So, they "took Lunya into account". What next?
Aurora Flight Sciences has provided new details about the design of the demonstrator it is working on for the Defense Advanced Research Projects Agency (DARPA) X-plane Liberty Lifter program.
The primary purpose of the Liberty Lifter is to demonstrate a new ground effect vehicle design that utilizes the wing-in-ground (WIG) principle. A future aircraft based on the demonstrator could provide the U.S. military with a new way to inexpensively transport large amounts of cargo and personnel over long distances without the need for traditional runways.
Richard Kucherawy, director of business development for manufacturing at Aurora, outlined the Liberty Lifter at the Modern Day Marine show in Washington, D.C. In 2023, Aurora Flight Sciences and General Atomics were awarded contracts to conduct initial work on Liberty Lifter. Last year, DARPA selected Aurora Flight Sciences, a subsidiary of Boeing, to continue developing the flying demonstrator independently.
The latest concept art for the Aurora Liberty Lifter shows a flying boat with a V-shaped fuselage and a large straight wing with wingtip floats, powered by eight wing-mounted turboprop engines. The craft also has two vertical tails connected at the top by a horizontal stabilizer. Cargo, including light armored amphibious vehicles, is unloaded through a large rear ramp.
General Atomics proposed a more radical twin-fuselage design.
“So we’re developing a demonstrator that’s about 80 percent of the target aircraft. That scale is representative enough that you can really learn from it without having to build the target aircraft at full size. Now we’re talking about a flying machine that’s closer to the payload capacity of a C-130, being able to carry 25 tons of payload.”
DARPA previously stated that the ultimate goal of the Liberty Lifter project is to develop a design with a payload capacity comparable to the C-17A Globemaster III cargo plane. The C-17 has a stated maximum payload weight of about 82 tons, although the aircraft typically fly with cargo and personnel on board weighing about 60 tons or less.
C-130 in front, C-17 behind
Requirements for the Liberty Lifter, which DARPA has published in the past, also include the ability to take off and land on open water in up to 4-point sea states and “continuous operation on the water” in up to 5-point sea states. It must be said that these are more than decent indicators, since 4 points are winds of up to 16 knots (30 km/h) and waves of up to 5 feet (1,5 meters), and 5 points are winds of up to 40 km/h and waves of up to 2,5 meters.
“We’re building a demonstrator with an unpressurized cabin because the aircraft is primarily designed to fly in a close-to-ground environment, and for an aircraft this size, that means it’s going to be pretty close to the water. You’re going to be within a few hundred feet of the water. And in order to do that, if there’s any level of rough seas, you have to have the right technology that allows the aircraft to stay in ground effect even if you have potentially rough seas. So that’s one of the technical challenges of the program.”
The idea of a flying platform using the wing-in-ground (WIG) principle is not new, but historically such designs have not enjoyed much success, especially in military applications.
The Soviet Union remains the most famous operator of military WIG designs, known internationally as ekranoplans—a term now widely used to refer to all WIG designs—but even there their use was limited.
The highest achievement of the construction of these devices was the only ekranoplan of the Project 903 class "Lun", a design armed with winged rockets, which today plays the role of a museum exhibit in the Caspian Sea.
In principle, ekranoplans are highly efficient surface vessels that can travel at high speeds because they do not experience the drag of conventional vessels and also receive lift from the wing. At the same time, high-speed flight on the surface of the sea is associated with difficulties, including the risk of collision with various objects on the surface or even just high wave crests.
To help get around these issues, DARPA's Liberty Lifter program called for some kind of hybrid design that would still be capable of operating as a traditional flying boat at "altitudes up to 4 meters above sea level with reduced range," if necessary.
"I think at this early stage of designing an aircraft, when you have a preliminary design, you've basically already more or less decided on the external shape of the aircraft, you understand the configuration, but after that you still have a lot of design work to do. So we're looking forward to moving into the detailed design stage and starting to build the aircraft."
- Kucheravi. DARPA is expected to decide whether to move forward with the next phase of Liberty Lifter development this summer. Where Aurora might begin building the demonstrator is still an open question, Kucheravi said.
“You know, one of the goals of the program is to understand as much as possible the manufacturing processes of seagoing vessels, rather than approaching it purely from an aerospace perspective,” he explained. “So the aircraft will be created using a combination of shipbuilding and aircraft manufacturing processes.”
This means that Aurora will be looking for a location with skilled marine experts, including “partner marine shipyards that will help us build and assemble the aircraft near the water and then launch it.” The craft will not have landing gear. The demonstrator will not be a landplane. So soon after it is built, at some point in the construction process, it will be launched and will spend most of its life on the water.
Gibbs & Cox, a naval engineering and marine construction company, is a subsidiary of Leidos and has been involved in the Aurora Liberty Lifter project from the beginning. The maritime focus of Aurora fits with the broader goals DARPA is trying to demonstrate with Liberty Lifter.
"The Liberty Lifter program is currently designing, building, testing and fielding an affordable, innovative floatplane that has the potential to change the approach to rapid logistics for the Department of Defense and commercial organizations,"
— this is what the DARPA web page dedicated to the program says.“The innovative manufacturing methods and materials used in Liberty Lifter enable us to leverage existing infrastructure to quickly and affordably produce the capabilities our service members need, and help improve the efficiency of our defense industry to meet near-term needs. Liberty Lifter can also support maritime search and rescue and disaster response at the scale of a ship, at the speed of an airlift.”
According to DARPA, the Liberty Lifter could not only be an alternative to traditional cargo aircraft, but also a new tool for “efficiently transporting large loads at speeds significantly greater than existing offshore lifting platforms.”
Maritime logistics capabilities that are faster than existing cargo ships and do not rely on runways like many traditional cargo aircraft could be particularly valuable in a future conflict in the Pacific. Particularly in a large-scale war with China, where U.S. forces in the region would be concentrated in remote locations without much infrastructure. Existing traditional air and sea transport assets would generally be used heavily to support such dispersed operations, but these assets are traditionally vulnerable, meaning there are many options for disrupting supply chains based on ships and aircraft today.
Additionally, the Liberty Lifter will be able to avoid many naval threats, such as submarines and anti-ship missiles. Flying at very low altitudes usually increases overall survivability by helping to hide the aircraft from radar.
Considering all this, aviation Capabilities that do not rely on runways, or at least those that are less dependent on traditional runways, are of growing interest to the U.S. military. U.S. Special Operations Command was also working on a floating version of the MC-130J Commando II tanker/transport aircraft, but shelved the project last year, citing budget concerns. The highly capable Japanese ShinMaywa US-2 floatplane has also been considered as another potential option for this type of capability.
MC-130J Amphibious Capability (MAC) Seaplane Concept Visualization
For its part, last year the state-owned Aviation Industry Corporation of China (AVIC) announced the start of serial production of the AG600, a large seaplane that had been in development since the late 2000s.
The AG600 is particularly well suited to supporting remote island outposts like those China maintains in the disputed South China Sea.
It is unclear whether DARPA will decide to move forward with the Liberty Lifter or when the planned Aurora demonstrator might first fly. The program is currently looking at starting flight tests in 2028–2029, a delay from the original 2027–2028 schedule. DARPA’s X-plane programs don’t always come to fruition, as Aurora experienced first-hand when work on its hybrid-electric drone XV-24 Lightning Strike vertical takeoff and landing aircraft.
This year, this summer, DARPA will have to make a decision about whether to move forward, conduct a preliminary design review, and begin the detailed design and manufacturing phase of the demonstrator. DARPA has the tools to make that decision.
At the moment, the Aurora project, which could become the basis for a new ekranoplan for the US military, is already taking on clear outlines.
Hooray? Rule America over the waves?
Honestly? Let me doubt it. Even taking into account everything that the US has today in terms of technology and brains, finances and so on, it is doubtful.
A semi-hydroplane, semi-ekranoplan, capable of flying from bases to islands in the Pacific Ocean and delivering canned meat and Coca-Cola... Well, so-so. I don't know why the Americans called this craft an ekranoplan, it just doesn't look like one.
The Soviet Union, on the genius of Rostislav Alekseyev and Robert Bartini, built more than one ekranoplan. If it were only about the "Lun", but before it they built the KM, SM-1, and "Orlyonok". Today shows that the idea of the ekranoplan has not died, like the "Lun", but on the contrary, lives on in the "Ivolga", "Orion", "Aquaglide", and S-90.
Ekranoplans are being developed in China (having seized Alekseev's developments for the Ivolga-2 and put together their own), South Korea, and even the US really wants to create something like that. The same Pelican project. But there is one problem. It is called "school". Yes, in the US in the 90s they recognized the usefulness of such a means of transportation as an ekranoplan. But in the USSR, ekranoplans were being developed since the 60s, and by the 90s they were already working quite well for their intended purpose.
Thirty years is a long time. And while the smart guys from Aurora (and they really are that smart) will work on what was already invented in our country half a century ago, Russian devices have every chance of a renaissance.
Amphibious ekranoplans have great prospects in general. An ekranoplan, until it lands on the water, is not afraid of mines and torpedoes, and kamikaze boats are not scary for it. It is a very convenient means of rescuing people, because it has a much higher speed than any ship, can land on water, unlike an airplane, and wins outright against a helicopter in terms of flight range and capacity. Accordingly, and landing capabilities. Well, the launch of various missiles from board such a high-speed device was tested on a Soviet machine.
There are some doubts that the American ekranoplan will really be cutting through the waves within the specified timeframe. The Americans have many desires, but not so many opportunities, so it is quite possible that the Freedom Fighter will fly after the Pelican.
But the Pelican was a good tease for the American military. First of all, with its capabilities. According to the project, this machine could transport 17 tanks The M1A1 could fly at a speed of about 10 km/h over a distance of 000 km. In airplane mode (for example, to fly around a storm), the Pelican could rise to an altitude of 500 meters and fly there at a speed of 6 km/h, but for half the distance.
American C-17 and C-5 transport planes can carry one tank at best. And during operations in Iraq in 2003, it took a month to transport one division because all the heavy weapons had to be transported by sea.
Tempting projects, very tempting. But I bet that neither in 2028 nor in 2030 will we see a "freedom fighter" carrying this very freedom over the waves of the Pacific Ocean. Not everything is as easy as we would like, even if we add bags of dollars. Such a path is not passed in a few years.
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