DARPA picks General Atomics to design long-range, heavy-lift seaplane that operates for weeks in rough seas

Nov. 29, 2022
Liberty Lifter seaplane will have extended operations in high sea states, be affordable to produce, and have complex flight and sea-surface controls.

ARLINGTON, Va. – U.S. military researchers needed a futuristic seaplane able to operate in rough seas for weeks at a time, and carry payloads as heavy as 45 tons for distances between 4,000 and 6,500 miles. They found their solution from General Atomics Aeronautical Systems Inc. in Poway, Calif.

Officials of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., announced an $8 million contract to General Atomics on Friday for the Liberty Lifter program to develop a heavy-lift, long-range seaplane that operates efficiently at very low altitudes in ground effect.

For the Liberty Lifter project, General Atomics will focus on designing a seaplane with extended maritime operations in high sea states that is affordable to produce, and that involves complex flight and sea surface controls.

The Liberty Lifter long-range seaplane will provide smooth operations in ground effect in waves that are four to eight feet high. Ground effect describes the added aerodynamic buoyancy produced by a cushion of air below an aircraft moving closely to the ground or surface of the water.

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General Atomics will try to achieve smooth flight while flying over waves as high as eight to 13 feet, with high lift at low speeds to reduce wave impact loads during takeoff and landing in waves from 4 to 8 feet high. The seaplane is expected to accommodate wave impact loads and be able to operate in high-traffic areas, and operate at sea for weeks at a time with long periods between land-based maintenance.

DARPA researchers are emphasizing low cost, easy-to-fabricate designs, with Liberty Ship-style manufacturing. The seaplane also should have complex aero and hydrodynamic interactions during takeoff and landing, with advanced sensors and controls to avoid rogue wave impacts.

The Liberty Lifter seaplane should be able to take off and land in waves from four to eight feet high; fly in ground effect above waves from 8 to 13 feet high; fly at altitudes from ground effect to 10,000 feet, and operate for four to six weeks at a time carrying payloads of at least 90 tons.

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On-water amphibious payload deployment and retrieval should be via nose and tail ramps; the seaplane should be able to carry at least two U.S. Marine Corps Amphibious Combat Vehicles, and cargo in 20-foot container units.

General Atomics designers will use high-performance computing and multi-disciplinary analysis and optimization tools to model and analyze complex aerodynamic and hydrodynamic interactions; focus on affordable design and manufacturing approaches; use novel manufacturing approaches; and use industry best practices from commercial high-speed vessels.

The program consists of a three-phase developmental cycle with each phase building on the previous phase. For more information contact General Atomics Aeronautical Systems online at www.ga-asi.com, or DARPA at www.darpa.mil.

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