JSF requirement cap likely as rising costs force choices

Graham Warwick/WASHINGTON DC

The US Department of Defense (DoD) is likely to modify critical elements of the Joint Strike Fighter (JSF) in an attempt to cap escalating costs.

Industry believes that the next iteration of the JSF requirements document will incorporate changes intended to reduce the costs of the three planned variants. Changes could include reduction of internal weapons carriage requirements from two 900kg weapons to two 450kg munitions, to allow a smaller, common, weapons bay.

Commenting on reports that escalating requirements are pushing up the price, Boeing's JSF programme manager Frank Statkus says changes are being made to the joint requirements document "-to keep weight and cost down."

The JSF requirements are still evolving as Boeing and Lockheed Martin work on their concept demonstrations and development proposals. A draft of the third requirements iteration is expected in July, and will be the last before the final joint operational requirements document is released.

Statkus admits that Boeing's JSF design is now exceeding the cost targets. The unit flyaway cost of its conventional take-off and landing (CTOL) variant for the US Air Force is "a little higher" than the target of $28 million, he says.

Statkus expects affordability initiatives, including further work on the inlet, weapons bays and landing gear, "-to bring down cost significantly. We are driving for the CTOL cost to be much lower than $28 million because we expect cost growth in development".

Lockheed Martin declines to comment on the cost of its JSF design, but deputy programme manager Harry Blot says the company is pressing the Government to change its cost estimating procedures to give credit for manufacturing improvements that are part of its proposal. "Classic cost models based on history don't work with this programme. The problem is proving it," he says.

Boeing reveals that commonality between its three JSF variants - USAFCTOL, US Navy carrier-based (CV) and US Marine Corps/Royal Navy short take-off and vertical landing (STOVL) - has reduced as the design has evolved. Originally around 85%, commonality is now "in the high 70s", Statkus says.

"We thought that maximum commonality would drive the unit cost down, but we overshot and compromised the configuration," he says, adding: "Now we hold commonality to the point where it compromises one of the aircraft, until it becomes a cost driver for one version." The CV mission was driving structural weight, "-so we backed off [on commonality] to give a lower weight for STOVL and lower cost for CTOL," he says.

Source: Flight International