> shouldn't depart controlled flight in an effort to maintain altitude Aircraft isn't inherently stable in a level flight, otherwise there would be no need for

> shouldn't depart controlled flight in an effort to maintain altitude Aircraft isn't inherently stable in a level flight, otherwise there would be no need for autopilot. There are constant small corrections. And when the engines dies the plane starts to drop the nose but not with an exactly 0 degree roll, because nor the weight is distributed ideally nor the atmosphere is an ideal gas. And while I don't know how far the plane should be out of the flight parameters for the AP to disengage, you should remember what it is still tries to correct the plane (while not yet disengaged) but the dwindling engine power (and hence airspeed) make the control surfaces less effective, so now the AP needs to over-correct and this how you end with rudder and elevators stuck in weird positions and sending the plane anywhere but the stable gliding path. Though in this case it's less probable becaue looks like the engines were still working, if I understood some sources right.