DARPA Funded Two Wing in Ground Effect Transport Planes

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

The planned Liberty Lifter demonstrator will be a large flying boat similar in size and capacity to the C-17 Globemaster III transport aircraft. Goals include takeoff 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.

“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,” said DARPA Liberty Lifter Program Manager Christopher Kent. “The two teams have taken distinctly different design approaches that will enable us to explore a relatively large design space during Phase 1.”

“Liberty Lifter will use low-cost manufacturing akin to ship fabrication in building a highly innovative seaplane capable of meeting DoD heavy lift requirements [100+ tons] that operates with runway and port independence.”

General Atomics was awarded $8 million cost-plus-fixed-fee contract award in support of DARPA’s Liberty Lifter program in November for the work, the company announced Wednesday. The contract could include options brining the value 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. Aurora, a Boeing subsidiary, was awarded $5.7 million on Jan. 27, with options that could grow the contract to $27 million.

The 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.

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.

As scheduled, Phase 1 will transition into Phase 2 in mid-2024 with continued detailed design, manufacturing, and demonstration of a full-scale Liberty Lifter X-Plane. DARPA anticipates teaming with one or more DoD Service and international partners for those activities and further development of the Liberty Lifter concept into an operational vehicle.

History of Wing in Ground Effect Planes

The Caspian Sea Monster was an experimental ekranoplan, developed at the design bureau of Rostislav Alexeyev.

It was actually built and flown.

The Ekranoplan had wingspan of 37.6 m, length – 92 m, maximum take-off weight – 544 tons. It was the largest airplane until the Ukrainian An-225 was built. Ekranoplan was designed to fly at an altitude of 5-10 meters in order to utilize the ground effect.

The Boeing Pelican ULTRA (Ultra Large TRansport Aircraft) was a proposed ground effect fixed-wing aircraft under study by Boeing Phantom Works. Intended as a large-capacity transport craft for military or civilian use, it would have a wingspan of 500 feet (150 m), a cargo capacity of 1,400 tons (1,300 metric tonnes), and a range of about 10,000 nautical miles (18,000 km). Powered by four turboprop engines, its main mode would be to fly in ground effect 20–50 ft (6–15 m) over water, though it would also be capable of overland flight at an altitude as high as 20,000 ft (6,100 m) albeit with a decreased range of about 6,500 nautical miles (12,000 km). It would operate from conventional runways, with its weight distributed over 38 fuselage-mounted landing gears with 76 wheels. The Pelican was never built.

6 thoughts on “DARPA Funded Two Wing in Ground Effect Transport Planes”

  1. More money down the rat hole – the military industrial complex binging on the tax payer money for truly dopey stuff. Apparently, common sense is in short supply in the DoD.
    A really easy to spot and destroy target that costs a fortune while being full of lots of really expensive equipment. What could possibly go wrong.

  2. The main problem with these airplanes is high maintenance costs due to corrosion and the development costs of the project
    Also, probably not fitted for regular flight in certain routes due to wave size and storms

    For military purposes the Boeing Pelican ULTRA would literally single-handedly provide equipment to take a country down with a mass scale assault with unmatched speed and range, for comparison the largest airplane in the world the Antonov An-225 can carry 4 M-1 Abrams
    From wikipedia:
    The Pelican has a maximum payload weight of 2,800,000 pounds (1,400 short tons; 1,270 metric tons),[21] which allows an army to transport 70 heavy expanded mobility tactical trucks (HEMTTs) or 52 M270 multiple launch rocket systems (MLRSs). It can carry 17 M-1 Abrams tanks in five rows of three abreast and one row of two abreast

    • Not exactly stealthy, though. It’s a high value military target, like an aircraft carrier, only not remotely as kill resistant. If they build one, weapons to take one out would be a fraction as expensive.

      You’d be betting your whole attack on a mine not being in the relatively observable flight path.

  3. fly like an arrow, land, and taxi to turn, or build it to fly higher and then you need to wonder if it wouldn’t have been better off flying all along.

  4. The upside is that ground effect planes can be absurdly large, they scale well. So they do look good for the flying equivalent of a cargo ship. Or maybe a cruise ship; There might be a market niche for trans-oceanic flights that take several days, but are cheaper and more comfortable than regular airliners.

    The downside is that, unless you’re only going to fly them in good weather, they have to be absurdly large, to avoid being taken out by a bad wave. And you lose a lot of the advantage if you demand that they be capable of flying in a non-ground effect mode in bad weather. They’re also not nearly as fast as airplanes that can flight at great altitude, where the air is thinner.

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