- Bede BD-5 canard derivative (seen in Rutan's hangar circa 1974, uncompleted).
- USAF VariEze (built and flown circa 1979).
- Ganzer Gemini (a derivative of the VariEze).
- Model 59 Predator project (how different was it from the Model 58?).
- Model 61-R Rodie, also found as the Rodie LEZ, a secret modified Long-EZ belonging to McDonnell Douglas (first flown in August 2001).
- Model 79 Commuter airliner type project (how different was it from the Model 78?).
- Model 89 pre-Starship 1 SCAT design
- Model 111, an early design with joined wing for what became the ARES.
- Monkey Green Army-built Long-EZ for covert ops (flown circa 1984).
- Model 126 HALID (whatever that was).
- Mercury (the ill-fated British derivative of the Model 97 Microlight).
- Senior Citizen, a classified transport, probably for the ASALT program.
- Man-powered helicopter concept (designed circa 1988).
- Man-carrying ornithopter concept (designed circa 1988).
- Model 169 tactical tilt-rotor concept (designed circa 1988).
- Model 170 canard tactical tilt-rotor concept for Bell (designed circa 1988).
- Model 173 TFV towed vehicle for Loral (first flown July 1989).
- Purpose-built test aircraft with scimitar-shaped propeller for supersonic
- B-2 Bomber RCS Model, 40% scale pole model for Northrop (tested circa 1989).
- Model 179 Rockbox (PLADS) eight-man parachute delivery vehicle for Lockheed (first flown November 1989)
- Lima 1 conversion of Piper Aztec with Lexus engine on right wing (first flown circa 1990).
- SU-25 ROAR rocket-powered cable-mounted 1/4 scale decoy for Sandia National Laboratories (first flown April 1991).
- Grasshopper/Maliboo, a forerunner of the White Knight/SpaceShip combo.
- Orion, apparently an unmanned vertical take-off vehicle (related to Aurora Flight Sciences Orion HALL UAV?) .
- Task Vantage Williams-powered jet version of Long-EZ (first flown August 1993).
- Kistler K-0 launch vehicle (prototype built at Scaled in
1995 and probably scrapped before completion).
- Aeolus 1 manned high-altitude balloon system (flight tested in 1996).
- Model 254 Songbird piston twin aircraft (for private Korean customer, apparently not
- Model 260 Tier II+ UAV proposals for USAF competition.
- Nosejob performed on a Convair Samaritan test aircraft.
- MB-300 Boomerang prototype for Morrow Aircraft (first prototype partly completed then stored, fate unknown, 2002).
- Model 301 Pronto light jet aircraft design for Pronto Aircraft (preliminary design for the Eclipse 500).
- Seeker pusher engine, h-tail UAV program, no details.
- Phoenix full-scale version for the film "Flight Of The Phoenix" (was built but never flown as it was too heavy).
- Defender high-altitude laser-capable interceptor UAV for Livermore Labs (reportedly built and flown circa 2005).
- Whispercraft full-scale movie prop, seen at Scaled in September
2005 (did they have anything to do with it?)
- Sensorcraft (AFRL/Northrop Grumman), Scaled involvement unknown.
- Model 356 Dynamite, an 8-place development of the Boomerang for Dale Johnson.
- Model 372, a boat/aircraft convertible, Burt's last known design to date.