HFDI-350
The Orbital UAV HFDI-350 is a two-stroke twin-boxer heavy-fuel engine that has been designed to meet the requirements of heavy-lift and long-endurance Group 3 UAV mission profiles in demanding environments, delivering 28.4 hp with low levels of vibration.
The advanced propulsion system features Orbital’s FlexDI fuel injection technology, atomizing fuel to smaller droplets for a cleaner burn. FlexDI offers >30% lower cruise fuel use and high specific power, and also meets MIL-STD-1474D specifications for noise.
The MIL-STD-810H qualified engine offers high levels of onboard electrical power to support advanced sensors, communications systems and edge computing equipment.
Specifications:
| Weight: | ~16.7kg (includes ECU, mount, pumps, harness, propeller) |
| Power: | 28.4hp (20.9kW) @ 6500 RPM |
| Fuel Consumption (BSFC): | ~325 g/kWh @ typical cruise |
| Max Operating Altitude: | 20,000 ft AMSL |
| Operating Temperature: | -30 to 55 °C including start |
| TBO: | 500 hrs |






