sentences:  Both the basic maneuver and its name are said to have been invented by Len Povey, an American pilot who had served with the Cuban Air Force.Somewhat by accident he performed it in 1936 at the All American Air Race Meeting, which was held in Miami.Povey had intended to perform snap rolls at the top of a loop but was going too fast, so elected to continue over the top of the loop and on a whim, did a half-roll on the way down and did a symmetrical figure in the other direction.