Both bids surpassed requirements, but Lockheed Martin excelled in more areas

Boeing's decision to use a direct-lift, short take-off and vertical landing (STOVL) propulsion system was the main weakness in its unsuccessful Joint Strike Fighter (JSF) bid, says the head of the company's military aircraft business. In contrast, Lockheed Martin's successful demonstration of a shaft-driven lift fan in its STOVLJSF "opened the door to a performance improvement Boeing could not get", says Military Aircraft & Missiles Systems chief executive Jerry Daniels.

After being debriefed on the US Department of Defense's evaluation of its unsuccessful proposal, Daniels says: "Boeing's Grade A effort was beaten by Lockheed Martin's Grade A-plus. Both designs met or exceeded the requirements, but Lockheed Martin exceeded in more areas, and in some very key areas." He says Boeing "sees no reason to challenge the Government's findings".

Lockheed Martin says it has been asked by the DoD not to release details of its debrief, but "it was clear that the Lockheed Martin team solution was evaluated across the board as the best choice" ,says Aeronautics sector president Dain Hancock. The Lockheed Martin/Northrop Grumman/BAE Systems team has received a $18.9 billion contract for JSF system development and demonstration.

Daniels says that, while Boeing scored higher on overall management and past performance and the companies tied on cost and affordability, Lockheed Martin "scored consistently higher on air vehicle design. In most areas they had the edge." Boeing's design was also considered to be higher risk. "Lockheed Martin had an aircraft design that gave the government clear advantages over Boeing's, which Boeing's advantages in management and past performance were not enough to overcome," he says.

Although the STOVL variant accounts only for 20-25% of the planned 3,000-aircraft production run, observers had long expected the JSF decision to revolve around the different vertical lift concepts. When Boeing and Lockheed Martin were awarded concept demonstration contracts in 1996, the DoD rejected the lift-plus-lift/cruise concept proposed by McDonnell Douglas (MDC). Losing the JSF competition precipitated MDC's merger with Boeing, the company forming the core of its Military Aircraft & Missile Systems sector.

"In 1996, the DoD selected Boeing's design because it was innovative, with high potential but also high risk," says Daniels. The company had chosen direct lift because of its simplicity, proven operational success on the Harrier family developed by BAE and Boeing (formerly MDC) and because it allowed high commonality between the three JSF variants. But "direct lift did become a weakness", he says. As the JSF requirements evolved, "compromises were made in the design [resulting in] thin margins on certain parameters". Aircraft weight was an issue with direct lift "and the propulsion concept required us to run the engine in high-temperature modes, leading to engine life risk", he says.

Lockheed Martin selected an innovative shaft-driven lift fan propulsion system because it provided 60% more vertical thrust than the unaided engine, but from the outset the concept was considered high risk because of its complexity. The two-stage fan is driven by the engine via a shaft, clutch and gearbox. "The question was will it work reliably?" says Daniels. "Lockheed Martin demonstrated its reliability to the satisfaction of the Government, opening the door to real strengths in other areas."

While Lockheed Martin took a risk in basing its STOVL JSF around a lift fan, Daniels says Boeing took one in using direct lift to produce three "very common variants" of its design. "We got as much performance out of it as possible, but could not provide the performance margin." He says Boeing was aware of the weaknesses of its lift system at the JSF proposal phase. "We needed to see Lockheed Martin's lift fan not perform for us to win."

In the other two variants - the USAir Force conventional take-off and landing (CTOL) and US Navy aircraft carrier (CV) aircraft - the two JSF proposals "measured up quite well", says Daniels. "Both were good aircraft that exceeded the requirements, but Lockheed Martin had more strengths than we did." Boeing's design had good up-and-away performance, he says, adding: "We had a red-hot aircraft that flew well."

Source: Flight International