engine falilure after V1 before VR and a long runway?

[CA1900]

Once in a blue moon something occurs that demands an abort anyway...but very, very rarely...

Those extremely rare moments might occur in which one can and should still get stopped; jammed controls may certainly be among them...

Exactly. "Well, we have lots of runway left" should not be one of the factors in whether to abort after V1. "It won't fly" is about the only reason I can think of for a post-V1 abort. And those are extremely rare. As others have pointed out, high-speed aborts tend to end badly, whatever the reason.


We had just such an abort a while back -- one of our planes got to rotation speed, and the elevator wouldn't move. They aborted at a little over 100 knots on a 7000-foot runway. Fortunately it was dry and the airplane was light, so they were able to stop it in time.

As it turns out, the trim wheel was removed for a maintenance procedure, and was reinstalled 90 degrees from where it was supposed to be. Unfortunately, the trim index is on the knob, not the pedestal, so the crew had no way to know. (Raytheon's poor maintenance manual doesn't directly address this, as I understand it. Ours does -- now.)

The elevator was trimmed severely nose-down, hence the elevator feeling jammed on takeoff. We've added a procedure to the crew-change preflight to run the trims to their stops and back to center, to be sure they stop at the red lines, and that should catch it if it ever happens again.

 

[100LL... Again!]

If there is a serious concern as to whether the aircraft could actually fly, I would consider such an abort.

An extreme example might be a collision with wildlife. Anyone see the posters with the bizjet that is severely damaged by an elk, I think?

That said, COULD you abort a slower turboprop on a very long runway even after getting airborne? Sure, propbably, but why would you want to?

These are transport category aircraft, and it is important not to fly them with a GA light-twin philosophy.

 

[100LL... Again!]

We had just such an abort a while back -- one of our planes got to rotation speed, and the elevator wouldn't move. They aborted at a little over 100 knots on a 7000-foot runway. Fortunately it was dry and the airplane was light, so they were able to stop it in time.

I that situation, I think the crew made the right call. I've met some pilots that mechanically think that V1 is inviolable under any and all circumstances. Too much book-learnin' and not enough common sense.

 

[Groucho]

V1 is not a hard number anymore

With the advent of computerized weight and balance and performance data, V1 is now computed on a specific airplane, weight, temperature, and runway condition at our airline. There is no specific hard number. It can be increased for incrased cliimb performance, if runway lenght and aircraft weight are not limiting. It can be reduced with an incrased flap setting for contaminated runways to improve stopping capability.

For high hot and heavy operations, such as Las Vegas in August, V1, V2 will be upagainst the limiting tire speed, runway length considered, to improve second segment climb performance.

The fact of the matter is, is that with computerized performance data V1, V2 and other factors can be computed on a case by case basis to optimize performance.

To answer the orginal question, yes V1 can be increased to improve climb performance or some other paramater. You do not however change the way we handle V1. Once computed, by whatever method, prior to V1 for an engine failure, we stop. After V1 we continue the takeoff.

I hope we are all confused now at a much higher leve.