BAC 221

The BAC 221 was a British experimental aircraft created by extensively rebuilding an existing Fairey Delta 2 research aircraft with a new, more slender ogival delta wing matching the planned wing shape of the Concorde supersonic airliner. Flown through the 1960s, it gathered high-speed aerodynamic and handling data at supersonic speeds on the ogival delta planform before Concorde itself flew, reducing the risk carried into that much larger and more expensive program. The aircraft work complemented the low-speed research flown in parallel by the Handley Page HP.115, together forming the two ends of the flight envelope the Concorde design needed to prove out.