The A99HF propulsion system is a heavy fuel and gasoline engine designed for small Group 3 unmanned aerial systems. Built on the proven A33 internal core, it features a spark-ignited, liquid-cooled two-stroke inline triple architecture. This configuration reduces primary and secondary shaking forces and provides low acoustic output.
The system is available in multiple configurations, including a pure internal combustion setup and a parallel hybrid option that combines engine and motor power on a single shaft.
The engine incorporates a combustion system capable of operating on VP C9, JP5, JP8, Jet A, and gasoline, providing flexibility for military and industrial operations. Additively manufactured components such as the cylinder, crankcases, mounts, intake, and exhaust enable design features that improve performance, reduce weight, and optimize packaging.
The system includes a direct-drive starter generator, full-size spark plugs for high-altitude operation, integrated preheating, altitude and cold-start compensation, onboard data logging, and CAN and serial communication interfaces. An NDAA 848 compliant ECU is also available. The A99HF produces up to 6.5 kilowatts at 7000 RPM and supports hybrid boost for high-demand phases such as climb or sprint.
Specifications:
| Weight: | 8.4 kg (18.5 lbs) |
| Displacement: | 101.4 cc (6.0 ci) |
| Power Output: | 6.5 kW (8.7 HP) at 7000 RPM |
| Generator Output: | 650W (800W intermittent) |
| Fuel Consumption: | 460 g/kW-hr (0.83 lb/hp-hr) |
| Fuel Type: | VP C9 50:1, JP5, JP8, Jet A |
| Interfaces: | CAN, Serial |
