Another odd interview question
 

Here's one for rumination: You're rolling down the runway, and past V1 you encounter windshear, such that you do not reach Vr. What do you do?

The prevailing train of thought is that if you don't take off, you're going to crash. Consequently, you firewall the thrust and rotate at whatever speed you manage before the end of the runway.

The other is that if you can't make Vr, you're going to crash, so should execute a high-speed abort. You may overrun the runway, but it's better to do so at 30 knots (or whatever), than at 130 knots.

Thoughts?

To me it would depend on where I was....short runway or long.

X

I wouldn't be so worried about not getting stopped by the end of the runway - with windshear overrunning the runway is a good outcome to me (although obviously not ideal). After you get in the air will you be able to climb is the real question? I'd be more afraid of a no to that answer than overrunning the runway.

Freeze up and panic!

Seriously, I think these type of interview questions are more about seeing if you can make a sound, defensible judgment call under stressful conditions than any "right or wrong" answer. Your answer will reveal much about your flight experience, training, and ability to make a decision and stick to it.

Obsess about answers to specific type interview questions like this, and you'll freak out when they ask you a question you didn't anticipate and prepare a canned answer for.

For the Trekkies: It's a Kobayashi Maru Test . .. "There is no right or wrong answer, it is a test of character."

Generally speaking, in the big airplane world a high speed abort is much more dangerous than taking an airplane into the air with a problem. There are certain circumstances where the airplane won't fly so the abort is called for. The question is is this one of those instances. More information is called for.

Military TOLD always includes a refusal speed. On dry runways that is generally higher than rotate which is usually go speed. Above rotate/go speed and below refusal you can still abort by the end of the runway. You might burn up the brakes and blow the fuse plugs but you will stop. I am still trying to wrap my head around civilian TOLD. V1 seems to be close to CEFS. I am still just concentrating on calling out the right things at the right time! :D

So to answer your question, it would depend on the scenario. Is it a small/big airplane? What runway and where? Obst? What kind of windshear, ie micro burst? What is the weather? Hopefully the interview question fleshed some of those questions out when posed to you.

All that being said, if you were close to V1 I wold stop and pray I wasn't at Guam.

At the gate I briefed... any problems after V1 I will take the aircraft into the air and we will climb to a safe altitude, troubleshoot and run any appropriate checklists, declare an emergency if necessary, and return to XYZ airport.

That would be my answer. V1 and Vr are usually so close together that if you come across V1 you usually are already at or within a few knots of Vr so do as you briefed and as you are trained. If your airspeed hits V1 and then degrades below V1 then you are below V1 and again do as you briefed and are trained.

We are talking about a split second decision here, so make your call and then stick to it....the only right answer is the one that leads to everyone getting off the airplane alive.

Its definately something to keep in your mind on a day where the DA is high....its hot and your heavy.

Depending on the length of the runway...balanced field length and all that stuff determines what you should do. In my opinion??? If the field is long enough...abort...I brief that after v1 one of the few things ill abort for is loss of directional control, which depending on the severity of the windshear could happen.

Though few and far between, their are instances where you will have to abort past v1 or sometimes even after vr. We used set and elevator jam at rotation in the sim for the lear 60. Crews had no choice but to abort. Just to show them that its possible that you may not have a choice.

The Boeing procedure is to continue the takeoff. Rotate at the 2000' remaining point regardless of airspeed. This has been the procedure we have taught at both UPS and Delta on the 737/757/767/747-400/777 fleets. With today's wx radar and predictive wind-shear systems it would be rare to be surprised by wind-shear. The crew probably would have made allowances for wind-shear advisories(i.e increased rotation speed based on RATOW, max thrust, different runway etc.). The key to the question is that you are above V1.

My companie's ops. manual addresses this case and states to initiate a normal rotation at least by the last 2000 feet before the end of the runway.

The DAL procedures specify that you would fire wall (ie cook) the engines and rotate with 2,000' feet of runway left even if you haven't reached VR. If you think about it this is the logical choice. Statics show that you are almost guaranteed to crash attempting to abort above V1, but may very well be able to fly under the circumstances. The ability to safely fly in that situation is, as someone said, an unknown, but it's less of an unknown that the likely outcome of the alternative. (aborting after V1, history shows an almost guaranteed crash)

This logic is further bolstered by the common guidance given to justify aborting after v1. "only if the aircraft is unable to fly" Well in this scenario you're not really sure about the flyability'. If the weather is so bad that you do have assurance that you can't fly then you shouldn't have been attempting a TO in the first place.

The Lear with the elevator jam at v1 is a no brainer and really a different discussion, as you would be certain the Lear would not fly. It is, however, a good example of a situation (however unlikely) that you would definitely abort after v1.