Aerrow
Akkerman
Allied Signal
Allison Engine Co.
Alturair
Alvis
AMFUEL
BMW
Boeing
Davis Diesel Development, Inc.
D-Star Engineering
Flite-Lite Inc.
Herbrandson
Heward Microjets Ltd
Hybrijet Engines
Lightning Aircraft Engines
Lycoming
M-Dot
Microturbo Inc.
Moller International
Motto Guzzi
Nelson Engine of Florida
Norton
Private Research Co.
Quadra
Rolls Royce Inc.
Rotary Power International Inc. (RPI)
Rotax
Sachs
Sonex Research, Inc.
Sundstrand Power Systems
Technical Directions Inc.
Teledyne CAE
Thielert Aircraft Engines GmbH
UAV Engines Ltd. (UEL)
USQ Aero, Inc.
Williams International, Inc.
Yanmar
Zanzottera