Powering on

“It’s a very exciting time for the program right now,” said Bill Gostic, Pratt & Whitney’s vice president for the F135 program. “In addition to the CTOL flight testing that we have been doing we will begin shortly to engage in what we call powered lift flight test activity – we engage the STOVL lift components the lift fan, the three bearing swivel module along with the roll post.”

Of late, Gostic and the F135 team’s focus has been on an issue with the F135 for the STOVL F-35B variant of the JSF. Two third-stage turbine blades broke on a F135 during ground testing last year, causing Pratt to launch an intensive effort to investigate the causes of the failures and develop a remedy. This has delayed flight testing of the first F-35B by several months, but the JSF Program Office issued a ‘Statement of Qualification’ for F-35 STOVL full powered lift operations on January 31, clearing the engine for ground and pit testing, a critical milestone on the path to flight testing.

“We’ve studied that issue in great detail, determined the route cause, met with the government experts in the field of turbine engines, also brought in the best people we have from Pratt & Whitney and United Technologies, retired (engineers), people from academia,” explained Gostic of the resources and effort Pratt used to remedy the problems. “We developed a corrective action plan which we’ve no executed, and in fact have verified that we have reduced the stress on that third stage turbine blade to acceptable levels, and we completed the required testing to qualify not only the new turbine blade and vane but also to complete qualification of the STOVL propulsion system for both ‘up-and-away’ flight testing and powered lift flight testing.

That issues didn’t directly affect the CTOL version of the JSF Australia plans to acquire, but last year when the problems emerged some analysts had raised concerns that the cost and delays and resolving the problems could have undermined the case for STOVL variant of the JSF, which if cancelled would push up the unit price of conventional jets (the US Marine Corps wants 680 F-35Bs, the UK 150). Those concerns have abated now the statement of qualification has been issued – for the first time, Gostic noted, “for a propulsion system that could perform short takeoffs, vertical landings and fly supersonically.”

That is good news for a JSF program that as a whole has suffered some delays, but seemingly no critical issues, and with the program’s emphasis now beginning to move from development into production. On the engine side this means Pratt & Whitney has undertaken 11,000 of 14,000 ground test running hours with F135s, have tested 10 of 11 ground test engines, have built 11 of 18 flight test engines have now been built for flight test F-35s. Gostic says about 85 per cent of the engine’s development risk has now been retired.

“We really are progressing quite nicely here with our program,” says Gostic. “There’s many exciting things going on this year, ground testing, flight testing, and delivery of production engines.”

As development and testing is completed, production ramps up. In July this year Pratt & Whitney will deliver the first F135 production engine, one of four being built under LRIP (Low Rate Initial Production) contract Lot 1. A further 16 engines will be built under LRIP 2, with Gostic expecting up to 23 F135s to be procured under LRIP 3. By the second half of 2010 Gostic expects Pratt & Whitney to be building two F135s a month.

“We’re in the air and in production.”

And as production ramps up at Pratt & Whitney, so too do effort at it Pratt’s international suppliers. So far Pratt & Whitney has 44 international suppliers to the F135 program, including two from Australia, Production Parts and Levitt Engineering. Pratt & Whitney has long said it has selected its international partners on a “best value basis”, but taking on international partners and not keeping all work in house has certainly meant a cultural change for P&W.

“culture change quote”

Just how many engines Pratt & Whitney and its partners will build for the JSF program remains to be seen. Today stated requirements from the US and partner nations stand at around xxxx, but with the US budget racking up enormous deficits it remains to be seen how the new President Obama’s administration will fund the program. And there is the competitor General Electric/Rolls-Royce F136 engine. The F136 has survived a number of attempts by US Department of Defense to cancel the engine as a cost cutting measure, but the US Congress keeps reinstating development funding. The F136’s backers say the investment in developing a second engine will be more than recouped by competitive cost pressures between the two engines as they fight for future F-35 orders.

“Both engines are optimised for the JSF,” Gostic says of the F135’s advantages, “the difference is our engine is derived from (the F-22’s) F119 engine. The F119 has 100,000 hours of operational time, and we’ve learned many things from that engine that we’ve been able to incorporate into the F135.” Gostic argues that experience with the F119, and Pratt’s five year head-start in developing the F135 over the F136 “gives us a significant advantage in security.”

In the Australian context those competitive advantages may be a moot point. Production of the F136 is not due to begin until 2012 (flight testing won’t begin until 2010), with Australia due to begin taking deliveries of its first F-35s in 2013, perhaps too soon to be an F136 customer. But any delays to Australian procurement plans could bring the second engine into play.

“I learned a long time ago there’s really nothing I can do about GE, there’s nothing I can do about the political system here in the United States or for that matter in any of the partner countries,” Gostic notes.

With the first US F-35 training squadrons due to take delivery of their first F-35s in 2010, there’s certainly enough for JSF program leaders to concentrate on.