Intended to win the Kremer prize, the Musfly was designed by David Cook and Neil Moran, who at the time were employees at Richard Garrett & Sons, at Leiston, in Suffolk.

[2] Pitch control would be by weight shift, with the crewed capsule, suspended beneath the wing, being moved back and forth.

[2] In the capsule, the two-person crew would operate treadles in order to power a pusher propeller, which was to be positioned slightly below and behind the wing.

[2] The aircraft was built by Cook, with assistance from co-designer Moran, Chris Tansley, Terry Aspinall, Bob Jelliff, Brian Pattenden, and others, with the primary airframe being completed by September 1977.

[2][3][4] Work on the aircraft continued till at least 1979, and was nearing completion when Cook lost use of the building that it was being housed in.