AMC-X - Advanced Mobility Concept Aircraft

In order to meet the tactical requirements of tomorrow's force, work is continuing on the development of a short-take-off-and landing (STOL)/SSTOL aircraft as a replacement for the C-130. Such an aircraft is required in the long term both to replace the C-130 in its current role and mission and to support operations from a sea base. The Air Force has initiated the AMC-X program, leading to the development of the joint operational concept and requirement for future tactical airlift capabilities to support joint land force, maritime, and air operations as well as other theater airlift needs. The needs identified by the Army present a formidable technical challenge: a craft with an 80,000-pound payload, to accommodate two Stryker or Future Combat System vehicles, and a SSTOL landing profile. Yet achieving that capability would also go far toward meeting a high capacity seabasing connector requirement.

Among the contributions to the Air Force AMC-X and M-X studies are proposals for a C-130J successor, which, with a fuel-pluspayload takeoff weight of 72,000 pounds and a 10-knot headwind, can achieve takeoff with a ground roll of 992 feet. These performance characteristics would begin to make this concept compatible with shipboard operation (at least for a carrier without an island or bridge). The studies claim that the proposed aircraft can achieve takeoff with a ground roll of 635 feet with a fuel-plus-payload takeoff weight of 72,000 pounds, if the ship's speed generates a wind of 35 knots over the deck. They also claim that, if the proposed aircraft were to take off with the same payload and only half of the fuel load (and retank after takeoff), it could achieve takeoff with a ground roll of only 441 feet. The availability of an electro-magnetic [EM] catapult would reduce takeoff roll even further.

The availability of such a SSTOL aircraft with the attributes described in Air Force studies would have a major impact on the mobility of U.S. forces and on the value of the sea-base concept. Aircraft that could land and take off from a realizable ship with payloads of 46,000 pounds would allow the movement of a Stryker vehicle or International Standards Organization (ISO) containers to and from a sea base by air. Although it is likely that only one aircraft could be accommodated at a time, they would mitigate many of the problems associated with the transfer of such equipment with surface connectors.

The development of a SSTOL replacement for the C-130 would contribute significantly to force mobility. The achievement of a SSTOL capability would be especially important if the design of future sea-base platforms incorporated flight decks long enough and wide enough to accommodate the takeoff and landing of SSTOL aircraft with loads in the 40- to 50-thousand-pound range. There has to be close coordination of the Navy's sea-base activities and the Air Force AMC-X and MC-X to achieve mutual compatibility of the SSTOL and the sea base.

Unlike the sealift situation, the needs for a possible aircraft to succeed the venerable C-130 differ from the strategic airlifter requirements and entail demanding technology advances. The design of airplanes to exploit "austere" airports has been a technological focus for some forty years. One concept, named AMC-X, could represent an especially significant development, particularly if it should prove capable of operating not only from land bases, but also from the deck of carrier-size vessels in a sea base. A heavy-lift capability of that sort-something available only from a fixed-wing aircraft-could be useful not just for mobility, but also for surveillance, radio relay, and ground fire support.