Corvid-50 electronically fuel-injected UAV engine

The Corvid-50 EFI is an electronically fuel-injected two-stroke UAV engine from Currawong Engineering, a 50 cc single-cylinder petrol engine with an onboard generator, built for fixed-wing and other unmanned aircraft in the 30 to 40 kg take-off mass class. Part number CE1224B. It is a combustion engine for small and medium UAV propulsion where range and endurance matter more than the silence of an electric drive.

The engine is built on the Desert Aircraft DA-50 base and modified by Currawong: a custom crankcase and crankshaft, a custom induction system with manifold and throttle body, an integrated isolation mount and a starter-generator. The maker recommends it for aircraft with a maximum take-off weight up to about 40 kg, and gives a typical range of 30 to 40 kg.

For an integrator the key figures are these. Displacement is 50 cc in a single air-cooled cylinder with CDI ignition. Rated output is 2.8 kW (3.8 HP) at 7,000 rpm, which sets the propeller and airframe sizing. Mass is 3.89 kg (8.57 lb) for the complete package: engine, generator, low-noise exhaust, isolation mount and fuel-injection system with the Cortex Hybrid Power System. Fuel consumption is quoted as 503 g/kW-hr (0.83 lb/HP-hr) at 5,500 rpm and 40% throttle, and the alternative datasheet column gives 500 g/kW-hr at cruise, so payload and fuel load can be planned against endurance. Time between overhaul is 350 hours, the interval used for maintenance and cost-per-hour planning.

Electronic fuel injection replaces the carburettor. The package includes a miniature engine control unit, a self-priming fuel pump, a fuel injector with fine atomisation, manifold and cylinder head temperature sensors, and the CDI ignition. The engine runs on premium unleaded petrol, 100LL or MOGAS, although the maker notes that the fuel choice can change the performance figures. Operation and service manuals and an interface control document are supplied.

Electrical integration is handled by the generator, rated 250 W continuous and 500 W in intermittent duty. The Cortex Hybrid Power System is an optional item the maker recommends, and Currawong's power supply can add a remote-start feature. A low-noise exhaust is also optional.

On qualification, the maker states that the engine passed an assessment against the endurance test given in US Federal Aviation Regulation Part 33 (FAR 33).

Typical uses are long-endurance surveillance, mapping, survey and cargo missions with fixed-wing and VTOL UAVs in the 30 to 40 kg class, and as the range-extending power source of a hybrid-electric aircraft.