US DARPA awards contracts to develop designs for Liberty Lifter Seaplane

News, US February 3, 2023 , by IRIA No Comments

U.S. Defense Advanced Research Projects Agency (DARPA) selected General Atomics and Aurora Flight Sciences teams for DARPA’s Liberty Lifter X-Plane Program. The first phase will define the seaplane’s design and capabilities, DARPA announced on February 1, 2023.

According to the DARPA statement, “Two teams — General Atomics working with Maritime Applied Physics Corporation and Aurora Flight Sciences working with Gibbs & Cox and ReconCraft — will develop designs for DARPA’s Liberty Lifter Seaplane Wing-in-Ground Effect full-scale demonstrator.”

DARPA Liberty Lifter Program Manager Christopher Kent said, “We are excited to kick off this program and looking forward to working closely with both performer teams as they mature their point-of-departure design concepts through Phase 1.

“The two teams have taken distinctly different design approaches that will enable us to explore a relatively large design space during Phase 1,” Kend added.

The Liberty Lifter program of DARPA aims to demonstrate advanced operational capability by designing, building, floating, and flying a long-range, low-cost X-Plane “capable of a seaborne strategic and tactical heavy lift.”

The aircraft would operate efficiently in ground effect (< 100 feet above the surface), sustain flight altitudes up to 10,000 feet mean sea level (MSL), and enable efficient theater-range transport of large payloads at speeds far exceeding existing sea lift platforms.

U.S. energy and defense corporation General Atomics team has selected a twin-hull, mid-wing design to optimize on-water stability and seakeeping. It employs distributed propulsion using twelve turboshaft engines. While Aurora Flight Sciences’ design more closely resembles a traditional flying boat, with a single hull, high wing, and eight turboprops for primary propulsion, according to DARPA.

*^{General Atomics-Aeronautical Systems, Inc. Liberty Lifter concept. (Image Credit: General Atomics)}*

The planned Liberty Lifter demonstrator will be a large flying boat similar in size and capacity to the C-17 Globemaster III transport aircraft. DARPA highlighted that the intended goals include, “take off and land in Sea State 4, sustained on-water operation up to Sea State 5, and extended flight close to the water in ground effect with the capability to fly out of ground effect at altitudes up to 10,000 feet above sea level.”

According to the DARPA statement, “During Phase 1, DARPA will work with both performer teams and Department of Defense stakeholders to refine the Liberty Lifter designs with particular attention to operational needs and operating concepts. The Phase 1 contract awards are for an 18-month period of performance with six months of conceptual design work and nine months of design maturation culminating in a preliminary design review. There will be an additional three months for manufacturing planning and test/demonstration planning reviews.”

Phase 1 is expected to be transitioned into Phase 2 in mid-2024 with continued detailed design, manufacturing, and demonstration of a full-scale Liberty Lifter X-Plane. DARPA aims to team up with the U.S. Department of Defense Service and international partners for further development of the Liberty Lifter concept into an operational vehicle.