XBD-2 This was a one of a kind research aircraft that incorporated many original and novel features. Some of them are the following: There were two engines - one on the top of each driving a single shrouded pusher propeller. The rear propeller was a highly efficient ducted fan. The entire fuselage was made from all metal honeycomb sandwich material. The all-metal wing incorporated suction boundary layer control for high lift. There were 186,000 holes drilled o the top of the wing skin through which light suction permitted the boundary layer of air to stick to the wing surface, thereby producing significantly more lift. The 14" blower was driven by an extension of the propeller shaft and not only produced suction for the BLC, but also provided efficient engine cooling. This aircraft was the first aircraft in the world to use fiberglass main landing gear strut.