- 3W International GmbH
- Austro Engine GmbH
- GE Aviation (The General Electric Company)
- Hirth Engines GmbH (UMS SKELDAR AG)
- Honeywell International Inc.
- Orbital Corporation Limited
- Pratt & Whitney (United Technologies Corporation)
- Rolls-Royce plc
- BRP-Rotax GmbH & Co KG
- UAV Engine Limited
- Ballard Power Systems Inc.
- MicroMultiCopter Aero Technology Co. Ltd
- HES Energy Systems (H3 Dynamics Holdings Pte. Ltd.)
- Intelligent Energy Ltd.