Obviously as a matter of proficiency you should be able to fly a full circuit on the edge of Vmca
Please don’t. Hundreds, not an exaggeration, of students/instructors were lost, some still are, to MEP training by playing around at Vmca. The regulators introduced Vsse (safe single engine) which provides a safety margin, although as the video Adam posted, this is only applicable in certain circumstances, and which made MEP training safer. Circuits asymmetric are typically conducted above blue line (Vyse), and Vref + 5KTAS on established final, to have some energy in the event of an asymmetric go around.
Yes, they never teach you that in training much, but reducing good engine is a surefire way to get out of any Vmca troubles. And it’s a valid technique. Rather crash wings level than spin it in… As you trim up for straight flight in an engine out scenario to return for landing, it always came as a surprise just how much she wanted to go the other way when you rolled off the power. It was easy to forget.
Quote (or 5 degrees into the dead)
“Into” might be confusing but as is recall (And quick mental diagram of forces) it’s into the operating engine (the operating engine is lower, and the ball is on that side)
This thread on twins may be worth a quick read. It seems these procedures are aircraft type dependent to a large degree.
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.
I’ve never flown a twin, but my impression is that you should fly as fast as possible so that you’re well above Vmca and have more control authority. Once you’ve made the runway, wouldn’t it make sense to idle the live motor, so that you have minimal asymmetric thrust and a better descent rate?
Obviously as a matter of proficiency you should be able to fly a full circuit on the edge of Vmca, but in the actual event it seems like giving yourself as much extra margin as possible is better, even if not strictly necessary according to the book.
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.
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.
Would it be safer not to turn toward the dead engine? A right traffic might have led to a better outcome.
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.
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?
