Originally Posted by Woof etc
...Assuming failure of the critical engine and the prop auto-feather system:
- Would the yaw be containable with reasonable force at V2 with the operating engine at TO power?
- Would the aircraft be able to maintain altitude in take-off config?
Hello Woof:
I have never flown a Jetstream, and I have no knowledge of that aircraft at all. I have, however, over 5,000 hours experience giving instruction in full-motion twin turboprop simulators, and based on that experience, I'll try to answer your question in a generic manner (meaning, not speaking to this specific accident).
You asked if "yaw would be containable with reasonable force". I don't think force is really the issue. The most important issue when dealing with an engine failure in the takeoff phase of flight is to maintain airspeed - ideally, to keep airspeed close to V2 or Vyse (which one it is depends on the certification basis of the aircraft), and at the very least, to keep airspeed above Vmc.
As airspeed degrades, the amount of force required to fully deflect the rudder and ailerons decreases. So do the chances of being able to successfully recover from the engine failure at takeoff. A twin that has only one operating engine has a very narrow speed range within which it will climb, and if too much kinetic energy is lost and there is no potential energy (altitude) available, the chances of increasing the airspeed back to that V2 or Vyse target - an essential prerequsite to climb or even level flight - become very remote.
In other words, it's not the yaw from the windmilling engine that is the problem, it is the degradation in airspeed that arises from the windmilling engine that is the problem.
As to your question about maintaining altitude in takeoff configuration, I am not aware of any twin turboprops that can maintain altitude with only one engine operating in the takeoff configuration (gear down) and the failed engine windmilling.
Again, I want to emphasize that I am not speaking to the circumstances of this particular accident, I'm speaking in general terms about twin turboprops.