engine falilure after V1 before VR and a long runway?

[atr42flyer]

what would you do?

I would think that you would continue with how you pre-briefed the departure with the other crewmember. I also remember somthing about a max V1 which is usually higher than both v1 and vr. i know there are lots of people smarter than me so what would you do? lets just say your in a regional jet of some sort.

 

[KeroseneSnorter]

what would you do?

I would think that you would continue with how you pre-briefed the departure with the other crewmember. I also remember somthing about a max V1 which is usually higher than both v1 and vr. i know there are lots of people smarter than me so what would you do? lets just say your in a regional jet of some sort.

V1 is defined as takeoff decision speed......so I am not sure what your question is. Anything after V1 and you are going, period.

Maybe the only other issue would be massive structural damage from a catastrophic engine failure that makes the airplane unflyable or something, Maybe a deer strike or something else like that will put the ability to fly into question, in that case maybe sliding off the end is better than trying to go in when flight ability is in doubt.

There are few runways long enough to get a transport catagory jet stopped before running off the end if you are past V1 speed.

EDIT: I see what you are asking now....but unless you specifically calculated the absolute maximum V1 for the takeoff, you have no idea if you have enough runway or brake energy left to get stopped, so you go with what you know, after v1, you go. Simple engine failure it is never a queston, post v1 you go.

 

[fogrunner]

V1 is defined as takeoff decision speed

Not anymore.. The definition was changed in 1994 by the FAA


V1 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.

At Gemini we call V1 5 knots early. Our training is basically once we hear V1 we are committed to the t/o. Even at our max weight, with reduced power settings we can safely meet all climb requirements.
Why compound your problems with an abort after V1 IE very hot brakes, brake fire, blown tires, now you have controllabilty problems.

 

[81Horse]

At Gemini we call V1 5 knots early. ... Why compound your problems with an abort after V1 IE very hot brakes, brake fire, blown tires, now you have controllabilty problems.

Oh, man -- I'm with you. I don't like waiting until it's very V1.

 

[CA1900]

...unless you specifically calculated the absolute maximum V1 for the takeoff, you have no idea if you have enough runway or brake energy left to get stopped, so you go with what you know, after v1, you go.

Yup. Here's an extreme example of what happens

Mesa 5326 Report (Cached version, as the NTSB database is down right now. If that link fails, here's the live link whenever it's back online.)


In short, the airplane got airborne, and the frozen-up stall horn started going off. 20 feet in the air and climbing, the captain said, "Abort! Abort!" It wasn't a simple engine failure as we were discussing, but the criteria are the same: You're above V1 and the airplane's flying, you continue. You have no idea if you have enough runway left to stop. (And in the case of this accident, they didn't.)

 

[User546]

Interesting report.

Can someone explain this phrase:

"The sound of the horn ceased, at 0922:28, and the captain called out, "abort Doris Doris," at 0922:29. The CVR recorded the sounds of impact and the recording ended, at 0922:31."

 

[avbug]

If you're above V1, you're going, period. That you have more runway in front of you means you have an obstacle free clearway...that's good...but it's not there for stopping.

High speed aborts are dangerous. Period. Ever wonder why the FAA limits abort demos on practical tests to 40% of your refusal speed? The FAA knows, based on history and statistics, that a high speed abort stands a fairly high probability of ending badly, and there's no reason for it.

If I have a long runway, I may leave well enough alone and use the calcualted V speeds. If it's a shorter runway, I may include a primary refusal speed; any malfunction prior to that speed, I'll abort. Above that, I'm only aborting for critical items, such as engine fire, engine failure, or loss of directional control. My decision, made before ever entering the runway environment, may also be tempered by surrounding terrain, runway gradient, runway surface condition (eg, contaminated runway), and so forth. NBAA and other safety organizations have suggested 80 knots as an all encompassing refusal speed (or decision speed, if you will), where one will abort for any light or indicated malfunction.

You should have briefed the contingencies. If you're past V1 and encounter a problem, you're way, way beyond the time to be reconsidering or second guessing your preflight planning and briefing.

By the time you hear V1, you're right on top of or passing through Vr and well on your way to V2 in many cases. In most aircraft, that transition period doesn't last long, and trying to split knots or one second from the next is thinking too much...it can get you hurt.

A more interesting possibility that I've seen in practice on actual take offs and in simulator sessions, is a split between crewmembers. In the sim, for example, I see a malfunction. The PF is so keyed into the takeoff that when I call "Abort! Abort! Abort!," the pilot continues the takeoff. I've seen this happen under actual conditions. The more interesting question then becomes what to do when faced with a reason to abort, and the other pilot disregards the instruction.

A worldwide generic industry rule, given in various forms, is that one challenges once, and then challenges again. If no response at the second challenge, one assumes incapacitation and takes control. However, that's awfully darn generic, and may be downright unsafe. I've had to do it twice in my career, and on both occasions there was no time to second guess and there was no other choice. But what about on a takeoff roll?

I was once departing LAX in a Learjet with a newly minted captain. He was very, very weak, and I'd been sent with him on the theory that a "strong" (don't laugh; it wasn't my decision) pilot would make up for his deficiencies. This individual was scared to death of flying into LAX; just mention of the place made him nervous. He missed the call to position and hold on 25L, and seemed nearly overloaded. I could tell he was very focused on his takeoff. Just prior to airspeed coming alive I got a master warning and a main cabin entrance door light (forgive me if I get the annunciation wrong; it's been a little while).

I called out the malfunction, and called for an abort. It was within our prebriefed abort criteria, and within the speed envelope. He failed to abort. I called it again, but noted the airspeed rapidly increasing through indicated and then 80 knots. I glanced over my shoulder, noted both the upper and lower door handles forward (door had to be locked, it was probably a handle not fully down or a microswitch issue). Satisfied that continuing was far safer than trying to wrestle the airplane away from him and execute a high speed abort, we continued. I called V1, rotate, and called positive rate.

No response. Again I called positive rate. No response. I said "I have your gear," and raised his gear. The remainder of the initial after takeoff was the same way. After the after takeoff checks were complete, I poitned at the master warning and then the door light, and repeated, "You ARE aware we have a door ligth and a master warning light?"

For the first time he saw it, and I could see him nearly panic. He completely lost his focus, demanding to know "what shall we do? What should I do? We're going to abort! Declare an emergency, let's do a 180 and land!" Absolutely useless.

I told him we were airborne, continue the climb, and once we were passed over to the high altitude controller I'd go back and have a look. I did, and upon pressing the lower handle down, the light went out.

Sometimes an abort, even though technically warranted, isn't the wisest choice, nor is insisting on it.

 

[FreightGod]

Yeah, but the guy asking the question seems to be flying ATR42s.

Them things may be a different animal than a high-performance jet.

Never flown an ATR or heavy turboprop, but guessing on a V1 speed of 88 knots, Vr 92..?

On a 12000 feet runway?

Perhaps a safe abort after V1 could be made.

If we painted the same scenario with a B-747-200 @ 833,000 lbs and hot temps and reduced power, ya may not want to even think about aborting close to V1...You may fly, but you may not stop.

 

[avbug]

Perhaps a safe abort after V1 could be made.

W(h)eather or not it can be made, it should NOT be made...that's really the point.

 

[Propnose]

Our call outs are 80kts, v1, & vr. We call them out 5kts ahead as well, simply because by the time you get them out of your mouth, you're there. We fly out of IAD all the time which has very long runways, and we never consider aborting after v1. Our pre-departure briefing is probably like everyone else's - we will abort for any malfunction below 80kts, 80kts to v1 we will abort for engine fire, failure or loss of directional control. After v1 we will go flying and take care of the problem in the air.