Agree

but... the issue in most overrun accidents is the timing of the effective actions to stop relative to intersecting the critical speed.

To continue requires much less motor skills.

Thanks galaxy, I was thinking that myself. Putting in MTOW into the laptop to see a max V1 speed for the runway conditions - just really so that you have a mental idea of what you have remaining in terms of your balanced field speed reduction from a V1 stop situation. For instance at a light weight, v1 = 116, and the same at MTOW would be for example V1 = 149, but would you really want to delay VR to 149 in a ferry flight!

I am not advocating anything here, more that I want to know what margins we have been given when presented with a V1. I wonder if operators do not make this kind of data available in an easy format so that the stop/go decision is clear cut - rather than make it a 'greyer' area at lower weights as people could have 2 values to consider.

Interesting quote from that 'Pilot Guide to Takeoff Safety':
"By far, the most likely takeoff scenario for the
line pilot is the case where the actual airplane
weight is less than any limit weight, especially
the Field Length Limit Weight. It also is possibly
the most easily misunderstood area of takeoff
performance since the fact that the airplane is
not at a limit weight is about all the flight crew
can determine from the data usually available on
the flight deck. Currently, few operators provide
any information that will let the crew determine
how much excess runway is available; what it
means in terms of the V1 speed they are using;
or how to best maximize the potential safety
margins represented by the excess runway."

And another one w.r.t. tyre failure:
"McDonnell Douglas Corporation,
in an All Operator Letter4, has addressed this
dilemma by recommending a policy of not
rejecting a takeoff for a suspected tire failure
at speeds above V1−20 knots."

Is this out of date or used in any other type/fleet?

Totally agree!!

From all the heated discussions, points, examples, etc offered on this thread... I think one thing has become obvious. It doesn't matter what you fly, when it comes time to think outside the box, I think most pilots do just that! In a Caravan, a bang above V1 means stop. In a Navajo, it depends where your decision point was, your weight, speed, incline, etc. In a Citation, I'm guessing the same would apply. In a 747, one bang is not serious, however 2 bangs would make you think "same engine, or 2 on the same side?".

All of these decisions depend on so many factors, it is unfair to try and compare airline pilots with anyone else.... it all depends on the factors relative at the time.

I think all SSG was trying to point out (initially) was this fact, but then got involved in a mud-slinging session with a whole bunch of people from other fields.

Bottom line is.... we all do what we think is correct at the time, according to the situation at the time. Our training does teach us different things, but we aren't just machines... we're humans, who assess things quite fast (normally), and, because we are humans, we are sometimes prone to making mistakes.

For me, V1 means "go". But that isn't true for every take-off... and my fellow crew-members know that, because I tell them... everytime, when it's relevant. Every take-off is different... no-one can dispute that.

SOME DAYS YOU'RE THE BUG... SOME DAYS YOU'RE THE WINDSHIELD

A great deal of informed and erudite comment on this thread has been of considerable interest to a mere PPL like me (if I lose an engine my command decisions are pretty limited).
However one thing shines out very clearly from the discussion. V1 is being used for two different things - 'good-to-go minus one engine' and 'committed to take-off'. For low take-off weights and long runways these are often nowhere near the same value. Why has it evolved this way? Why can there not be an extra parameter in the take-off litany?
'V1' - 'Commit' - 'Rotate'
Then someone asks 'would you ever stop after 'commit' and the arguments go on ;-)

V1 is not a rule, it's a guideline for judgements.

It makes little difference in how hard you set it. The outcome is subjective (statistical)

As an example the incident/accident rates for takeoff aborts are typically calaculated for anything over 100kts, since the data gathering is unsure exactly when the pilot decided to start the abort.

Dont Hang,

The reason is that, particularly in large aircraft, a go decision has proven to be the safer option for almost all emergency situations even if, theoretically, you COULD stop on the available runway. High speed rejects are very serious manoeuvers. If the aircraft will fly it is virtually always safer to takeoff, circle, and land thus having the WHOLE runway to stop on, rather than just the bit left after V1.

lomapaseo-

It most certainly IS a rule according to the Ops Manual I am LEGALLY REQUIRED to operate in accordance with. As Captain, I do have the right to work outside the laid down procedures if it is necessary, but that means something has happened so that I CAN'T continue the takeoff.

Wizofoz

A trifle quick on the retort aren't we

You can express your own statements quite nicely and they will stand on their own. But please don't mess with mine, I'll be happy to back mine up anytime I feel it's necessary.

If it makes you feel any better I agree with what you said, but I do not retract my statements.

lomapaseo,

I apologize. I've only been dipping into this thread, and thought, wrongly, that you were another manifestation of SSG. Shows how one fool can muck it up for everyone!

Having read your posts in there entirety, I see you have a very firm grasp of the realities of the whole concept of V1 and Go/No go.

Wizofoz---Ssg has gotten everyone a bit stired up---;)


PA

[I'm still in therapy from the reduced thrust thread:}]

Ay Ay Ay e jole
 

(That's espanish). Now that the cattle are off the runway, I'll drop the gear and squat. Observation. There is a sense here, and it isn't just because it's the "net", that way too many posters have skin thin enough to read the Guardian through. The quickest and loudest are usually the people who have the least to offer. I've done that, that's how I know to recognize it when I see it. So easy to angrily condemn a post, and then push one that wasn't worth the wait.

Maybe people are just too shy to begin new threads; I think that would help. More subjects, better venue, more thread integrity.

V1? Coffin Corner? Pilot's who pack? It's all good.

Airfoil

No worries.

I'm inclined to accept my limitations in communicating and prefer instead to let all posters express themselves and then take for myself the best of the communication.

I learn a lot from this, including to temper my own opinions.

Simple Math
 

Why try to stop on 20 or 30 or 40 percent of a runway when you can take it in the air and come back and use nearly 100 percent of the runway to stop? There is a very good reason as to the WHY we train to GO after V1.

Ok. I'm no pilot but isn't it abit stupid for a pilot to try and stop the plane with only 50 percent of the runway left?
I mean the speed of the plane will require more runway to stop and wouldn't the plane just simply go off the runway and crash?

Only if you assume that acceleration and deceleration rates are identical. They aren't. Most vehicles (of any sort) can brake at a higher rate than they can accelerate.

Reject after v1
 

All aircraft manufacturers assume that the person reading the procedure is an average pilot, not a hotshot. That is to say they try to cover the whole community and not just a gifted few.
Almost all of the cases where a reject has been carried out after v1 have resulted in an overrun.
How would you decide in a matter of a couple of secs whether it would be safe to reject t.off after v1 on one rwy and not the other.
All a/cs are certified to fly on one eng and there are fire extinguishers to put out the fire.
And if it is possible to reject t.off and stop the a/c with the remaining length of the rwy then the calculation of the v1 is obviously incorrect, maybe the aerodynamics of the a/c do not permit to control the a/c at that speed for a reject.
So please, it is prudent as a community to have a procedure which in this case is to continue after v1. Maybe one will successfully reject the t.off and stop after v1, but it will be your last t.off i promise you , the training department will sack him without blinking.

Welcome back SSG.

SSG or whatever name you go by......

How many 800,000 pound limiting runway take-offs have you done where 8000 feet of runway remaining is available. I'll bet you would have no doubt as to what to do at, or past, V1 in heavy weight widebody aircraft with a problem. Stopping is not an good idea, trust me. Yes, a Citation on a typical 8000 foot runway has a oodles of space and stopping is a possible, if uncalculated, outcome. But put it on 3500 feet, cliff at the end and a summer day and I doubt you would advocate stopping past V1 either.

GIVE IT UP!

What's that whining noise in the background? Ah, ssg is back :rolleyes:

derfecty may/may not be ssg ... so long as he/she posts appropriately, he/she can stay ... we are not in the business of conducting Salem trials ..

However, if folk are of the view that his/her posts represent only nuisance value, there remains the option of ignoring them .....

If, on the other hand, his/her posts stray into areas of unacceptable behaviour .. the outcome will be a programmed decision ...

Hmm!. Isn't there something about 'walking like a duck and talking like a duck'......?

http://www.pprune.org/forums/safety-...ml#post4226822

Nice to know you are watching, Mr Mod:ok:

While I may have (and am perfectly entitled to) my view on the matter .. the mod role ought not to be coloured by presumption and prejudice .. really we are here to facilitate, not rule.

Hence I give a lot of rope .. just that some folks use it up quicker than t'others...

Your department? You're a microsoft sim pilot, you're ssg, the banned poster...your tune hasn't changed on iota, and like your other multiple personalities, you'll manage to get yourself banned before long too.

SSg has single handedly managed to turn what's long been an excellent technical forum into a worthless laughing stock because of posts just such as this, as well as each of the threads he's ruined just to get his little teenage jollies.

Certainly another persona to put on the ignore list, until it too gets banned in a day or so.

sometimes i really do wonder, how come it's stuck to his head... and up to now... he's still at it. :E

Post V1, any number of things can happen to a plane to make it un-flyable...to persist in the concept that all planes fly after V1, no matter what is quite silly....None the less, I have been admonished for stopping a plane on the runway (sim) in a post V1 cut, plenty of runway, but got the 'debate' from the sim instructor. I simply reply that in the real world, saving lives is what it's about. On that note, I find it funny, that the guys that fly the plane off in the sim, only to hit that mountain, because as they were fighting the fire, they forgot to make the turn...simply got to do it over again...I like how another poster put it...' with a burning lake of lava at the end, using up 90% of my runway for balanced field, sure, it's a go after V1...but with another 5000 ft left, a 1000 ft stopway at the end, and a thousand miles of Nebraska corn fields beyond, why would I fly a burning wreck up through the air and become a test pilot with a planeload of people?'

Mush,
You only become a test pilot when you operate an aircraft outside of its scheduled performance.

i.e. stopping above V1

FE Hoppy...If balanced field is 5000ft and the runway is 10000 ft, I am not being a test pilot...by stopping post V1, Pre VR, braking distances are easy to calculate...Flying a plane that just clipped a fuel truck, got hit by an RPG, had a tire go through the fuel tank, just lost one side of slats and flaps from the car that it ran over, is being a test pilot.....

Show me where you can find the stopping distance required for a speed above scheduled V1?

Hoppy, I put on the brakes the same way 6 billion people do every day when driving thier cars...I look out side, and decide if I have enough pavement to stop or not...how do you know if your plane will accelarate to VR with those busted tires with in the given runway distance?...do you have the new calcs for that?.

If I think i can save my life (and that of my crew and pax) taking off a 2500meter runway in a turboprop; yes, i may abord after V1......

Hoppy “You only become a test pilot when you operate an aircraft outside of its scheduled performance”.
Nope, :) ;) but I agree that you should not stop above V1.

MushinPilot43 “… is being a test pilot.....” Definitely not! :( t.p’s avoid doing stupid things. The point is that the circumstances which you ‘dream-up’ are extremely unlikely to occur, and then not exactly at the critical time of an RTO ‘decision’. The basis of safety in our industry is probability, minimising risk by dealing with known or foreseeable hazards in the safest way. The definition of foreseeable in certification involves probability; about 10e-6 IIRC.

The weakest component in an RTO (and in most other operations) is the human element. The hypothesising of extreme scenarios does little to strengthen well proven procedures and guidance at critical time.
Safety is not absolute, it is not perfect, and we strive to improve our standards. But in seeking to cover all extremes there is a risk that you will introduce opportunity for error (situation assessment, judgement), or with situation/procedural complexity you change established habits formed in training and exacerbate an already hazardous situation.
Remember that ‘we are what we think’ - we do what we think, thus those with hazardous thoughts (risk taking) have no place in the industry.

The stop/go decision should be one of the easier clear-cut decisions in aviation.
The process normally starts with a trigger event (before V1), where the situation has to be assessed against predetermined parameters or conditions (SOPs). You should not have to consider the nature of the condition – tire, surge, or mentally debate the severity or effect; this is done before flight and covered by procedure and training detailing how they might be identified etc, even if relevant.
Where the aircraft is not flyable (normally established after V1), then there isn’t a go decision; you will stop sometime, all you can hope to do is minimise the damage. It will not be an RTO, but it will be an accident, as will in all probability, be an RTO after V1.

This happens to you often in your daily operations as a professional pilot, does it? You see a lot of airplanes running over cars on the runway and attempting to continue the takeoff? You've seen this, ever? Do you know what an RPG looks like? Do you have any records of aircraft continuing takeoff after being hit by one, or any being hit by one during takeoff, for that matter, or are you tossing idiotic scenarios wildly in the air for any purpose other than to cloud an issue in which you have no place nor debate, ssg?

You're the same guy who posts under all the other names, gets called out, and eventually banned, with the same stupid agenda, as always. Mushinpilot43 is ssg is tankdriver is...same banned poster under a different login. Again. Nothing to see here but stupidity in action, folks.

At balanced field length you legally must abort before V1 or go past V1 to be safe. If you don't do that you are not legal. However if logic says I have extra runway today and I have leeway then think about what is more important, being legal, or being safe. I have briefed many departures with cliffs at the end of the runway differently than departing with an obstacle. My most critical airport was Tegucigalpa, Honduras. It had a 4 ft fence and a 70 ft drop off at the end. How would you like to overshoot an abort on that short runway? Taca just did a demo on that one on landing.

Well according to Mushin we'd better study our hit by an rpg or run into a fuel truck checklists. At least you are consistent in your ignorance.

Oh, lookee. No Mushin to respond (banned, of course), but here is Fisssle, suddenly having appeared...with one post. One name disappears, next appears, brand new poster, with the same story. Imagine that.

Such a surprise.

Do it now! :mad:

http://i294.photobucket.com/albums/m...nsubscribe.jpg

I'm starting a new thread-as this one may have run its course:}

"would you abort after V2?---I'm sure I'll get plenty of rational responses:ouch:---well time to practice my Vmc/stall/spins in the face of of TS---with a sick pax so I have a reason under 91.3 para c.---to go below minimums on an IAP:}

ooouuuu.... now I know why you chose that screen name ....

So SSG #5 (or 6 by now), the recent overrun in BRU is apparently an abort after V1, (Only a preliminary report, not the final) and the outcome while not fatal, may have been much worse with pax on board.

Simple
 

Just always consider your partner with that answer, and fly like a real crewmember with good judgement and good CRM......