Aborting T/O after v1...question?
02-13-2008, 01:23 PM
#31
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From The Turbine Pilot's Flight Manual:
"V1: Takeoff Decision Speed
Let's start with V1, takeoff decision speed. Simply put, it is the "go or no-go" speed. If an abnormality occurs before V1 is reached, takeoff is to be immediately aborted. If an engine failure or other abnormality occurs after V1 is attained, takeoff is continued and any problem is treated in flight. Most airline and corporate flight departments have historically used V1 speeds based upon "balanced field length" for their particular aircraft. If an engine failure occurs exactly at V1, the distance required to abort the takeoff and stop is the same as the distance required to continue the takeoff. In familiar multiengine terms, this means that accelerate-go distance equals accelerate-stop distance."
In your example, you got the engine fire indication right at V1. Therefore, it would not only be legal, but also prudent to abort the takeoff.
Furthermore, in my first Captain PC, the examiner started a discussion by asking whether or not there were any circumstances in which I would consider aborting a takeoff after V1. After quite a bit of discussion, it was decided that under specific conditions, you might in fact use your best judgment and decide to abort the takeoff. It's the reason that airplanes aren't flown solely by computers, and that is what Captain's Emergency Authority is for.
In a Saab 340, with at least 10,000ft of runway left, with a possible engine fire, and no other extenuating circumstances - I'd venture to say that I absolutely would abort the takeoff. If it were a B747, with only 7,000ft of runway left - that would be a different story.
"V1: Takeoff Decision Speed
Let's start with V1, takeoff decision speed. Simply put, it is the "go or no-go" speed. If an abnormality occurs before V1 is reached, takeoff is to be immediately aborted. If an engine failure or other abnormality occurs after V1 is attained, takeoff is continued and any problem is treated in flight. Most airline and corporate flight departments have historically used V1 speeds based upon "balanced field length" for their particular aircraft. If an engine failure occurs exactly at V1, the distance required to abort the takeoff and stop is the same as the distance required to continue the takeoff. In familiar multiengine terms, this means that accelerate-go distance equals accelerate-stop distance."
In your example, you got the engine fire indication right at V1. Therefore, it would not only be legal, but also prudent to abort the takeoff.
Furthermore, in my first Captain PC, the examiner started a discussion by asking whether or not there were any circumstances in which I would consider aborting a takeoff after V1. After quite a bit of discussion, it was decided that under specific conditions, you might in fact use your best judgment and decide to abort the takeoff. It's the reason that airplanes aren't flown solely by computers, and that is what Captain's Emergency Authority is for.
In a Saab 340, with at least 10,000ft of runway left, with a possible engine fire, and no other extenuating circumstances - I'd venture to say that I absolutely would abort the takeoff. If it were a B747, with only 7,000ft of runway left - that would be a different story.
02-13-2008, 01:25 PM
#32
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the problem with that is you know the plane will fly, its one of the things that is practices ad-nausum in the sim, you might have some explaining to do after that one
02-13-2008, 01:39 PM
#34
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I can't find the reference again, but the FAA says that the "Vee-One" call should be made so that when the words "Vee-One" are completed, you should be exactly at V1.
02-13-2008, 02:26 PM
#36
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Just in response to the engine fire thing...Engine fire = Engine burning Jet A and producing thrust. If you can't put it out, so what? Worse case the engine burns to the fuse bolts and it falls off...oh well, good thing I only need one anyways. Nothing about a Fire light ever means you can't make it to pattern altitude and fly a normal downwind to a visual or ILS...Abort after V1 and now you have a fire AND a high-speed abort...bad juju.
02-13-2008, 02:45 PM
#37
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Seems that everyone has their own views and points but I believe that it is a situational event. On my type ride I made an abort 20 kts above V1 due to a control failure. As I said this was on a type ride. This issue also arose with the 737 that had a piece of asphalt lodge in the elevator during t/o. They tried to take off after the F/O informed the captain that the controls were jammed. V1 means go in just about every scenario but there are exceptions.
Last edited by Moose Surgeon; 02-13-2008 at 03:09 PM.
02-13-2008, 03:01 PM
#38
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02-13-2008, 04:00 PM
#39
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02-13-2008, 04:14 PM
#40
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Here's an example of an abort after V1. I realize it's not an RJ or T-prop, but illustrative of the point:
http://www.youtube.com/watch?v=HS8slRy3EMA
http://www.youtube.com/watch?v=HS8slRy3EMA
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