Aurora Flight Sciences will continue designing an experimental heavy cargo seaplane for the U.S. military, which has now officially dropped General Atomics’ pitch for the Liberty Lifter aircraft program.
The Pentagon announced Thursday that Aurora, a subsidiary of Boeing based in Manassas, Virginia, has received an $8.3 million contract modification to keep working on its mobility seaplane design.
The Defense Advanced Research Projects Agency in February 2023 selected Aurora and General Atomics for the program, officially called the Liberty Lifter Seaplane Wing-in-Ground Effect.
DARPA originally envisioned Liberty Lifter as having about the same size and capacity of a massive C-17 Globemaster mobility aircraft, but has since scaled back the demonstrator program to about the size of a C-130 Hercules. But DARPA’s budget documents for fiscal 2025 show that a future Liberty Lifter aircraft could be built to roughly a C-17′s scale once there’s proof the concept works.
The Globemaster’s wingspan is more than 169 feet, its length 174 feet and its height about 55 feet. It can carry 170,900 pounds of cargo. In comparison, the Hercules’ wingspan is more than 132 feet. The longest of the variants is about 97 feet, and the tallest is about 38 feet. One variant can carry a payload of 44,500 pounds.
Liberty Lifter is also intended to be able to take off and land in sea state 4, or weather conditions that produce waves of up to about 8 feet, and could sustain operations even in sea state 5, or rough waves of up to 13 feet.
General Atomics proposed a version of Liberty Lifter with an unorthodox twin-hull design, which was intended to make the aircraft more stable on water. Concept art of General Atomics’ design showed the plane’s noses would have lifted up to deploy cargo and allowed vehicles to directly roll onto a beach.
Aurora’s design was closer to a traditional flying boat aircraft with a single hull and high wings that angled down at the ends. In January, Aurora released an image of its updated design, which had moved the aircraft’s floats to its wingtips and changed its tail design. Aurora said the new tail, which would be shaped like the symbol for pi, would better accommodate the plane’s aft cargo door.
DARPA’s Liberty Lifter manager, Christopher Kent, told Defense News in a statement that the program needed to move efficiently “to create transformational change,” and that General Atomics’ design could not meet its ambitious goals.
“When we reached the point where we realized only one performer was meeting our aggressive schedule and technical goals, we streamlined the program to continue to deliver innovation” as soon as possible, Kent said when asked why DARPA did not continue including General Atomics.
C. Mark Brinkley, a spokesman for General Atomics Aeronautical Systems, said in an email to Defense News that the company wants to continue working with DARPA on other programs and wishes the Liberty Lifter program success.
“I think we all recognize the Liberty Lifter concept represents a real technological shift for future combat operations, and we made a strong proposal informed by a lot of experience and expertise,” Brinkley said. “You always want to win and keep working on these things, but more than that we just want to see the program thrive and deliver a unique capability for the warfighter and the nation.”
Aurora Flight Sciences declined to comment on the contract modification. The company is working on the aircraft with ReconCraft, a shipyard based in Oregon that has expertise with maritime manufacturing, and Leidos subsidiary Gibbs and Cox, a naval architecture and marine engineering company.
Aurora will now continue to design its Liberty Lifter and reduce its risk as it gets ready for a preliminary design review in early 2025, DARPA said. If the design review is successful, DARPA noted Aurora will continue refining the design and then build its Liberty Lifter.
After that point, DARPA said, Aurora will float, fly and then demonstrate Liberty Lifter’s capabilities, with its first flight intended to occur in late 2027 or early 2028.
Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.