Can single engine planes glide from a falling position? Near the end of the 50s Sci-Fi movie This Island Earth, the protagonist is escaping from a flying saucer which is crashing to Earth. As he was abducted while flying a plane (specifically a Stinson 108-1), it's sitting in the cargo hold on top of a retracting hatch:



The protagonists then start up the propeller, and once it gets up to speed, the entire hatch seems to disappear and they're dropped vertically out of the bottom of the flying saucer:



They then manage to continue moving straight without going into any kind of dive, before banking out of the shot.

Is this even remotely possible? I would have assumed that when they leave the system of the flying saucer, they will lose the speed which the saucer has and will basically be falling in a stationary position as they have no lift due to the air only hitting the bottom of the wings.
It's remotely possible, assuming you can find a suitable UFO :-) If you drop an object from an aircraft it starts falling with the same airspeed that the aircraft has, until drag or other factors slow it down. If you've ever seen a flour bombing competition (or just watched some WW2 movies or documentaries) you may have noticed that you drop bombs before you reach the target, not when you arrive directly over it.

So if the UFO is moving forward at an airspeed greater than the Stinson's stalling airspeed (65mph) - let's say 80mph - then the Stinson will fall into the air at an airspeed high enough to generate lift immediately and it will fly. If you already have the engine running and throttle up as soon as you fall out of the UFO, you will generate thrust and maintain the flight.

In reality - if there is such a thing when a UFO is involved - the Stinson is almost certain to lose some altitude and the wake turbulence from the much larger UFO will have a significant (and potentially very dangerous) effect if the Stinson can't stay ahead of it.