going to discuss the risk inherent in a HIGH SPEED RTO you have to base the discussion on what happens when you actually do a high speed RTO - not what happens when the TOCW fires at brakes release and the "RTO" is from about 15 knots!

I'm going to try to explain the error in your "analysis" by making up some numbers, but only because I can't be bothered tracking down the actual numbers.

In the last 30 years - 1980-2010 - there have been 10 million aircraft takeoffs from the state of Florida. Of these 10 have resulted in an accident resulting in either loss of life, loss of the aircraft or both. (the actual numbers are made up - the ratio - one accident per million flights - is about right for commercial transportation.). 135 of those flights have been on the Space Shuttle.

You are attempting to argue that because a very large number of events have had "safe" outcomes, all of those events are equally safe. The statistics show that the hazard of an RTO is very much a function of the rejection speed. To ignore that is akin to claiming that the risk of the next shuttle launch resulting in disaster is approximately one in a million - ignoring all the evidence specific to the events in question, which suggest its historically more like 1 in 100.

I do risk analysis for a living, and risk analysis specific to the hazards associated with aircraft operations at that. If I were to argue, based on 76000 RTOs covering all conditions, that high speed RTOs were also equally "safe" (ignoring all the data to the contrary) and that we could happily certify our products on such a basis - well, I wouldn't be doing what I do for a living much longer.

[de facto]

When i flew in a FAR 135 carrier in the USA(single pilot), the common joke was that Citations should be renamed 'SLOWtations' :E
Maybe there lies the problem..a slow aircraft,

[galaxy flyer]

Johns7022

And 74,480, that is those rejections below 120 knots, I would have almost invariably agreed with--that speed in airliner types is high, but justified, if below V1 in the event. The remaining 1520 are, at least, questionable and in my operation would be investigated by the Standards and Safety pilots. Circumstances, training, and recommendations would be made. I know, on both civil and military positions, I have done just that for cases like this.

WRT, MfS's comments, you might spend time studying risk analysis and statistics, specifically Bayes' Theorm.

My appreciation, MfS

defacto, my 2,500 hours in it leads me to say, it is a plane for those who have thought a lot about jet piloting, but haven't the courage to try it.

GF

[johns7022]

Safetypee....your words are water to a dying man in the desert...

Mad - Based on the evidence, I can run up and down the runway, holding the nose down till well after 120kts, and have a better chance of bedding Pamela Anderson then putting more then a little mud on the tires at the end.

Cling to brake failures and RTOs being deadly and anything after V1 is 'danger danger Will Robinson' but the statistics don't bear it out.

The only thing that bears out is that if the crews, aborting at whatever speed they abort, had more runway...they would not have blown the tires, and put the mud into the gear..

You want to reduce RTO issues...stop assumed thrust / derated departures...give the crews more runway to work with...

[galaxy flyer]

The statistics say nothing of the sort, they show that RTOs at high speeds, especially beyond V1, are at least, 100 times more hazardous than those at low speeds. That is not the same as saying here is NO hazard at low speeds. Try a reject at V1 in a Citation at Newport, RI (2,990' and I've been there in one) and you will go off the end. Just like you would rejecting 10 knots past V1 departing KDOV at gross weight with a rotate increase speeds. That's overspeed V2 for you Airbus types.

[galaxy flyer]

Did you go off a runway on a flex power take-off and get the sack? As things stand right now, what airlines do have ZERO effect on you, so why the horror at them. Especially since they are, in fact, safer.

GF

[john_tullamarine]

We appear to be getting to the going around in circles stage. I'll leave it go for the time being but if we don't see some further development, it might be better to retire the thread ?

[johns7022]

So out of 76000 RTOs, 2% initiated at above 120kts...well past V1...let's stick with those..

2% x 76000 Total RTOs = 1520 High Speed RTOs

How many accidents? 74 = Less then one percent...or .05 percent.

So 99.95% of the High Speed RTOs resulted in No banged up Planes, and No loss of life..

And if we want to play with the numbers....let's talk about the .05 percent....how many of those were off shore...guys that couldn't run the numbers, pay to fly, new guys, crappy runways, junk equipment....????

And if that .05 percent had miles of runway ahead of them...do you think they would have flipped the planes over going straight forward? Do you think the plane explodes when the tires hit 130 kts? Do you think maybe they ran out of runway?
How many were over gross? How many flying Derate?

[SNS3Guppy]

Guppy.

Pick any V1 for the day.... add 5kts faster, 5% faster, ect....isn't going to cause a brake failure on an RTO.

Irrelevant.

I use a 10,000' runway, and see a stop margin (that's what's remaining after rejecting the takeoff at V1, by the way) of several hundred feet...assuming everything goes well, assuming the airplane does what it's projected to do, assuming that it can match the performance that the test airplane had on a perfect day with a test pilot at the controls, with new brakes, yada, yada, yada.

Assuming that the takeoff is rejected at or before V1. After V1? Those piddly few feet of stop margin are gone in a flash, and the stopping distance is considerably larger.

One is MUCH, MUCH safer going airborne, and coming back to land with a plan, with a full, vacant runway ahead, and with rescue services (as required) ready and briefed.

High-speed rejected takeoffs (after V1) tend to result in aircraft damage, loss of control, and put the airplane in exactly the wrong place for coming to a stop: at the end of the takeoff roll.

V1 is the point at which the decision time is over. One is now going flying. Unless something utterly catastrophic occurs which entirely prevents the airplane from flying, then one is far safer to go airborne, and sort it out on the way back to the full length of the runway.

Apparently everyone understands this but you. Then again, we all know why.

[Mad (Flt) Scientist]

So out of 76000 RTOs, 2% initiated at above 120kts...well past V1...let's stick with those..

2% x 76000 Total RTOs = 1520 High Speed RTOs

How many accidents? 74 = Less then one percent...or .05 percent.


Well, in fact, 74 out of 1520 is just under FIVE PERCENT. 1 in 20. Do you think a 1 in 20 risk of an accident/incident is a good basis for decision making?

Even 1 in 2000 - your erroneous value - is an unacceptable risk given that the expected/target accident rate is 1 per million. Anything which will cause a perceptible adverse change to that 1 in a million rate is a bad thing.

I'm going to go back to the 'Russian Roulette' analogy:

If I have a confirmed empty revolver, checked by myself and a trusted friend, then I can play Russian Roulette 'safely'. There remains the risk that my friend is secretly a psychopath, but on the whole it's safe. That's rejection before v1. Unless something exceptional occurs, it should be safe.

If I have a revolver picked randomly and handed to me by a stranger, to place it to my temple and pull the trigger is foolhardy, unless I am coerced to do so. That's rejection above V1 when I don't know what my margins are. Maybe all the chambers are empty and I'll get away with it. But maybe not. (Coercion = 'plane will not fly' by the way)

Even if I 'know' there is only one bullet in the chamber - analagous to understanding some of the margins for RTO above V1 - it's still a significantly elevanted risk. The risk of not playing/not going flying has to be very high for me to take the chance.

[A37575]

High-speed rejected takeoffs (after V1) tend to result in aircraft damage, loss of control, and put the airplane in exactly the wrong place for coming to a stop: at the end of the takeoff roll.

Never a truer word. A couple of short stories that might interest readers. During type rating training on the 737-200 simulator with brand new 200 hour graduates, we were practicing rejected take off procedure on a performance limiting runway. In other words if everything went as planned from an flame-out about 10 knots below V1, the student would stop within 100 metres or so before the end. We must have conducted ten of these within 15 minutes just to get the right sequence of actions. Both students were lightning quick on the actions - after all there was no stress because it was a training session; not testing.

In the majority of the rejected take off's, one student would consistently go off the end of the runway by 100 metres or so. Yet his actions were fast and accurate same as the other chap who pulled up OK.

From my position on the jump seat, by chance I turned around to look at the instructor panel screen as the student who was over-running, accelerated down the runway through 70 knots or so. I suddenly noticed that the indicated brake hydraulic pressure at the rudder pedals was not zero as it should have been, but oscillating rapidly between zero and around 500 psi during the length of the take of roll. This indicated the pilot must have been inadvertently riding the brake pedals on the roll. In the darkness of the simulator it was not possible to see exactly where his toes were on the rudder pedals.

The slower acceleration to V1 nullified the planned decision speed to the extent that, even the 10 knots below V1 chosen for the flameout, didn't make up for the slow acceleration.

This explained why he constantly over-ran after aborting - despite correct actions. When this was pointed out to him, he vehemently denied he had his feet up on the brakes during the take off. I think there was a culture aspect with loss of face which is why he refused to accept the obvious.

There had to be a way to convince him; since if he did this in real life, one day he was going to be in real trouble. Hot brakes for one.

So I asked his PNF (same country of birth) to sit at the instructor panel and observe for himself the brake pressure readings for each wheels. Sure enough, as the simulator went down the runway the little red indicators showing pressure at the brake pedals, bobbed up and down signifying partial brake being applied by the student. I then asked them to discuss this between themselves in their own language. Eventually there was an understanding nod of the head of the culprit when his mate explained what he had personally seen. After that he had no problems with the rejected take off's.

On a separate occasion in a real 737-200, the crew noticed the occasional flashing of the wing body overheat light while taxiing for take off. The runway was short (5400 ft) and the over-run area deadly with a cliff 20 yards from the end of the actual runway. The captain lined up and by now the wing body overheat light had extinguished. He briefed his F/O (who had just 500 hours total time) that below 80 knots he would abort for any Master Caution indication and after 80 knots he would keep on going except of course for anything serious like engine failure.

The 737 was runway limited that day and V1 was around 128 knots. At 10 knots below V1, the Master Caution light came on caused by illumination of the wing body overheat light. The captain instantly aborted, but in his haste initially forgot to select manual speed brake for a few seconds. With full braking and full reverse he was able to stop the 737 with the nose wheel right on the very end of the runway. It was a very close thing.

During the taxi back to the terminal, the F/O asked why had the captain aborted contrary to his briefing. The captain was honest and said he could not explain his change of decision but that it was an instantaneous reaction to the sudden appearance of a large amber Master caution light in front of him. One could easily criticise the captain's potentially disastrous action -especially his initial failure to extend the spoilers. But that is not the point of the story.

Both events of the dragging brakes student and the high speed abort just mentioned, are typical where incorrect pilot actions at a critical time on the take off roll and leading to a high speed abort, can increase the dangers of high speed aborts on a limiting length runway.

In the case of the brake dragging mistake, the V1 was compromised. Because of the inevitable momentary indecision that a crew will experience if something out of the ordinary happens when fast approaching V1, this writer is convinced that it is a much safer bet to keep on going than risk a stuffed-up late abort.

[mutt]

Does anyone here fly for an operator that includes an RPG Attack checklist in their QRH? I cannot find one in anywhere. Actually we do :):):)

a very rare condition that only lives in the world people who run derated/assumed thrust or people who routinely fly jets, heavy, in and out of short runways.... Not rare at all, even on a 10,000 ft runway with no Derate/Flex, we routinely operate 747's that are limited by the 115% all engine capabilities. When you also consider that they have steel brakes, there is NO WAY that they are stopping on the runway if they consider V1 to be a DECISION SPEED rather than an ACTION SPEED, if they overrun one of our least favorite runways, the drainage ditch will rapidly remove the undercarriage.

Your argument may be valid on light jets operating on long runways, but in an airline environment, forget it.

As for the statistics regarding RTO's between 1960-1990, ask yourself what type of aircraft were operating in that era, what was the level of technology.

Finally, just admit that you are SSG come back to haunt us.......

Mutt

[johns7022]

I am sorry...your right Mad...5%......5% of the high speed RTOs had accidents..

Again how many were off shore, bad pilots, short runways, guys running derate, guys that couldn't brake, over gross, ect ect ect..

I'll take my chances, with a high speed RTO, just based on statistics alone in that I don't fly over gross, I can pull the levers back and step on the pedals...I do the flight planning and thus have a clue where my balanced field shakes out against runway length...

Do what you guys want...fly the emergency up in the air, because you painted yourselves into the corner with an assumed thrust departure...honestly I don't care...congress doesn't care, the public doesn't care, the FAA doesn't care...

All I can do is run my flight dept the right way..

Still here, I still remain.

[galaxy flyer]

Who was it that said, "some men trip over the truth, brush themselves off and continue as if nothing happened"

You can do as you please, just as long as it doesn't involve public transport, you are still wrong. As a Citation operator (contractor, perhaps?), your boss most likely doesn't have a clue as to the dangers to which you are exposing him. I doubt very much any training organization worthy of the name would teach these RTO procedures. You'll be on your own should the far end of the runway reaches out smites thee.

The scary part is, so far, you have not presented any clear, understandable means of verifying the aircraft's runway performance as to accelerate-stop distance, NONE, NADA, ZILCH. Please tell me you, at least, use some performance data to back up your guesses.

Do you hold off in retracting the gear until the runway is behind you so you can land it, if an engine should fail, too?

Mutt. Do you really have a checklist for that? I fly there often enough to be interested in knowing more.

GF

[johns7022]

What I love about these forums is some poster's position that they are speaking for a whole industry of professionals. Like they are part of the club....

I would love to fill up a room full of the 1500 crews that did a High Speed Rejected take off, and are here to talk about it...passengers are here to talk about it....and have some our very experienced and knowledgeable forum trolls tell these guys in person that under their specific circumstances, despite everyone walking away...there were wrong.

Some of you can only exist in a world where Darwinism doesn't exist, where credentials can't be checked, where anyone with a mouth and a keyboard has an opinion.

[galaxy flyer]

Only if we can bring in the families of the dead and get their opinions of captains that failed to follow procedures based on factual evidence and killed their kith and kin by rejecting the take-off at high speed. Did you read the CRJ overrun accident at KCRW? I suggest you do, I just briefed it to my pilots. The statistical evidence is clear--high speed aborts are hazardous and aborts past V1 are lethal.

What if they crowd of 1520 survivors were told that the failings of their crews exposed them to unwarranted danger, that they would have been, statistically, safer NOT stopping.

GF

[SinglePilotCaptain]

I think it's been said before...

A rolling aircraft does not guaranty a flying one.

With 5000 feet of balanced field, on a ten thousand foot runway....only an idiot takes an abnormal and turns it into an emergency by taking the problem up in the air.

I certainly won't apologize for my corporate brethren who have made mistakes as colossal and idiotic as the airline guys. I find it silly you hang on to some philosophy that your in some lifeboat with the other guys....they won't be there when the fire light comes on.

[galaxy flyer]

Oops, headin' for the rhubarb with SSG V2.1 aka SinglePilotCaptain......what idiocies in the future?

GF

[Brian Abraham]

Ya gotta admit GF he provides a comedy routine that Sienfeld would be envious of. Was wondering how long it would take before he started talking to himself, sure sign that ssg still ails.

[Lord Spandex Masher]

Johns

Lets say, hypothetically of course, that you were operating as part of a two man crew with...mmmm lets say Single Pilot Craptain in the RHS as handling pilot and you heard a bang, possibly a loss of oil on a PT6 (or something) at V1. SPC announces continue.

What do you do now?

[johns7022]

Lord I fly single pilot...give me the scenario in full..be specific and I will be happy to hash it out with you.(Plane make and model, how many people, runway length, weight, ect).

[Lord Spandex Masher]

I did say hypothetically.

Galaxy - 76000 Crews performed RTOs, with a 99.99% success rate of not hurting the plane or passengers.

You didn't appear to be too concerned about the specifics, make or model when you thought the statistics were on your side.

Just curious what you'd do.

[johns7022]

So I will consider your post a non starter then...

The RTO numbers came from the airlines.....which I don't fly for, but since all the airline fly boy apologists seem to come here to die, I have no problem using their numbers...

You wanna talk specifics...then lay them out...don't post then dodge...it shows a lack of character....

[Lord Spandex Masher]

No I don't want to talk specifics. I want to know your actions should somebody, you may one day be flying with, elect to continue after V1.

You don't like dodging then answer the question.

[johns7022]

Lord I suspect my Pomeranian here has more time in turbine aircraft then you do.

[Brian Abraham]

Lord I suspect my Pomeranian here has more time in turbine aircraft then you do. And he probably has more than you because we know you ain't got none.

[galaxy flyer]

Could this be our friend--Johns7022? (http://newssun.suntimes.com/news/2716160-418/video-hanson-lake-family-county.html) Just sayin', shows up suddenly, posts many outrageous posts and flies a Citation Encore.

A Round Lake man who was chief pilot for Family Video, a national DVD and video game chain with a number of stores in Lake County, allegedly faked aviation fuel receipts for flying executives across the country, and used the nearly $500,000 for gifts and vacations.

Hmmmmmmm............

[johns7022]

Insults are the last resort or of those who depth have been drained of logic....

It's obvious I am right...it's all coming down to trolls, insults, figuring out ways to get me banned...I'm keeping it civil.

[galaxy flyer]

Amongst the professionals pilots and engineers here, you have made yourself a laughingstock with any help from others. Ignore list, for sure

GF

[johns7022]

Wonderfull Galaxy...I suggest you load up a plane with all the other experts....do some calcs...find a balanced field of say...5000 feet..and roll up and down Kabul International all day...and remember....always Pull Up at V1.

Because no matter what ALL PLANES FLY AFTER V1

Yes siree...you heard it right here on PPRUNE...that once you get V1...it's smooth sailing boys..the plane will fly...you betcha.

[Lord Spandex Masher]

You still won't or can't answer my question.

[Brian Abraham]

LSM, apologies from the rest of the proon membership, but waiting for an answer from this dill is akin to waiting for hell to freeze over. Basically he is unable to answer because he has not the level of knowledge to understand the question. But I think you have already figured that out. As GF suggests put him on your ignore list. The only reason I haven't is I find his moronic posts entertaining, in as much how somebody could think they could hoodwink known professionals. Can't even talk the talk, let alone walk the walk.

[Lord Spandex Masher]

Insults are the last resort or of those who depth have been drained of logic....
Lord I suspect my Pomeranian here has more time in turbine aircraft then you do.

John, says it all really. Still, I'm curious what you would do if someone wanted to continue at or after V1.

Brian, no need to apologise, I feel the same way.

[johns7022]

I wouldn't apologize for Brian I am sure he has found the Darwinian inevitable answer to his place in aviation.

As far as what I would do, if someone continued after V1..

By continue you mean? and if it was someone else...what do I care.?

[Lord Spandex Masher]

By continue I mean, well, continue, carry on, go, not stop etc..

If you go back to my original question which I posed hypothetically you will be able to work out why you would care.

I am curious about what you would do, hypothetically, if you were, hypothetically, part of a two man crew and the other pilot wanted to continue after you heard a big bang at or above V1, hypothetically.

[mutt]

You continuously talk about a required takeoff length of 5000 on a 10,000 ft runway, but what if the runway was 8000 ft or even 6000 feet, what is your concept of an acceptable margin? Would you consider "putting it down again after VLOF"? Also considering that you are here to educate us, kindly tell us WHAT VERSION of FAR 25.109 your last aircraft was certified under.

We employ 1500 pilots...... EVERY LAST one of them is trained to GO AT V1.... and I'm not just talking about airline flights, but the highest level of VVIP. So are they all wrong ?

Finally, apart from 1, all of our corporate aircraft have the ability to use FLEX/REDUCED THRUST... so it appears that even corporate aircraft/engine manufacturers don't agree with you.

GF..... they have some interesting items installed that require a checklist :)

Mutt

[johns7022]

Lord.......when I fly with other people, as a general rule...99.99% of the time...I am either PIC with a passenger up front....or as an instructor with a student...I did the performance planning...and thus I will make the call to roll it out, or fly it off....

But during the times where I have flown SIC in say a GIV or Astra...planes I wasn't trained on, I was at the mercy of the captain's decisions......to a point.....

Now oddly enough on one trip in the GIV going into LA, in a jet I had maybe, 2 hours in, SIC, Not having gone to school.....the captain got too close to a SW 737 on a visual approach....ATC warned of this....I pointed out the N NUMBERS on the jumbo jet in front to the pilot......

When the wake turbulence hit...THREE TIMES...the GIV wings went almost 90 degrees vertical..at about 45 degrees I looked at a catatonic captain...

So I pushed the yoke forward, applied enough counteracting control forces to keep the plane from flipping over....3 Times.

Of course the captain blamed it all on ATC...

So to answer your question...more directly...when flying with someone...I have no problem 'Helping' the captain make the right decision.....and taking positive control if I have to.

If that GIV was an 'Airline' hypothetically...there would have been no time for CRM, Graded Assertiveness, and little chance that an inexperienced FO would have done anything, nor recognized what to do in time to address the problem to the captain, have positive transfer of controls, ect.

I doubt you can roll a GIV at 4000 feet, at such a slow approach speed and come out of it...

[mutt]

If that GIV was an 'Airline' hypothetically. If it was an airline operated Gulfstream IV, they wouldn't have had you in the right seat in the first place :):)

BTW, when you played around in that aircraft, did you happen to see that the FMS calculated REDUCED TAKEOFF THRUST??

Mutt

[Lord Spandex Masher]

So to answer your question...more directly...when flying with someone...I have no problem 'Helping' the captain make the right decision.....and taking positive control if I have to.

As interesting and impressive as your tales of derring-do are I still want to know what you'd do.

Maybe if I give you some options:

Ok, V1, big bang, your natural reaction is to stop, PF says go - do you:

- Take control and try to stop.
- Go against what you think is the correct course of action and allow yourself to continue.

[johns7022]

Lord....V1...bang...like an explosion?...I would pull the levers, take the yoke and let the plane roll out.

No I won't let the PIC kill me.

If your chasing the the 'wrestling the controls' argument....having been a flight instructor long enough...anyone I have flown with has a pretty good idea that by the time I grab the controls...the controls needed grabbing. It won't be an argument...if in some alternate universe, the PIC wanted me fired, after saving the plane/passengers...we can take that up with the boss....and he can decide if the PIC was right by trying to fly a broken plane...or I was right in creating a 'Non event'.

Since I fly corporate...this type of scenario. where I have to take control....played out in more times then I care to admit...simply leads to nothing more then my not flying with this guy again...either in my plane or his...

Everyone is alive, that's what counts.


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

Mutt - Maybe before we start with what the ops are used for your organization...we can start with the hiring profile of your pilots...what type of aircraft you fly...how many incidents you have...and if in the end...if you have problems...and or your pilots are so green as to not wanting them to make a decision....then you give them nice simple non thinking solutions, and just hope that the scenario they face, will be solved by a one size fits all approach...

Honestly Mutt, if had a bunch of 200 hour pilots flying my planes....my pending heart attack and ulcers aside, I guess the best I could do is just have then fly by the numbers and hope they never run into wake turbulence, ice, wind shear, multiple problems, terrorists, jack screw problems, a fire after V1, a rudder problem, flying a plane with a composite tail.......ect ect....

As far as acceptable margin to stop a plane...in what I fly...I can and do land on 3500 ft strips..

So if I calculate a balanced field of say 5000 ft...typical day...and the field is 8000ft...then it's pretty easy to figure V1 would be roughly at 2500-3000 ft down the runway...that leaves...5000 ft, pre VR...that's pretty darn easy....

The real issue isn't just how much runway ahead but the conditions I would be pulling the broken plane into..

Taking a problem up into the soup, on a SID, in the mountains, picking up ICE, trying to get back down to minimums...as opposed to a nice easy roll out is a no brainer for me.

As far as acceptable margin...every runway is different, and weather conditions are different...it's not hard to calculate runway needed to stop...on a post V1 abort...that's easy...the real question is what's beyond the end of the runway....cliff, lava...over run, miles of flat Iowa cornfields...or just miles of nice flat dry runway...

[mutt]

Forget the stories of 'daring do' and answer the question, what is your acceptable margin of additional required runway in order for you to abort above V1.

Mutt

[Lord Spandex Masher]

it's not hard to calculate runway needed to stop...on a post V1 abort...that's easy...

Really? Got any examples? You never know your knowledge might save lives one day.

I'd appreciate examples for:

V1+5kts, +10kts, +20kts, +30kts.

When do you do these calculations? Pre-departure or during the take off roll?

[galaxy flyer]

Johns7022

You fly a G-IV for an operator that lets pilots with NO type training act as a SIC? Leaving alone the fantastical idea that it's you being selected, what would the insurers or passengers say at that breathtaking bit of irresponsibility? At what distance can you read N numbers? I doubt it could be more 1,000 feet, so you didn't get that close, I know that. How did the SW B737 suddenly become a "jumbo jet"? If this was KLAX, how did ATC clear a visual and let your plane close that close? You can BS the fans, but you cannot BS the players. Here, we are all players.

Mutt. Ah yes, we some, no doubt cruder, versions of that kit, too.

GF

[Lord Spandex Masher]

Asking me if I can or can't do something isn't teaching. What I can and can't do is irrelevant. If it's so easy to calculate post V1 abort performance why does it matter what is past the DER?

Can you show us some examples or not?

[galaxy flyer]

Again, what range can N numbers be read? They are, by FAA standard, 12 inches high; are you telling me you can read something the height of a laptop at 1,000 feet. I doubt that ver much. I live in FAA and ICAO world, no competent operator of Gulfstream-class planes does the minimum under FAR 61 for training. All of our pilots have a full type rating or they don't fly, as required crew. Internationally, everyone must have a type rating.

I have not heard of an "open pilot waiver", but I do know of FAR 61.55 SIC qualification.

Still, I'd like to see how you calculate accelerate- stop distances.

GF

[mutt]

So I pushed the yoke forward, applied enough counteracting control forces to keep the plane from flipping over....3 Times.
So who performed the Go-Around?

We operate about 150 aircraft ranging from 16,700 lbs to 870,000 lbs with some crews who initially trained on DC-3's, none of them are employed with 200 hrs. I know exactly how many engine failures we have had in the last 10 years, how many high speed aborts, how many incidents, how many overruns. We operate aircraft built by 7 aircraft manufacturers, and train crews in about 5 different countries.......... So i guess that we have enough experience to decide that YOU DON'T ABORT AFTER V1........

So did you do a reduced thrust takeoff in that G4?

Mutt

[Lord Spandex Masher]

You haven't given us any examples of post V1 perf. calcs.

[galaxy flyer]

Johns7022

You are the one here proposing new,"improved" performance planning, do show us professional engineers and pilots how you do it. I would be especially interested in how you use landing charts to calculate safe ASDR on a post-V1 reject. An unknown technique prior to 2100Z today
GF

[safetypee]

JT – moderator; appreciating your forbearance with aspects of this thread, it is unfortunate that the original theme has been disrupted by less relevant discussions. May I suggest that the thread be split, that the latter discussions be removed elsewhere so that a more meaningful exploration of the original subject might continue to be explored?

This request is not intended to stifle a broad range of views. We all seek ‘truth’ and require open minds lest we are mistaken, but unfortunately it is difficult to debate currently accepted ‘science’ truths relating to post V1 RTOs without rational and logical presentation of alternatives.
I’m very interested in the ‘aside’ discussions as they provide insight to aspects of human thought, behavior, needs, belief, etc; possibly relating to problems of pilot training and progression of corporate pilots into commercial operations.

In other threads, some protagonists (including johns) express views that they are overlooked when seeking commercial positions, and that ‘cheaper’ and less experience first officers are being hired instead.
The corporate experience indicated in this thread is not as required by the airlines (nor the industry). This experience is not flying hours, but consists of personal qualities, airmanship, and human interaction which contribute to ‘attitude’. I recall that many airlines hire for attitude and train aptitude. I doubt that they would hire a pilot exhibiting a ‘know it all’, self centered view of operations, particularly if they could not explain opinions which differ from the accepted norm.

With respect to the thread subject, the distracting discussion could cause us question that deep and often intuitive beliefs of ‘us ground abiding humans’ might be hidden in our subconscious, only to surface in stressful situations - RTO assessments at high speed. However, this would only be another cause for RTOs after V1, suggesting that current training suppresses this innate behavior.

One argument is that we are approaching the limit of human performance and thus for high speed RTOs there should be greater margins of safety (not necessarily as expounded previously). Technology has and still continues to improve reliability, thus the human in comparison appears the weaker link. Human behavior can be improved, but not always dependably in increasingly complex operations.
Some might call for automation, which is by no means as dependable or flexible as the human, or do we persevere with the human in times of economic hardship, including a reducing source of ‘experienced’ pilots and fewer opportunities to gain experience, and even perhaps a diminishing passion for flying vs just a job; but again these are problems not solutions.

[Lord Spandex Masher]

I've got a type, several in fact.

The real issue isn't just how much runway ahead but the conditions I would be pulling the broken plane into.

Taking a problem up into the soup, on a SID, in the mountains, picking up ICE, trying to get back down to minimums...as opposed to a nice easy roll out is a no brainer for me.

As far as acceptable margin...every runway is different, and weather conditions are different...it's not hard to calculate runway needed to stop...on a post V1 abort...that's easy...the real question is what's beyond the end of the runway....cliff, lava...over run, miles of flat Iowa cornfields...or just miles of nice flat dry runway...

I still want to know how you easily calculate runway required on a post V1 stop. You haven't answered because you can't.

I still want to know the reason that you will stop after V1.
Is it the weather conditions?
Or flying a SID?
Or icing?
Or flying an approach to minimums?
Is it what's beyond the DER? Does that matter if you're calcs are so good and easy to do?

All of those things we are trained to do in an aircraft designed and certified to do it.

[johns7022]

Tell you what Lord..it's a slow night....

You load up a Citation 560, 9000 ft field, 1000 MSL...fly from PDX to DAL, full pax, call it ten peeps at 210 each, 35 lbs of bags each...

Plan the trip, come back with the numbers, show me you can plan a flight..then we will talk departure numbers...ok?

[galaxy flyer]

Show me a 10 passenger C560, first! Second, assuming you meant 8 passengers and 2 crew, your load exceeds ZFW by, at least, 150 pounds in an XLS+, more in an Excel. Third, the PDX 7 departure has a min climb gradient of 350 ft/nm or greater and numerous close-in obstacles, do you have a runway analysis provider? Fourth, the Excel cannot do this trip, probably in either direction, with your fictional payload. Any other bright ideas? I could do it in GLEX without even trying.

I've answered your BS questions, now answer one simple, do you calculate accel-stop distance on each take-off to justify a decision to reject after V1?

GF

[galaxy flyer]

If you are going to put a passenger on the dark, belted potty for 3+25, eastbound, and with a stop 5+00 westbound, be my guest. I don't do that, don't plan that way, either. Cessna says 8 seats plus a belted potty for a total of 9 passengers; add in the crew for a total of 11. Where are you getting 13? And the ZFW restriction means it doesn't matter what you say for seating, you reach ZFW FIRST!

It would be nice, if you knew what you were talking about.

GF

BTW, J_T, I think this thread is getting far off track--in fact, so far, it is out of HF range.

[Brian Abraham]

I wouldn't apologize for Brian I am sure he has found the Darwinian inevitable answer to his place in aviation.Yep, and a very satisfying career it was too, working with professionals, which if you ever get to learn to fly you may have a crack at as well, though I doubt anyone would take you on because of personality issues.

[galaxy flyer]

How come the XLS has a ZFW of 15,100 pounds and you quote 12,200? Which one is a CE 560, an Encore or an Ultra? And how come Cessna's website shows both models as not being single pilot qual'd? My single pilot jet time is all tac fighter, btw, with a seat to solve all problems!

Gee, I thought 13 was about 4 too many in GLEX. I never flew the CE560, so knave learned that their website doesn't show all the possible interior arrangements. So, if an operator is stupid enough, he can put 10 valued employees in your careless hands. Being solo, I presume you wear an O2 mask above FL 350. No, not really, you don't follow any other reasonable regulations or good practices like climb gradients, the history of rejected take-offs, why that one.

Good luck, hope you don't make headlines!

GF

[Brian Abraham]

13 max seats possible..
Two in Front, double club in back, remove potty for three pax seat in back.
Our config is two up front, double club, with potty. That's eleven...I said ten. I fly single pilot. Bull****e. No you don't, cause the aircraft ain't certified SP. You don't fly nothin.

[mutt]

As you are talking about the Cessna Citation 560, Encore/Ultra.... please have a look at....
Performance (http://www.cessna.com/citation/encore/encore-performance.html)

It's worth noting that this is the latest in this family.... also note the following.." Single Pilot Certified No".... (but this doesnt apply to the older versions)

Now if you are talking about a different aircraft, please let us know.

Mutt

[mutt]

There is no issue about flying the small Citation single pilot..... but look at the performance figures that are given for the Ultra ++. They don't appear to agree that you can operate PDX-DAL with 10 passengers.... I would presume that the performance of the older Citation 560s would be even less.


Mutt

[johns7022]

Worked for me when I ran it tonight... :)

Tell you what...I won't wander into your make and model if you don't wander into mine...ok?

[mutt]

Look at the performance chart from Cessna, it shows Max Payload for the Citation 560 Ultra ++ at about 2,350 lbs, not your required 2,500 lbs. With this payload you can carry the max payload about 1180 nms in nil wind conditions. The distance from PDX-DAL is 1493 nms which today happens to be 1280 nms with a 75 kt tailwind (Jetplan data). That gives you about a 2000 lb payload. So how are you getting 2500 lbs?

No alternate? No reserve? What?

Mutt

[SNS3Guppy]

As I sit back with popcorn and chuckle, for those too ignorant to know, you're trying to match whits with a professional performance engineer (Mutt) who quite possibly knows more at this stage on the subject and is far more conversant about performance, safety, and requirements, than some of those arguing with him ever will be in their sorry lifetimes.

You guys sure know how to pick 'em. I wouldn't argue with Mutt regarding performance, because I know from the outset, I'd lose. Some of you are simply too stupid to understand that, so have fun beating your head against the wall.

Personally I'll have fun watching Galaxy Flyer and Mutt wipe the floor with you, when they're done. (Not that they haven't, already...)

[galaxy flyer]

Like I said earlier, never argue with an idiot, they drag you down to their level, then beat you with experience.

Cessna has certainly messed things up with designations--two different planes, the old Citation 5, improved is a CE 560; as is a Citation XLS with an entirely different fuselage and engines. And 28 years since I last flew one, I can attend recurrent and and fly any of them. The TCDS is complicated to go through as any.

Just to clarify things, we are a private operator, we have a customized runway analysis for each take-off and remain within it's limits; we have a comprehensive ops manual and a SMS program. We try to operate to FAR 121 standards, to the extent of doing 3 page airport surveys before operating into a Cat B or Cat C field. I'd like to think other private operators are a conscientious about their operations, as we do not what to put others at risk.

Mutt. Better than that, he probably says he can do a non-stop return!


This thread has strayed far from a V1 discussion.

[johns7022]

Mutt..I gave you my BEW and ZFW.

12200 ZFW - 9645 BEW = 2555 ZFW Payload

Based on last night winds..and some creative use of choosing certain power settings and the optimum alts....the trip was more then doable, considering all the places to stop between PDX and DAL....if the winds changed I probably would have stopped in Colo somewhere.

If your doing this on paper...shoot yourself now...your not going to be able to sit there, moving alts/power settings around to find and optimum combination that will keep you legal for take off, and have a legal reserve on the other end. Not in this lifetime that is.

[GlueBall]

"...Technology has and still continues to improve reliability, thus the human in comparison appears the weaker link."

. . . tell that to the Quantas A380 pilots at SIN who had experienced 50+ ECAM messages, many contradictory; Engines 1+4 operating in "degraded mode;" Buses 1+2 dead; APU wouldn't take up electrical load; pneumatic leaks in left wing; fuel leak in left wing; failed fuel-dump system; No.1 engine couldn't be shut down after landing and continued to run for 4 hours...! :ooh:

[safetypee]

GB, “Technology has and still continues to improve reliability, …”
Perhaps of interest / relevance in this thread, is that Trent engine did not go ‘bang’ during takeoff, often assumed to be the most critical period.
“The human in comparison appears the weaker link." - Context. An essential component of awareness and understanding the problem, which I assume you already know … ;)
This does not detract from the excellent talent and skills of the crew, which IMHO argues strongly for the human to remain in the loop during critical tasks. We Still Need Exceptional People. (http://www.flightsafety.org/asw/mar09/asw_mar09_p53-56.pdf)

However, humans do have limitations, especially in high stress, time-critical tasks. The Qantas crew had time and managed it, and other resources very well.
In critical instances such as a high speed RTO we should review the tasks which we ask of the crew. We could better match the task to actual capability (as indicated by accident reports) and not necessarily persevere with assumed human performance based primarily on engine failures during takeoff (possibly in older / slower aircraft), particularly where nowadays engine failures are less frequent.

[john_tullamarine]

Like I said earlier, never argue with an idiot, they drag you down to their level, then beat you with experience.


Sometimes I think I am far too tolerant. Tidied up a few posts .. hopefully we can get back to rational and pertinent discussion ...

[SinglePilotCaptain]

Actually John...your tolerant to the same 4 trolls in here, and ban the people they jump on for fun.....if you want to fix these problems might I suggest you reign in the obvious trouble makers..

If your just about making friends and not promoting any serious discussion on aviation...put that on the banner, I won't come back....

I think your guise as a wise and tolerant moderator is a pretty thin veneer.

Sincerely,

Johns, SSG, ect....

[Brian Abraham]

your tolerant to the same 4 trollsThe people you complain of as being trolls are actually practising or retired professional aviators from a very wide background, helo, corporate, airline, GA, military etc.

You would be more than welcome to share these pages (speaking for myself) if you didn't carry on with the Walter Mitty story telling. You bluff no one who has any aviation credentials, and may in fact be something of a safety hazard by influencing an audience who don't have the background to be able to sort the wheat from the chaff.

not promoting any serious discussion on aviationThere is plenty of serious discussion to be had, but with your lack of knowledge and unwillingness to accept the advice of experts you are in fact the one who derails the serious aspect.

I think your guise as a wise and tolerant moderator is a pretty thin veneerJohn Tullamarine is indeed a wise and tolerant moderator, and has a background in aviation that gives him truly encyclopedic knowledge, though I'm sure he would blush and deny at me saying so.

might I suggest you reign in the obvious trouble makersI think that has just been done.

Should you have a change in heart as to how you engage you will find the community here welcoming with open arms and with a very warm embrace.

Peace be with you.

Sincerely,
Brian

[aterpster]

Brian Abraham:

Should you have a change in heart as to how you engage you will find the community here welcoming with open arms and with a very warm embrace.

Your message is well stated for the most part, and in particular about John. But, I believe good engagement in this forum doesn't necessarily result in very warm open arms.

[safetypee]

Is there any data for RTOs which resulted in serious incidents or accidents, particularly those commenced above V1, indicating other contributory / external factors, i.e. less than the recommended overrun distance / area.
The line of thought is that if an ‘overrun’ is contained in a safety area without major damage, then these may not appear in accident statistics and thus hide a potentially higher rate of high speed RTOs – incorrect decision but successful outcome.
Conversely how many incidents became accidents because of systematic failures; the crew decision (> V1) might only have been the initiating contribution.

[mutt]

For someone operating a single pilot jet that requires a 5,000 ft ASD from a 10,000 ft runway, there is some logic in deciding to abort on the runway prior to VLOF rather than take flight following an engine failure or some other serious malfunction, especially considering the work load for a single pilot.... however, where do you draw the line, are you willing to do the same on a 9,000 ft runway or even a 7,000 ft runway? In order for you to make a rational decision, you should know what version of FAR 25-109 your aircraft was certified under, the brake condition, and even the calculations methodology used for the AFM.

When you move into the airline world or even the larger corporate world, things change, the aircraft that you fly are designed to operate in the most economical manner possible, you may fly different variants of the same family, (A320/321)(A330/340), there is no possible way that you can know the different characteristics associated with each tail number or runway. But you should be aware if your airline has adopted a Min or Max V1 or optimized V-speeds policy and the reduced thrust policy?

When the people sitting in some dark office decided how these aircraft were going to be operated, they had days or even months to review all of the related facts, to look at in-depth details about the aircraft's performance, the airport, the runway condition and in some cases they have even walked the runway to ensure that the data is correct. For more obscure runways they may have flight tested the departure profiles in a real Flight Simulator, or flown test flights into the airport. The result of all that work is given to the crew on one sheet of paper, it gives a limiting take-off weight at a specific temperature/pressure/wind and it gives V-speeds.

With the aim of reducing high speed rejected takeoff's and enhancing safety. The industry evolved into being more "Go Minded", V1 changed from being a "Decision Speed" into a "Action Speed", a training aid called the Boeing Takeoff Safety guide was released circa 1991 to educate people about RTO's and the correct methods to be used during an RTO. Its worth reading...

Some may ask you to second guess the decision to reject once above V1, but surely if this was the safest option, then in the last 20 years since the formation of the Boeing Takeoff Safety group, then the teaching methods would have changed!

As a final note, As these are anonymous forums the origins of the contributions may be opposite to what may be apparent. In fact the press may use it, or the unscrupulous, or sciolists*, to elicit certain reactions.

Mutt

[SinglePilotCaptain]

Let me translate that for you Mutt....for clarity sake...

'When you fly corporate the boss is sitting in the back with his family, he doesn't want his pilot driving the plane to the fence and pulling it off...but when you fly for the airlines, and the flying public has no clue as to how a plane should be flown...it's ok to burn up all the runway with reduced power take offs, because when you bring the plane back to the shop, your own mechanics, who are compelled to stretch the engine overhaul times out as far as possible, can have an easier time not seeing things in the boroscope during the inspection process.

It's all about having enough insurance for each passenger seat, vs paying for more engines, and if you hire cheap pilots, who believe that burning up runway on purpose make sense, in some alternate reality, they can walk up and down the aisle telling the passengers, that safety is first, and actually believe it.."