A self-contained engine test rig constructed by Rotron Power was integrated with Cranfield University’s motor-generator. The initial testing at Cranfield was to ensure the engine and motor would work correctly with each other including coupling and decoupling of the motor-generator with the engine in a running state. The engine incorporates a centrifugal clutch and one-way gear and the motor-generator has an in-built decoupling device). All of this formed the hybrid electric propulsion system (HEPS).
With the engine test rig returned to Rotron Power, a load absorption device in the form of a propeller was attached to the motor to generate some resistance. Initial testing proved successful however more load is required to get the system into a representative aircraft state (the HEPS has too high power for the current absorption device), and thus a dynamometer is to be incorporated into the test rig by Cranfield University followed by further collaborative testing.
Further development includes work on motor-generator system controls, HEPS comms, engine endurance, and exhaust sound reduction.