The Xb-70 Valkyrie First Flew On September 21, 1964. Before Being Retired In 1969 To The Air Force Museum, The Aircraft Was Used Extensively For Supersonic Research And Tests And Contributed Significantly To The Design And Development Of Future Large Supersonic Transports.Mr. Diffenderfer Was Inspired To Create This Painting Because He Felt This Aircraft So Important As A Vital Contribution To Americas Future Leadership In High-Speed, High-Altitude Military And Commercial Flight That A Painting Of It Should Be A Part Of The Air Force Collection.