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Disclaimer: Not a pilot or an aviation guy, just someone who's flown on planes before.

So, yeah. Assume A and B are the PIC and copilot, respectively, of a twin-jet plane (doesn't matter which one). B calls out "V1" and half a second later before V2/rotation speed both engines "magically" cut out. So, now what would A do? Or what would you do? Conventional wisdom says you should only reject the takeoff over V1 is the aircraft is incapable of flight, and I would point out that having both engines fail before you can even take off, with less than enough space to decelerate safely, is the epitome of an aircraft being incapable of flight.

Would this be a situation where there isn't really more to do but cross your fingers, and slam on the brakes, figuratively speaking, and hope that you stop before you overrun the runway or stop short enough that everyone survives? The thing is gonna stop at some point thanks to physics. Might as well ensure it stops as safely as it can, then assuming everyone's alive or not too badly unhurt, have a chat with the NTSB/local regulation authority about it.

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    $\begingroup$ With no engines running, you ARE NOT going to go fly, and the only choice is how hard you work to slow down, so that you go off the end of the runway slowly, because you worked hard, or fast, because you didn't initiate any braking. I'd recommend closing this question since it's really a duplicate of your other one, and I've addressed that scenario in the answer there. $\endgroup$
    – Ralph J
    Oct 1, 2023 at 22:49
  • $\begingroup$ @RalphJ I looked at the other question and agree it's a duplicate. VTC this one. $\endgroup$
    – user22445
    Oct 2, 2023 at 0:18
  • $\begingroup$ @RTO That was my other question, yes. $\endgroup$ Oct 2, 2023 at 1:19
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    $\begingroup$ You really answered your own question here in the body of remarks... What else is there to say? $\endgroup$ Oct 2, 2023 at 16:40

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Basically, yes. You will get on the brakes and hope for the best. If the runway is 10000 ft and your accelerate stop distance at max thrust is 7000, no problem.

If the runway is marginal, or you are using a "flex thrust" power setting (where you use just enough power to meet the departure requirements of that runway, to go easy on the engines - flex is widely used), you are cutting it close, but there is some fudge factor built into the distances, where for example, it's assumed there is a couple of seconds delay in getting on the brakes. You might roll of the end, but you won't be going very fast, and if what's off the end is inhospitable, like approach lights or a cliff, you might decide to drive off the side of the runway instead when getting close.

Actually, the "go no matter what" concept post V1 isn't completely cast in stone. A captain may elect to reject after V1 but before rotation, where something happens that casts doubt in the ability of the airplane to fly, such as a loud bang coming from the back just after V1, and there is excess runway margin available. A rare circumstance, but possible.

As a statistical matter, the double simultaneous engine failure is not even accounted for in risk analysis, because the probability is well beyond the risk threshold at which you must mitigate the risk of a complete loss of the airframe by design; namely, a probability worse than 10⁻⁹, or one in a billion.

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  • $\begingroup$ Yeah -- the more realistic case of rejecting after V1 is because your plane simply refuses to fly (such as if a tab-flown elevator is jammed and won't let you rotate, to bring up a couple recent examples) $\endgroup$ Oct 2, 2023 at 2:38

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