JSF on Display at Farnborough

On show here in the form of a full-scale mockup, Lockheed Martin's Joint Strike Fighter design is being refined in readiness for the winner-take-all competition that -- according to Pentagon plans- should end within the year with a historic down-select decision.
The mockup here is in the conventional take-off and landing (CTOL) configuration. Almost two-thirds of the 3,000 JSFs that the U.S. plans to buy will be CTOL aircraft, as would most export JSFs.

The first X-35 concept demonstration aircraft (CDA), now being prepared for its first flight at Palmdale, will initially be tested in CTOL form as the X-35. After basic handling and flight qualities tests, it will be fitted with the shaft-driven lift fan, lateral roll nozzles and vectoring main exhaust of the Lockheed short take-off, vertical landing (STOVL) concept and tested as the X-35B.

The second demonstrator, the X-35C, represents the carrier-based (CV) variant of the fighter, with a larger wing and tail. The X-35C completed structural loads testing at the end of June. Its main task will be to perform simulated carrier approaches at the U.S. Navy's Patuxent River test base, to demonstrate that the design will be carrier-compatible.

The STOVL tests are the crucial part of the CDA program. At the same time as the Pentagon said the JSF program would be winner-take-all, Pentagon acquisition chief Dr Jacques Gansler disclosed that neither team expects to demonstrate STOVL-a short take-off followed by a deceleration to hover and touch-down at a realistic mass-before March or April. The original schedule called for STOVL tests this winter, but the latest JSF plan can accommodate a slip of STOVL tests into the summer.

Comments from Gansler and Defense Secretary William Cohen reflect some anxiety that one or both of the teams may not achieve a full STOVL transition. One team, Gansler remarked at a June media briefing "could self-eliminate if they don't fly. But as we now expect, they will both fly."

Lockheed Martin has encountered some problems with overheating bearings in the clutch mechanism that drives the lift fan. The lightweight mechanical transmission delivers 20 megawatts of power from the engine to the fan-in the same order as the propeller shaft of an Aegis cruiser. Another key, untested feature of the concept is the use of fore-and-aft and left-to-right thrust switching, rather than dedicated reaction nozzles, for control in jet-borne flight.

Meanwhile, Lockheed Martin has unveiled a high-fidelity sensor integration facility to support development of the JSF's avionics system. Located at Fort Worth, Texas, the facility includes a full-size JSF model, mounted on a 40-foot tower, which can be equipped with realistic sensor apertures linked to Lockheed Martin's commercial off-the-shelf (COTS) mission computer and a manned simulator cockpit.

A new member of the Lockheed Martin JSF team is the Strategic Alliance, a long-term joint venture formed by Honeywell International and Cat Logistics, a wholly owned subsidiary of Caterpillar. The Alliance will assist Lockheed Martin with supply-chain management and product support.

By Bill Sweetman