LOCKHEED MARTIN FIGHTER PROJECT NEAR FLIGHT TEST STAGE.

Byline: Jim Skeen Staff Writer

PALMDALE - Lockheed Martin is nearing first flight of its short-takeoff/vertical landing version of the joint strike fighter, the last configuration to be tested in the battle for the nation's richest military aircraft program.

Lockheed Martin's X-35B has begun ground runs at Air Force Plant 42 in Palmdale in preparation for its first flights. The first flights will be brief, consisting of a vertical takeoff, hovering and conducted flight control checks, and then setting back down, company spokesman John Kent said.

``We're getting pretty close,'' Kent said. ``The plane is ready to go. It's a matter of checking off boxes.''

First flight could occur as early as this month.

After the brief hover flights, the airplane will be flown to Edwards Air Force Base for the first half of the flight test program. The airplane will later be tested at the Navy's flight test center at the Naval Air Station at Patuxent River, Md.

The airplane's first pilot will be Simon Hargreaves, a veteran British Harrier jet pilot from BAE Systems, one of Lockheed Martin's major teammates on the program.

Lockheed Martin is competing with Boeing to build the multiservice joint strike fighter in what is being billed as a potential $750 billion to $1 trillion program.

The joint strike fighter is being developed to replace the Air Force's F-16s and A-10s and the Marine Corps' AV-8B Harrier and F-18 fighters. The fighter will also augment the U.S. Navy's F-18 fighters.

The United Kingdom is a partner in the program and wants the jets to replace its Sea Harrier and GR-7 jets. The British are investing more than $2.8 billion into the development of the joint strike fighters.

Combined, the two nations plan to buy more than 3,000 joint strike fighter aircraft. There is a potential for an equal number of sales to U.S. allies.

The ability of the aircraft to hover, then transition into normal flight, is one of the major tasks the contractors need to demonstrate to the United States armed forces and the United Kingdom's Royal Navy and Royal Air Force.

The meet those requirements, the two contractors are taking different approaches.

Boeing, whose short takeoff/vertical landing X-32B is already being tested at Patuxent River, is going with improved variations of the direct-lift systems already used by Harrier jets. To take off and land vertically, the engine system redirects engine thrust downward through lift nozzles. To transition back to normal flight, the nozzles are closed and the thrust directed to the rear.

Boeing officials say there is 30 years' experience in working with such engine systems and that it is the only combat-proved STOVL technology.

Lockheed Martin is trying a new system that uses a shaft-driven lift fan mounted directly behind the cockpit to generate cool-air vertical thrust. Lockheed Martin officials say the system generates more lift and, because it runs cooler, helps the engine run more efficiently.

Lockheed Martin mounted the lift fan to the aircraft that had already flown as the conventional X-35A, testing its suitability for Air Force use.

Both contractors are required to submit all of their flight test information by Aug. 15. The Pentagon is expected to make a decision later this year as to which company will build the jets.