Why did they add a fake propeller to the Bell XP-59A? The Bell XP-59A was the first American jet aircraft. To protect the secret jet project from enemy spies, U.S. Army Air Forces' personnel disguised it with a fake propeller added to the XP-59A when it was on the ground during early flight tests. The dummy propeller was meant to fool prying eyes into thinking it was just another new piston engine aircraft. But a jet aircraft it was, and it flew for the first time on this week in 1942. The XP-59A is in our collection and is on display in Boeing Milestones of Flight Hall at the Museum in DC. #AirSpacePhoto