DARPA’s Liberty Lifter programme is about designing, building, and testing a seaplane that can operate efficiently at less than 100 feet (30 meters) above the ground, hold flight altitudes of up to 10,000 feet mean sea level and transport massive payloads at speeds faster than current sea lift platforms while shifting the paradigm of strategic lift to a cost per ton instead of cost per pound approach.The planned Liberty Lifter demonstrator will be a large flying boat with the same size and capacity as the C-17 Globemaster III transport plane. Take-off and landing in Sea State 4, sustained on-water operation up to Sea State 5, and extended ground effect flight close to the water with the capability of flying out of ground effect at altitudes up to 10,000 feet above sea level are all goals.DARPA Liberty Lifter Programme Manager Christopher Kent said, “the two teams have taken distinctly different design approaches that will enable us to explore a relatively large design space during Phase 1.”(Photo Darpa)The General Atomics team chose a twin-hull, mid-wing design to optimise on-water stability and seakeeping. It uses twelve turboshaft engines for distributed propulsion. (Photo Darpa)Aurora Flight Sciences’ point-of-departure design is akin to a traditional flying boat, with a single hull, high wing, and eight turboprop engines for primary propulsion.During Phase 1, DARPA will collaborate with performer teams and Department of Defence stakeholders to fine-tune the Liberty Lifter designs, paying particular attention to operational requirements and operating concepts. The Phase 1 contract awards are for an 18-month performance period, which includes six months of conceptual design work and nine months of design maturation culminating in a preliminary design review. Manufacturing planning and test/demonstration planning reviews will take an additional three months.Phase 1 will conclude in mid-2024 with continued detailed design, manufacturing, and demonstration of a full-scale Liberty Lifter X-Plane. DARPA expects to collaborate with one or more DoD Services and international partners on these activities and further develop the Liberty Lifter concept into an operational vehicle.General Atomics was awarded an $8 million cost-plus-fixed-fee contract in November to support DARPA's Liberty Lifter programme, the company announced Wednesday. The contract may include options worth up to $29 million. Aurora's contract, which DARPA awarded on January 27, was worth $5.7 million but could be worth more than $25 million if all options are exercised. On January 27, Aurora, a Boeing subsidiary, was awarded $5.7 million with opportunities to increase the contract to $27 million.