"A small space to rise from is sometimes as great a danger for a plane as a forced landing, too," interrupted the Colonel. "Say you're forced down on a mountain ledge, or a tiny island--the average plane is done for then. Has to be deserted to its fate for the lack of a long, smooth runway needed for the forward glide before the rise. Were you figuring on the straight-up rise, as well as the straight-down drop, with this heli--, I mean gyroscope business?"