Handley Page Type D

The Handley Page Type D, later redesignated H.P.4, was a single-seat, single-engined tractor monoplane and the first Handley Page design to fly more than a few hops. Only one was built. It was the third and last of the company's early single-seat monoplanes, after the Type A, which crashed on its first turn, and the Type C, which never flew, and like them it used the wing patent of the Weiss design that promised automatic lateral stability but failed to deliver it. Built for the 1911 Olympia Aero Show, it needed a new fuselage to take a 50 hp Isaacson engine after a borrowed 35 hp Green engine proved too weak. It crashed at the end of its first flight on 15 July 1911, and after repair it was named The Antiseptic by test pilot Edward Petre and nicknamed the Yellow Peril, flying several times from Fairlop before Handley Page turned to two-seaters.