Would you abort after V1?
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Would you abort after V1?
Assume you have 5000 ft extra runway past your balanced field length, your light, cool weather, everything is in your favor...you accelerate past V1 twards V2, and you get an engine fire...
Would you fly it off the ground or try to stop it?
Would you fly it off the ground or try to stop it?
Sorry, no brainer.
What have you briefed?
What have you been trained to do?
What would you be doing for a living now if you'd rejected after V1 in your last Sim session?
We are go-minded for a reason. A high speed reject, even under the circumstances you outline, is a high-risk manoeuve. Taking it into the air has proven to be the safest option time and again.
Now let's talk about the legal ramifications if you took it upon yopurself to reject above V1 and you ran it into the weeds- Hope the family home is held in trust!!
What have you briefed?
What have you been trained to do?
What would you be doing for a living now if you'd rejected after V1 in your last Sim session?
We are go-minded for a reason. A high speed reject, even under the circumstances you outline, is a high-risk manoeuve. Taking it into the air has proven to be the safest option time and again.
Now let's talk about the legal ramifications if you took it upon yopurself to reject above V1 and you ran it into the weeds- Hope the family home is held in trust!!
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I'd continue the take off, no question. After all, the whole point of having a decision speed is to simplify things in the heat of the moment. Presumably you've formed a contract with the rest of the crew in the pre-t/o brief regarding your actions in case of emergencies - if you break it you'll create chaos and confusion. If you survive then you ought to expect a percussive debate shortly thereafter!
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Ok I also know the answer to that, and what Iīm supose to do in the Simm, but what would have happened to the Air France Concorde if they had aborted ....? maybe someone had survived surely the ones in the hotel underneath......, I fly an ATR and most of the times we take off within the first 30% of runway ,so still left 70% and many times I wonder the same question ..... is it really safer 100% of times , whichever a/c you fly and conditions you encounter ?
Good question, thanks for posting .
Good question, thanks for posting .
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Assume you have 5000 ft extra runway past your balanced field length, your light, cool weather, everything is in your favor...you accelerate past V1 twards V2, and you get an engine fire...
Stopping distance is only part of the equation. Simply because one has runway ahead does not imply a successful rejection of the takeoff. Controllability, brake energy, directional issues all play a factor. An airplane at 130 knots is not the same airplane it was at 80 knots or 40 knots when it comes to getting stopped.
An engine fire is a controllable problem; one that need not merit the hazards of a high speed rejected takeoff as well. One might as well get in the air, as one is past the decision point, handle the problem effectively, and return to land stable and in control with ample runway ahead.
V1 is planned such that flying off with an engine failure or other problem is safe and controlled, whereas stopping is no longer part of the equation.
The engine is on fire continuously in normal operation. That the fire is outside the engine rather than in doesn't provide any justiifcation for abandoning plans mid-stream and entering into an unsafe condition in a state of panic. It's an engine fire. Worse case scenario, fuel chop it after getting away from the ground, and come back to land.
I don't know how many fires you've experienced outside a simulator, but my own experience has been that once the fire is detected, sit on your hands and count to ten, then address the problem with a workable cadence and some measured patience.
You're not going to try to throw in some ten tonne overgross takeoffs or disasters involving closed, dark, short runways again, are you?
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Just to clarify i am no airline pilot but as soon as i read the tittle "Would you abort after V1?" i thought it was some sort of joke thread.
As i say i am no airline pilot but i know enough about the consequences and risks of aborted takeoff after V1 and i would say always GO!
As i say i am no airline pilot but i know enough about the consequences and risks of aborted takeoff after V1 and i would say always GO!
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It's no joke; he's serious. The original poster has started a new thread to press his arguements from this thread: http://www.pprune.org/forums/showthread.php?t=326707
He's baiting respondants by putting the extra five thousand feet out there, trying to show that most pilots don't think, and are afraid to reject the takeoff.
He may as well have put a big safety net across the runway, or a giant pillow at the end, or even extended the hand of the almighty as a means of slowing the aircraft...all sorts of ridiculous teasers could be put there to say "but surely you'd reject if this were the case."
Fact is, V1 is established as the speed at which time for rejecting the takeoff is over, and going flying is as briefed. Time to fly.
He's baiting respondants by putting the extra five thousand feet out there, trying to show that most pilots don't think, and are afraid to reject the takeoff.
He may as well have put a big safety net across the runway, or a giant pillow at the end, or even extended the hand of the almighty as a means of slowing the aircraft...all sorts of ridiculous teasers could be put there to say "but surely you'd reject if this were the case."
Fact is, V1 is established as the speed at which time for rejecting the takeoff is over, and going flying is as briefed. Time to fly.
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The most important issue of aborting after V-1 would be brake energy limitations in my opinion. However, that being said I have operated aircraft off of 10, to 15,000 foot runways with a BFL of less than 5,000 feet. As the actual ground run distance was in the neighborhood of 3,500 +/- feet that would leave at least twice to three times of distance of runway remaining verus runway used to stop.
I feel that comes down to Situational Awareness. If I was in a lightly loaded 727 with a BFL of 5,000 feet and was taking off on a 12,000 foot runway I would discuss aborting after V-1 with the rest of the crew. However, you have to take into consideration the type of aircraft you are operating. In the 727 for an example V-1 is also V-R under most conditions. Therefore, in the 72 the point is mute because unless the reason for the abort is a major flight control malfunction or failure there is an excellent chance that after V-1 you be airborne; an entirely different situation requiring you to land the aircraft to abort, not a good idea.
But..........remember the AA DC-10 accident at Chicago. In that case putting the aircraft back down on the runway could have very possibly save many lives. Then again maybe not.
I guess the bottom line is, if in the slightest doubt, fly.
I feel that comes down to Situational Awareness. If I was in a lightly loaded 727 with a BFL of 5,000 feet and was taking off on a 12,000 foot runway I would discuss aborting after V-1 with the rest of the crew. However, you have to take into consideration the type of aircraft you are operating. In the 727 for an example V-1 is also V-R under most conditions. Therefore, in the 72 the point is mute because unless the reason for the abort is a major flight control malfunction or failure there is an excellent chance that after V-1 you be airborne; an entirely different situation requiring you to land the aircraft to abort, not a good idea.
But..........remember the AA DC-10 accident at Chicago. In that case putting the aircraft back down on the runway could have very possibly save many lives. Then again maybe not.
I guess the bottom line is, if in the slightest doubt, fly.
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You go. There are many variables to consider weight, type of a/c etc. In a heavy once you pass v-1 you're stopping data is invalid. Trying to stop 830,000 lbs from 170 knots with limited space is something I would not recommend. An engine fire can be dealt with in flight and an immediate return overweight is possible if you do not want to take the time to dump if the fire warning is still on.
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Between 80kts and V1 I will stop for a fire, engine failure, smoke, structural damage, blocked runway....
If the call is GO, OR speed is ABOVE V1, I will continue the take-off.
That is what you've briefed, and that is what the other guy (we are multi crew after all) is expecting you to do.
So, there is no decision to make, because the decision needs to be made before V1.
If the call is GO, OR speed is ABOVE V1, I will continue the take-off.
That is what you've briefed, and that is what the other guy (we are multi crew after all) is expecting you to do.
So, there is no decision to make, because the decision needs to be made before V1.
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Surely, the time for making all these decisions is before you brief the TO, while working out the speeds. At that point, if you notice that you have excess runway length, then you can (if the data exists to permit it) select a nice high V1 if you so desire, and work out in a nice calm atmosphere that you do, indeed, have the runway, brake energy, etc. to do so. Then you can brief that V1, and fly to it.
But having picked the V1 and briefed it, you've made your choice.
But having picked the V1 and briefed it, you've made your choice.
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Couldn't agree more, if there is no issues with runway length and performance, and the figures agree, then the V1 would be the same as the VR (or on my type 3 knots less becuase the bug is 3 knots thick).
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) at V1.
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) after V1.
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) even when the engine and the pylon departed the aircraft and took the left wing slats with them.
Therefore, the TORA at Chicago was completely irrelevant to any decision process that the crew could possibly have made.
I flew the DC-10 for 8 years and it was not a great "stopping" aeroplane but it was a great "going" aeroplane. A lot of people were killed by decisions to stop after V1.
If you need any convincing, try looking at the Spantax DC-10-30 disaster at Malaga. All they had was a burst tyre on take-off but a decision to shut the throttles AFTER V1 resulted in the inevitable overrun on to a motorway (if my memory serves me right).
Had they continued to get airborne, they had enough fuel to fly to Tierra del Fuego in Chile and book a bunch of taxis and hotels on the way.
Once you shut those throttles, you have no more options available.
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) after V1.
The crew of the AA DC-10 at Chicago did not know that they had a 3 foot crack in the pylon of No.1 engine (caused by very dubious maintenance procedures) even when the engine and the pylon departed the aircraft and took the left wing slats with them.
Therefore, the TORA at Chicago was completely irrelevant to any decision process that the crew could possibly have made.
I flew the DC-10 for 8 years and it was not a great "stopping" aeroplane but it was a great "going" aeroplane. A lot of people were killed by decisions to stop after V1.
If you need any convincing, try looking at the Spantax DC-10-30 disaster at Malaga. All they had was a burst tyre on take-off but a decision to shut the throttles AFTER V1 resulted in the inevitable overrun on to a motorway (if my memory serves me right).
Had they continued to get airborne, they had enough fuel to fly to Tierra del Fuego in Chile and book a bunch of taxis and hotels on the way.
Once you shut those throttles, you have no more options available.
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Interesting...
Come on Guppy...don't give it away....
So the consensus is?
Flying a burning aircraft up through the soup, fighting the fire while in the circut for single engine approach is more acceptable then simply pulling back the levers and adding some brakes.?
So the consensus is?
Flying a burning aircraft up through the soup, fighting the fire while in the circut for single engine approach is more acceptable then simply pulling back the levers and adding some brakes.?
Last edited by ssg; 17th May 2008 at 18:58.
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If there is an excess of 5.000 feet of runway, that means that you are:
i) Taking off very very light
ii) WAT or SSLW limited
iii) Limited by very close obstacles.
For i) case you could equal V1 to VR. Let say your ATOM is 52T and your OTOM is 80T( RLW). If your actual V1 is 112 KIAS, VR 116 KIAS, Why donīt increase V1 to 116 KIAS if V1 for OTOM is 130 KIAS?
For case ii) you can increase V1 according your AFM-OMB and use an ICP procedure if approved by the manufacture.
For case iii) no solution.
In all the cases above, V1 must be calculated prior to take off, the speed must be fixed. Above V1 you must go. But remember that you can set different speed for diferent scenarios.
When I take off very light I always increase V1 tro VR, for me is much safer to RTO with an excess of 5.000 feet than became airbone with an engine failure or any other major malfuction and fly for 15 stressing minutes.
If the take off is runway limited I will stick to the normal V1 and be Go-minded
i) Taking off very very light
ii) WAT or SSLW limited
iii) Limited by very close obstacles.
For i) case you could equal V1 to VR. Let say your ATOM is 52T and your OTOM is 80T( RLW). If your actual V1 is 112 KIAS, VR 116 KIAS, Why donīt increase V1 to 116 KIAS if V1 for OTOM is 130 KIAS?
For case ii) you can increase V1 according your AFM-OMB and use an ICP procedure if approved by the manufacture.
For case iii) no solution.
In all the cases above, V1 must be calculated prior to take off, the speed must be fixed. Above V1 you must go. But remember that you can set different speed for diferent scenarios.
When I take off very light I always increase V1 tro VR, for me is much safer to RTO with an excess of 5.000 feet than became airbone with an engine failure or any other major malfuction and fly for 15 stressing minutes.
If the take off is runway limited I will stick to the normal V1 and be Go-minded