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Cobra Aero's hybrid electric power unit is built around a heavy-fuel piston engine.
On the heels of a contract from the Royal Australian Navy for its Transwing P4 vertical-takeoff-and-landing uncrewed aircraft system, U.S. startup PteroDynamics has unveiled plans to develop a hybrid-electric version of its larger P5.
Colorado Springs-based PteroDynamics has partnered with Cobra Aero to develop the hybrid-electric variant. This will use Hillsdale, Michigan-based Cobra’s A99HF-EPU, a heavy-fuel hybrid unit producing 9 kW of electric power for propulsion and payloads.
The three-cylinder, two-stroke A99HF-EPU is liquid-cooled to support operations in hot, high and austere environments. The powerplant can operate on a range of commercial and military fuels, Cobra says.
The P4 has a maximum takeoff weight of 41 kg (89 lb.) and can carry payloads of up to 6.8 kg. The P5 weighs 145 kg and can carry payloads up to 23 kg over a range of 740 km (400 nm). The Royal Australian Navy (RAN) has an option to acquire the P5 variant in 2027.
To transition from wingborne cruise to vertical flight, the Transwing tilts and folds its wings back along the fuselage, taking off and landing like a quadrotor drone. PteroDynamics was founded in 2017 and first demonstrated the Transwing for the U.S. Navy in 2022.
PteroDynamics demonstrated the P4 to the RAN in April, showcasing long-range shore-to-ship, ship-to-ship and ship-to-shore cargo delivery missions. The platform was previously validated with the U.S. Navy during a 2024 Pacific Rim exercise.
- Additional reporting by Chen Chuanren
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