Waves of Change: Diverse directions in DOD Seaplane Planes

While another programme aiming for a similar result appears to have stagnated, one of the U.S. defence department's efforts to create a capacity to deploy large numbers of personnel and material to coastal regions by air made a minor step ahead last week.

Aurora Flight Sciences, a Boeing subsidiary, received an $8.3 million contract modification on May 9 to advance Phase 1b of DARPA's Liberty Lifter seaplane program. Meanwhile, SOCOM has temporarily halted its three-year initiative to equip the Lockheed MC-130J with water take-off and landing capabilities, citing the project's progression towards the preliminary design review stage, set for early 2025.

Large floats attached to former Commando Solo aircraft have been investigated for their economic and technological viability as part of the MC-130J Amphibious Concept (MAC) programme. Test flights were initially scheduled for 2022 but were postponed because of a severe technological problem.

“We might not be breaking physics [but] this is hard engineering.” – Former SOCOM PEO for fixed wing, Col. Ken Keubler.

The two Liberty Lifter rival projects will likewise need to deal with some of these issues, even though their methods for obtaining ostensibly comparable capabilities differ. Although it can fly up to 10,000 feet, the planned aircraft is expected to function mostly as a wing-in-ground effect platform near the water's surface. When the project was initially announced, Dr. Christopher Kent, the programme manager at DARPA, stated that the programme will be able to explore "a relatively large design space" because the two consortia are adopting radically different approaches.

Aurora is in charge of a group that comprises, the maritime engineering company, Gibbs & Cox, owned by Leidos, and the shipyard Recon Craft, located in Oregon. With eight turboprops positioned on a high wing, a rear cargo door, and floats fastened to the wingtips, their concept is similar to conventional flying-boat designs. The competing group, which includes the naval technology company Maritime Applied Physics Corp. of Baltimore along with General Atomics Aeronautical Systems, plans to build a twin-hulled aircraft with a mid-wing and twelve turboshaft engines.

Col. T. Justin Bronder, 2025 SOCOM PEO, explained the MAC stop at a May 7 presentation to the SOF Week conference by stating that although the capability was still sought by the command, the programme was not now cost-effective. The C-130 can airdrop personnel and supplies in its standard configuration, as AWST pointed out when the programme was launched in 2021. Therefore, this level of modification would not always be necessary to use the platform for a coastal resupply mission. On the other hand, if fuel could be positioned beforehand, landing on water might provide a considerable range extension for trips over oceans.

DARPA states on the website for its Liberty Lifter programme that the project's goal is to develop a platform for disaster response, search and rescue, and logistics that combines "the scale of ships with the speed of air transport". The objective is to develop an aircraft approximately the size of a C-17 with four times the cargo capacity of a C-130J, emphasizing affordability as a crucial requirement for the project. During the program's introduction, the agency stated that it "anticipates teaming with one or more DoD Service and international partners" for the production of a full-scale demonstrator in phase two of the initiative.