The United States Defense Advanced Research Projects Agency has launched Liberty Lifter, a research program aimed at developing a military transport seaplane capable of lifting very large heavy loads over long distances.
The goal of the Liberty Lifter program is to develop a “low-cost, long-range X-aircraft” with better maneuverability and operational capabilities than existing transport aircraft.
The double-hulled aircraft would not require a runway and will use the wing-in-ground (WIG) effect, a concept used by Soviet-era aerospace engineers in the 1980s to develop large cargo seaplanes. WIG was later studied by the Defense Advanced Research Projects Agency (DARPA) and Boeing engineers in the United States.
As reported by IEEE SpectrumDARPA is offering up to $15 million for two initial concepts, with hopes that at least one will pass critical system-level design review by 2025. First flight of a Liberty Lifter prototype could begin from 2027.
an initial information request was released by DARPA for the Liberty Lifter last year.
The WIG effect is an aerodynamic principle by which the drag on an aircraft’s wings is reduced near a fixed surface, whether at sea or on land. The modified airflow provides lift to the craft, allowing it to hover over long distances, even when traveling below climb speed.
Alexander Walan, Liberty Lifter Program Manager at DARPA, said: “This first phase of the Liberty Lifter program will define the seaplane’s range, payloads and other parameters. The innovative advancements envisioned by this new DARPA program will feature an X-plane demonstrator that provides warfighters with new capabilities during extended maritime operations.
The increased energy efficiency enabled by the WIG phenomenon will be essential for the Liberty Lifter program. Aircraft specifications include a range of over 7,500 km (4,660 miles), with payloads of over 100 tons.
Along with DoD travel and payload requirements, the concept(s) will need to demonstrate deep sea takeoff/landing, extended flight capability out of ground effect/obstacle avoidance, and manufacturing techniques and design choices. Low cost.
The announcement comes shortly after the launch of DARPA’s Revolutionary Aircraft Control Program with New Effectors (CRANE), in partnership with BAE Systems and Georgia Tech Research Corporation.