The first purpose-built propulsion system for the ScanEagle unmanned aerial vehicle has been delivered to Insitu Inc. by an Australian company.

Orbital Corporation Limited said the reciprocating internal combustion engine for small UAVs will now undergo Boeing in-house testing and development.

"Delivery of this first engine is a major milestone in the UAV propulsion engineering project," said Terry Stinson, Orbital's chief executive officer and managing director. "Insitu is very satisfied with the program results to date, and the team is already moving forward to achieve our next target."

The Orbital propulsion system incorporates the company's new Argon Engine Control Unit and control system, which features real-time monitoring and diagnostics of critical systems, sensor and actuator redundancy, and "black box" recording.

It also uses the company's FLEXDI technology, which provides enhanced performance for heavy fuel SUAS engines and extends aircraft range. Insitu and Orbital have also combined technical capabilities to reduce engine vibration and noise.

Orbital has been working with Insitu, a subsidiary of Boeing, since 2013 as part of an initial design, development and validation contract to supply UAV propulsion systems.