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Thread: Rejected take-off past V3BS

  1. #1
    Senior Member Gabriel's Avatar
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    Default Rejected take-off past V3BS

    This take-off was rejected not after V1, not after V2, but after V3BS (the fictional speed at which, if you reject the take-off, you can still stop the plane maybe not on the runway but in a safe zone beyond it). The plane overran the end of the runway, broke through the instrument landing system and approach lighting, the airport perimeter fence, went over a road and came to a stop on a ditch about 340 meters/1120 feet past the runway with all landing gear broken and collapsed.

    The pilot rotated (or tried to) at 152 kts (that's at or past V1 already) and kept accelerating for several seconds reaching a maximum sped of 173 knots because the plane failed to pitch up. The left elevator was found jammed (although post accident the controls were verified free and correct post accident, understanding that in the MD-80 we are talking of all the linkage from the yoke to the control tabs, which in turn provide the aerodynamic force that moves the elevators).

    No injuries.
    Maybe, if the pilot had insisted with the take-off, the plane would have eventually and safely lifted off and flown (the right elevator was working ok and the elevator has quite more nose-up authority than nose-down authority, plus they may have added more nose-up stabilizer/trim)
    I am sure that, had the airplane caught fire, and caused a few dozens deaths, we would be blaming the pilot for aborting the take-off after V1.
    I am sure that, had the pilot continued trying to take-off and failed, crashing at a much higher speed and killing a few dozens, we would be blaming the pilot for not aborting the take-off shortly after Vr when the plane resulted unable to fly.

    Both decisions (insist with the take off or abort at a very high speed) could have gone well or terribly bad, and the pilots had no means to judge what would be the outcome of either decision.

    As a side note, both pilots were captains:
    The PIC is the airline's chief pilot and was in the right seat, he was acing as PM and providing type differences training to the pilot in the right seat. 10K TT, 2.5K on type.
    The PM in the left seat had 15K TT, 8.5K in the DC-9 family (of which the MD-80 is part, under the same type certificate)
    So experience was not lacking there. What was the impact of that in the outcome, I don't know.

    http://avherald.com/h?article=4a5ecf6a&opt=0

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  2. #2
    Senior Member Evan's Avatar
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    If you pull back on the yoke at 152kts and get no rotation, it's not gonna fly. Why give it more time? Reject immediately!

    This has been my argument about the inviolable GO doctrine of V1. There is a clause in there that says 'unless the aircraft is not safe to fly'.

    If the pilot had rejected above V1 at the moment is became apparent that the aircraft wouldn't fly and a dozen people died, he could not be blamed for that.

    If there's any confusion about that amongst pilots, that needs to be addressed, pronto.

  3. #3
    Senior Member 3WE's Avatar
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    Quote Originally Posted by Gabriel
    ...V-3BS...
    V-3BS is that you can still abort, but that the subsequent crash will likely be survivable! These guys did it with genius and aborted before V-3BS

    Quote Originally Posted by Evan View Post
    If you pull back on the yoke at 152kts and get no rotation, it's not gonna fly. Why give it more time? Reject immediately!

    This has been my argument about the inviolable GO doctrine of V1. There is a clause in there that says 'unless the aircraft is not safe to fly'.

    If the pilot had rejected above V1 at the moment is became apparent that the aircraft wouldn't fly and a dozen people died, he could not be blamed for that.

    If there's any confusion about that amongst pilots, that needs to be addressed, pronto.
    Psychology is a tough thing. Do the pilots ever ask themselves "are we gonna make it?". Do they not become conditioned to trust that the plane is going to accelerate as it should, lift off as it should (albeit with an 'slightly narrow margin')

    https://www.youtube.com/watch?v=jn7fLUS5WRE

    Does their recurrent simulator training (and not the majority of actual aborts) involve an engine failure. Isn't failure to rotate a damn damn rare thing?

    What about this one?- I don't see the proverbial, by-the-book, 3-degree per second rotation...are we again, having to sit back, ignore what could be, and trust that it will take flight like it always does.

    https://www.youtube.com/watch?v=nm-q9BEWMGU

    Again, I ask you to call on your tricycle or bicycle riding experience...ever notice tunnel vision...moments of not knowing what to do as it falls away underneath you?
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

  4. #4
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    If you pull back on the yoke at 152kts and get no rotation, it's not gonna fly.
    That is factually totally wrong. Most of the times it will and most of the times it did, and possibly it would have this time.
    Wrong weight, wrong Vr, wrong CG, wrong trim, wrong flaps...

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

  5. #5
    Senior Member Evan's Avatar
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    Quote Originally Posted by 3WE View Post
    Psychology is a tough thing. Do the pilots ever ask themselves "are we gonna make it?". Do they not become conditioned to trust that the plane is going to accelerate as it should, lift off as it should (albeit with an 'slightly narrow margin')

    https://www.youtube.com/watch?v=jn7fLUS5WRE

    Does their recurrent simulator training (and not the majority of actual aborts) involve an engine failure. Isn't failure to rotate a damn damn rare thing?

    What about this one?- I don't see the proverbial, by-the-book, 3-degree per second rotation...are we again, having to sit back, ignore what could be, and trust that it will take flight like it always does.

    https://www.youtube.com/watch?v=nm-q9BEWMGU

    Again, I ask you to call on your tricycle or bicycle riding experience...ever notice tunnel vision...moments of not knowing what to do as it falls away underneath you?
    Engine failure is damned rare as well.

    As you know, I'm aware of tunnel vision and human factors, but training is supposed to defend against these things. We have engine failure before/after V1 as a memory item because this is a critical—every second counts—moment of decisive action. It must be a practiced response governed by some very black and white procedure. The same can be done for failure to rotate, tire failure, fire warning, etc. I say it can be done, not that is necessarilly is being done.

    Here we have a crew, a chief pilot in the right chair and a very senior one in the left, both captains, rotating through 152kt on an MD-80 (?!!) (presumably nowhere near MTOW) and then... one one-thousand... two one-thousand... three one thousand... four one thousand... five one thousand (now over 170kts)... reject!

    There's something wrong there... I know that's a very quick five seconds but this is where pilot material comes in. Pilots need to be conditioned to recognize when a plane isn't likely to fly, and to reject immediately (within one second). If everything is working right, the aircraft should be able to rotate below Vr. If you get negative pitch response above Vr, think: control surface failure and reject!

  6. #6
    Senior Member Evan's Avatar
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    Wrong CG, wrong trim, wrong flaps... all good reasons to stay on the ground and try again.

    Wrong weight, wrong Vr? 152kts in an MD-80? I don't think you can get a Vr that high even at MTOW, not in Michigan anyway...

  7. #7
    Senior Member 3WE's Avatar
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    Quote Originally Posted by Gabriel View Post
    That is factually totally wrong. Most of the times it will and most of the times it did, and possibly it would have this time.
    Wrong weight, wrong Vr, wrong CG, wrong trim, wrong flaps...
    THANKS! I had forgotten that there was a LONG list of incidents where 'continuing' was THE right answer...which is why the black and white recommendation is to almost always continue past V1.

    Indeed, if it's clear that the plane will not fly, invoke V-3BS (or ideally V-1) and hope for the best...it's just that things are much clearer when judgmentally posting on the discussion forum than watching the red lights approach at 150+ knots...
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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