The SP-540 TRE is based on the established concept like the SP-180 SRE and has a displacement of 540 cc. By doubling the displacement, the power of the engines is increased. The SP-540 TRE is a three-disc Wankel engine with up to 74 hp at 6000 rpm.
As with the SP-180 SRE, the SP-540 TRE is equipped with two independent cooling systems. A water cooling circuit takes care of the cooling of the engine housing, a second oil cooling circuit takes care of the internal cooling of the piston. This is a basic requirement for a propulsion system in aeronautical applications, where continuous performance is a fundamental requirement. Thermal stability is essential, which can be guaranteed by the cooling concept.
The SP-540 TRE can be used with a combination of electric and mechanical drive. In the case of pure power generation, an on-board battery is required, as the Wankel engine generates electricity by means of the generator system. This electrical power can also be used as the primary propulsion. But a hybrid boost mode can also be used, in which the mechanical and electrical propulsion can be combined for maximum performance. Thanks to this integrated hybrid technology, a redundancy function is available that enables a controlled emergency landing in the event of a critical scenario.