Bede XBD-2

The Bede XBD-2 was an experimental short takeoff and landing (STOL) aircraft, with several novel features such as structural use of glass-fibre and aluminium honeycomb, a suction boundary layer control (BLC) system and fuselage-mounted twin engines driving a pusher configuration, shrouded single propeller.

The boundary layer was controlled with a suction system via 160,0000 upper wing and aileron surface holes, with diameters ranging from 0.020 to 0.029 in (0.51 - 0.74 mm).

The XBD-2 was powered by a pair of flat-six piston engines mounted inside the fuselage, driving a single pusher configuration propeller, turning within a circular shroud.

They drove the rear propeller shaft through ten V-belts via Sprag clutches to avoid engine speed synchronisation problems.

[3] It was intended to lead to the BD-3, which would have been a six-seater with bigger engines, more use of honeycomb panels, retracting undercarriage and a laminar flow wing,[1] but this was not built.