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Twins - engine failure / EFATO (merged)

AdamFrisch wrote:

For sure. Seems to be a spate of King Air crashes at the moment. Not sure why. On paper, this should be a pretty straightforward recovery, but perhaps training is lacking or there’s a misunderstanding about Vmca. Vmc goes up anytime you’re not in straight and level flight, not banked into good engine, not at MTOW etc. Maybe they just didn’t have enough margin?

Not sure it’s that simple. On the King Air 250 I fly Vmca is only 92kts, and you would generally take off at a higher speed than that. Vyse is 116; for that reason we are looking for 120 as soon as reasonably practical.

Darley Moor, Gamston (UK)

King Airs, except for the 100 which has Garretts, use a free turbine PT6, so the auto feather mechanism should be straightforward, and the engine torque effect on failure is also less serious than on a shaft turbine. There have been partial failures on the FCU (fuel control unit) which might result in confusion, but this pilot appears to have been very experienced so would be alert to this.

Will have to wait for the report, but I would not jump to the conclusion that the pilot was rusty on his EFATO drills. As what_next points out he appears to have flown the aircraft under control to the scene of the crash so no Vmc event. The press say he used the radio to advise a catastrophic engine failure, which covers failures where the propellers failed to feather for some mechanical reason.

Oxford (EGTK), United Kingdom

RobertL18C wrote:

. As what_next points out he appears to have flown the aircraft under control to the scene of the crash so no Vmc event.

Yes but that could also be consistent with pulling back the throttle on the good engine. With correct technique can it climb on a single engine with the other windmilling?

EGTK Oxford

JasonC wrote:

Yes but that could also be consistent with pulling back the throttle on the good engine.

But since the aircraft has auto-feather there would be no reason to retard the throttle? Can a KA pilot confirm the checklist/procedure for this?

ortac wrote:


But since the aircraft has auto-feather there would be no reason to retard the throttle? Can a KA pilot confirm the checklist/procedure for this?

The autofeather may have failed, that was the speculation earlier. If so and in order to retain control the good engine was throttled back, perhaps it was not possible to climb and the unfavourable airport environs meant the forced landing was not survivable.

EGTK Oxford

Sorry I read your previous post to mean that the pilot might have throttled back the good engine by accident, not on purpose.

So, the engine failed, AND the auto-feather failed, AND (the pilot either couldn’t maintain control and had to retard the good engine OR retarded the wrong engine).

The Vmca figure is with the engine feathered if the aircraft has auto-feather (as opposed to a piston where Vmca is with the engine windmilling), which begs the question, what is the effective Vmca on a King Air with the engine unfeathered, and is it anything remotely sensible?

ortac wrote:

Sorry I read your previous post to mean that the pilot might have throttled back the good engine by accident, not on purpose.

Everything is possible. On proon there is even speculation that the friction locks were not tight enough so that the power levers came back by themselves without the pilot noticing. Seems to have happened to others in the past. From my short time on the Metroliner I recall that one had to tighten those locks to the point that the levers were just moveable by hand, otherwise the strong vibrations from these powerplants at takeoff setting would move the levers within seconds.

ortac wrote:

So, the engine failed, AND the auto-feather failed, AND (the pilot either couldn’t maintain control and had to retard the good engine OR retarded the wrong engine).

There are failure modes which include all those "AND"s: A prop governor failure for example which in the worst case can drive the propeller into reverse.

EDDS - Stuttgart

what_next wrote:

On proon there is even speculation that the friction locks were not tight enough so that the power levers came back by themselves without the pilot noticing. Seems to have happened to others in the past.

That’s what is said to have happened at Blackbushe.

EGKB Biggin Hill

I don’t get this at all. Why wouldn’t you simply move the levers forward again?

ortac wrote:

I don’t get this at all. Why wouldn’t you simply move the levers forward again?

I don’t know from what background that pilot came, but when flying part 25 / transport category aircraft one is supposed to let go of the power levers once V1 has been called out and not touch them again until reaching at least acceleration altitude (which he never reached) – whatever happens. This is forced into us by means of drill, so to say.

Last Edited by what_next at 24 Feb 13:26
EDDS - Stuttgart
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