Handley Page HP.115

The Handley Page HP.115 was a British single-seat research aircraft built in the early 1960s to study the low-speed handling characteristics of a slender, highly swept delta wing of the kind proposed for a supersonic airliner. Its very low aspect ratio wing, swept back at roughly seventy-five degrees, let engineers gather data on takeoff, landing and low-speed control at angles of attack far outside normal experience, using a vortex-lift effect that later informed the wing design of the Concorde supersonic airliner. Only one HP.115 was built, and it flew extensively through the 1960s in support of the Anglo-French Concorde program before its retirement.