The Lockheed Martin F-35 Joint Strike Fighter (JSF) programme systems development and demonstration budget is being targeted for cuts, which may result in a two-year slippage to the alternate engine being jointly produced by General Electric and Rolls-Royce.

The slippage, from 2011 to 2013, will coincide with the planned delivery timescale for the first short take-off and vertical landing aircraft for the UK. Although no firm decisions have yet been made, observers say the UK was a likely launch customer for the alternate F136 engine as R-R has a 40% share of the work versus a smaller percentage for the Pratt & Whitney-led F135 powerplant.

The JSF programme office confirms that a $511 million "inflation cut" will be made over five years from fiscal year 2004 to 2009. "The primary objective is to keep the first flight intact, and to do that we have to keep Lockheed Martin and P&W funded. So then the truly difficult decision has been made to slow down the GE alternate engine work," it says. Testing of the first full P&W F135 engine is due to start in the third quarter, and first flight of the initial production F-35 is expected in 2005.

GE says to date the F136 programme has "not been hit, and we are on the current schedule". However, it adds that should the cuts become unavoidable it will focus on ways of "preserving the engineering teams in the long term, and will continue to discuss options with the US government and the international partners". One possible option is believed to include refocusing the F136 effort on the conventional take-off and landing version, a solution seen by many as an obvious choice for GE, but clearly not for R-R.

Although the engine-maker team is discussing options, the JSF programme office sees little choice than to cut back the F136 effort. "Over time, GE is continuing work on the alternate engine. We just had to slow the pace to keep the first flight on track," it adds. Under the original timescale, the first F136 engines were to be delivered in 2010 for production lot number four, and the first full F136 engine test is scheduled for mid-2004.

Source: Flight International