Liberty Lifter

military's Defense Advanced Research Projects Agency (DARPA) launched in mid-2022 to develop a low-cost seaplane that would use the ground-effect to travel long distances.

Unlike Soviet-era ekranoplan designs, the Liberty Lifter aircraft is expected to operate in moderate to rough sea states and be able to fly out of ground effect.

DARPA launched the project in mid-2022, wanting a plane that could lift large, heavy loads by skimming the water in ground effect, but was also capable of operating at mid-altitudes of up to 10,000 feet (3,000 m). Such a vehicle would also be able to land and take off from the water, making it runway-independent.

In February 2023, DARPA awarded contracts to two contractors to develop their own plans. One was General Atomics Aeronautical Systems (GA-ASI), partnering with Maritime Applied Physics Corporation; their design features a twin hull and a mid-wing, powered by twelve turboshaft engines. The other participant was Boeing subsidiary Aurora Flight Sciences partnering with Leidos subsidiary Gibbs & Cox and with ReconCraft; their design is a monohull with a high-wing, primarily relying on eight turbine engines.

The initial Phase 1 GA-ASI group contract was for about $8 million for the next six months, with an option for another 12 months potentially growing to a total of $29 million. The Aurora contract was for about $5.6 million.

In July 2023, DARPA exercised options on both teams’ initial proposals, and awarded GA-ASI an additional $21.5 million, and Aurora about $19.5 million, to fund continued development efforts.

Specifications for the craft include the ability to fly less than 100 feet (30 m) from sea level to harness ground effect, but also the ability to climb as high as 10,000 feet (3,000 m) above mean sea level. It should have a ferry range of 6,500 nautical miles (12,000 km), and be able to take off and land in Sea State 4, but sustain on-water operations up to Sea State 5, while meeting the United States Department of Defense heavy lift requirements of carrying 90 tons and having a low-cost design and construction philosophy. Such a craft would be similar in size and capacity to the Boeing C-17 Globemaster III.

Final designs for Phase 1 are expected by mid-2024. The winning proposal will proceed to Phase 2, which includes further design work, and the building and testing of a full-size prototype, which will then continue to flight-testing within roughly five years.