https://www.defensenews.com/air/2023...n-land-at-sea/
DARPA wants a heavy cargo plane that can land at sea
WASHINGTON — DARPA has tapped two companies to design, and possibly build, an experimental seaplane that can transport large amounts of cargo on the water.
General Atomics and Aurora Flight Sciences, a subsidiary of Boeing, will develop their own competing designs for DARPA’s mobility seaplane program, DARPA said Wednesday. DARPA has dubbed this program the Liberty Lifter Seaplane Wing-in-Ground Effect, or Liberty Lifter for short.
DARPA wants this aircraft to be a long-range, low-cost aircraft around the same size and capacity as the C-17 Globemaster, which can carry more than 170,000 pounds of cargo, including a 69-ton M1 Abrams main battle tank, armored vehicles, trucks or trailers…..
And DARPA has set some ambitious goals for the Liberty Lifter’s sea capabilities.
The seaplane DARPA envisions would be more robust than some of the Navy’s in-water capabilities. Small boats, for example, are typically limited to so-called sea state 3 conditions, where waves are about four feet high. But the Liberty Lifter would be required to take off and land in sea state 4, which sees waves of up to about eight feet.
At sea state 5, where waves are considered rough and reach 13 feet, these planes would still be asked to sustain operations. Sea state 5 is the point at which conditions start to threaten the Navy’s ability to conduct resupply missions at sea between auxiliary ships and warships.
The Liberty Lifter also should be capable of extended flight close to the water, DARPA said.….
The two companies vying to create the Liberty Lifter took markedly different approaches, according to concept art DARPA released.
Aurora Flight Sciences, which is working with marine engineering company Gibbs & Cox and marine vessel design company ReconCraft, designed a more traditional “flying boat” aircraft, as DARPA called it.
Aurora’s design has a single hull, high wings, wide horizontal stabilizers on its tail, and eight turboprops. Its wings would also angle down, though Aurora said they would not touch the water. Aurora said its plane would be able to carry two Marine Corps amphibious combat vehicles, or six 20-foot container units.
General Atomics, along with naval engineering and design firm Maritime Applied Physics, proposed a twin-hull, mid-wing design, which DARPA said is intended to optimize its stability on water. It would have 12 turboshaft propeller engines. The art also shows stabilizers on its dual noses.
Instead of loading or unloading cargo from an aft door and ramp, as is the case for the C-17, General Atomics’ concept art shows its plane’s noses lifting up and vehicles deploying directly from the front, down the ramps to a beach.
DARPA in November awarded General Atomics an $8 million cost-plus-fixed-fee contract for the Liberty Lifter program, and General Atomics said its award has the potential to grow to up to $29 million. Aurora’s contract, which DARPA awarded Jan. 27, was for $5.7 million, and could grow to more than $25 million if all options are exercised….
https://en.wikipedia.org/wiki/Boeing_Pelican