IFR student looking for help understanding engine failure, critical engine and critical speed! Thank you!

From your original post, I feel like I should also note that asymmetrical thrust is caused by the fact that the engines are mounted out there on the wings and not on the centerline of the airplane.

Yes you get drag from the failed engine, causing yaw in that direction (a good deal of this is eliminated when you feather the dead prop), and that drag exacerbates asymmetrical thrust, but the asymmetrical thrust is caused by the operating engine- it's mounted way out there on the wing and because of its distance from the centerline of the airplane, its thrust causes yaw toward the dead-engine side. Imagine that the engines were mounted on the wingtips and one of them failed and you'll get the picture of how asymmetrical thrust works.

The rest of your question was answered very well by /u/Striderrs. You understand that prop singles have left-turning tendencies, correct? And what causes theses tendencies, correct?

Same thing here. It's just two singles fused together. Both of 'em want to turn left for the same reason that a single wants to turn left. If the left one stops making thrust, the one out there on the right keeps on trucking, but it's effect on the whole thing is greater than if you'd lost the right one because it's left-turning tendency is being aided by that long lever arm.

If you loose the right one, the left still wants to turn left like always, but the effect is automatically countered somewhat by the reduced thrust on the right, the drag from the right, and the fact that the left is now using its lever arm and asymmetrical thrust to the right. It's still going to yaw and roll toward the failed engine, but not as much as if you'd lost the left one.

As noted previously- twins with counter rotating props don't have a critical engine.

/r/flying Thread Parent