"Not exactly helicopter--more of a gyroscope," Hal caught something of the Colonel's fire. "It's been on my mind a long time that one of the greatest dangers of aviation is the huge space 'most any ship needs to come to earth on. I've looked death mighty straight in the eye some several times when forced landings smacked me down in a tree top or on a gully edge--when if I could have come down zup! straight like the drop of a plummet, I could have landed with a safety margin in some small clear spot--"