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PA-31P Navajo crash Laredo Intl KLRD

Tragic outcome.


LGMG Megara, Greece

These twin “loss of control” crash videos tend to look fairly similar. A rapid and total destruction.

Administrator
Shoreham EGKA, United Kingdom

Turn to final too tight?

Novice pilot
EDVM Hildesheim

Plausible. the aircraft definitely was in a roll towards the left (dead) engine. Clearly the pilot lost control, either on final or when turning final.

For a single, the “typical” accident at this point would be stall / (incipient) spin. @Peter, It wouldn’t look that different if it happened to a single…

An asymmetric twin at low power turning towards the dead engine will be more prone to entering a spin, since it naturally yaws towards the dead engine and has less airflow over that side, too. Increasing power on the good engine is the equivalent of adding (a lot) pro-spin rudder and (a bit) pro-spin aileron, unless you simultaneously compensate with rudder. Easy to get wrong, and for that reason turns towards the dead engine require caution, and power changes in that turn and at low speed doubly so.

It could also be a minimum control speed rollover, but these are more of an issue at high power settings, and not so much at typical approach power settings unless you want to go around or need to correct your approach path a lot.

The outcome of both is the same. The aircraft enters an uncontrollable roll over its back and drops the nose quickly, at these heights it will perhaps manage a quarter to half turn before impacting ground with the nose down.

One way or the other, a twin is harder to handle in these situations than a single. You get the chance to fly a circuit which you don’t get in a single, though…

Biggin Hill

Cobalt wrote:

One way or the other, a twin is harder to handle in these situations than a single.

That would not have happened with a Push Pull.

Berlin, Germany

I have no experience with twins but wouldn’t the best course of action – assuming the failed engine was secured and not on fire – to fly a very shallow turn with a wide radius and low bank angle? Wouldn’t this make controlling the asymmetric thrust much easier?

Novice pilot
EDVM Hildesheim

MedEwok – yes, there is never any point doing anything involving large bank angles on one engine. Nice and gentle, take your time, dont rush. We have debated this many times before. The reality is most twins fly and handle very nicely on one engine, but when an engine fails for real there is inevitably an element of panic and a temptation to rush the process. I think this is often the cause of some of these type of accounts.

Would it be safer not to turn toward the dead engine? A right traffic might have led to a better outcome.

EDFZ

Raise the dead.

Actually the key is ensure the aircraft is trimmed, you arent counteracting roll with rudder that hasnt been trimmed. Once trimmed there is little in it although obviously the aircraft will already have a little bank so there is less bank available.

A well trimmed aircraft, flown at the right speeds and with the ball centered (or 5 degrees into the dead), I would argue it doesn’t matter which way you turn or which engine is out. It only matters when those criteria are not met – and then it can get hairy very fast.

This accident probably is more related to stall turn matters and the fact that Vmca increases significantly in anything but level flight 5 degrees to counter the yaw. Vmca is only certified for straight and level flight. The minute it’s not that anymore, Vmca speed goes up.



Last Edited by AdamFrisch at 14 Mar 22:29
15 Posts
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