The Defense Advanced Research Projects Agency has ended its experiment to create a heavy cargo seaplane.
The nearly three-year-old Liberty Lifter program was intended to design and build and possibly float and fly a long-range, low-cost seaplane that could take off and land in rough seas.
DARPA said in 2023 that it wanted the plane to have roughly the same size and capacity as a C-17 Globemaster, which can carry more than 170,000 pounds of cargo such as M1 Abrams tanks.In a statement, DARPA confirmed it had concluded the Liberty Lifter program in June.Weve learned we can build a flying boat capable of takeoff and landing in high sea states, program manager Christopher Kent said.
The physics make sense.
And weve learned we can do so with maritime building techniques and maritime composites.But DARPA said it will not move forward with building an aircraft, which would only be a demonstrator.We think our findings validate the hypothesis we had going in: you can build platforms that fly significantly cheaper and at significantly more locations than we do today, Kent said.
This opens up a pathway for next generation aircraft to be built using far more efficient construction technologies.DARPA also said more work needs to be done to blend maritime construction with aircraft certification.In a statement, Aurora said the technology it developed through the program will be used in years to come.Through the Liberty Lifter program, we were able to show the viability of the design and the feasibility of novel manufacturing techniques, Aurora said.
Aurora is proud of the technical advancements we made through the preliminary design of Liberty Lifter, and we expect to apply these learnings to future programs.Contracted to General Atomics Aeronautical Systems (GA-ASI) and Boeing subsidiary Aurora Flight Sciences, the plan was to first build a demonstrator aircraft about the size of a C-130 Hercules capable of lifting 50,000 lb (22,600 kg), followed by an eight-engine, full-size version comparable in payload to a Boeing C-17 Globemaster III, which has a capacity of 170,000 lb (77,000 kg), and with a ferry range of 12,000 nautical miles (13,809 miles, 22,224 km).In addition to sheer size, the Liberty Lifter was meant to be able to take off and land in State 4 sea conditions (waves 1.25 to 2.5 m/4 ft 1 in to 8 ft 2 in) and handle on-water operations in State 5 (waves 2.5 to 4 m/8 ft 2 in to 13 ft 1 in).
It was also supposed to be a showcase for new materials and use shipbuilding rather than aircraft manufacturing techniques to keep costs down and speed production.
Producing an aircraft that doesnt require runways or shipping ports was also attractive.DARPA hoped creating a cargo seaplane could lead to new opportunities for the military and commercial organizations to conduct fast logistics missions, as well as develop innovative manufacturing techniques and materials to bring down the cost of building large aircraft.The idea was to build a seaplane using advanced composite materials that had enough range and payload capacity to carry out fast logistics missions as well as assisting in rescue and disaster relief efforts.
Using the WIG effect that greatly increases lift at low altitudes by essentially trapping a cushion of air under the wings, the goal was to create a series of seaplanes of unprecedented cargo capacity.DARPA said it restructured the Liberty Lifter program in late 2023 to pull forward technical risk reduction activities.
In early 2024, DARPA announced it had dropped General Atomics from the program and continued with Auroras pitch.Aurora Flight Sciences tweaked its original Liberty Lifter design to move floats to its wingtips and adjust its tail to better accommodate its aft cargo door Aurora Flight SciencesAurora and DARPA used simulations and tests of scaled models to demonstrate the seaplanes technical design, as well as building and stress-testing examples of the new methods and materials intended for the plane.Those simulations and tests showed the concept was viable, DARPA said, and the novel building methods one day could help dramatically cut the cost of building large aircraft.
The agency is now working with industry and other stakeholders in the Defense Department to figure out how to rapidly field these technologies in other forms.DARPA confirmed it spent about $98 million in all on Liberty Lifter.Sources: AirForceTimes; New Atlas