Issue 290: On Target?

At least flight test in 2011 proceeded relatively smoothly (an issue with the integrated power pack aside which led to a short grounding of the fleet).

“We’re about 10 per cent, maybe a little better, ahead on the flight test program at the moment, both in terms of flights and test points,” Burbage noted.

Highlights for 2011 have included the F-35A demonstrating its Mach 1. 6 maxi-mum speed and full 9g manoeuvring limit, two F-35Bs successfully completed initial at sea trials operating from the LHD USS Wasp, the F-35C successfully completed test catapult launches, and the rollout of the first international F-35, an F-35B test aircraft for the UK.

Other milestones were imminent – the USAF was due to begin flight operations with its initial six F-35As at Eglin Air Force Base in Florida, and the Block 2A software standard was due to enter flight test on the F-35 (rather than the CATbird 737 testbed) either in late December or early January, only a little behind schedule.

As at November 30, 22 SDD and LRIP F-35s had flown, and to that date in 2011 the 13 flying F-35As had flown 440 times, the eight STOVL F-35Bs 308 times and the three carrier variant F-35Cs 154 times.

But much flight testing remains. “Over-all, from a flight test perspective, we’re about 20 per cent complete to the plan,” said Burbage. And while many of the test points yet to be ticked off relate to weapons testing, the F-35 is still to fly at night (ex-pected in 2012), fly from an aircraft carrier (planned for 2013), or release weapons, so key flight test milestones remain.

Also remaining is much of the fatigue testing of the aircraft, and it is here that bigger problems loom around the issue of ‘concurrency’ – where production is underway even though testing is revealing the need for modifications to the design to meet its planned 8000 hour fatigue life.

Burbage says the F-35 is 20 per cent through its fatigue lifetime testing. “But as you discover parts of the airplane that don’t have a full 8000 hour life, you have to decide whether you’re going to change that part now, or change it later or change it at all. ” Indeed, the number of potential cracks and hot spots discovered in the F-35’s airframe during fatigue testing has led the head of the US Joint Program Office to call for a slowdown of production over the next few years.

US Navy Vice Admiral David Venlet said in an interview with AOL Defense in November that fatigue testing had already found enough parts that require redesign or replacement to add roughly US$3 to $5 million to the cost of each jet that will require a retrofit.

Venlet said the problems would not affect safety or performance of the fighter, but would shorten its lifespan and were best addressed now.

“Most of [the problems] are little ones, but when you bundle them all up and package them and look at where they are in the airplane and how hard they are to get at after you buy the jet, the cost burden of that is what sucks the wind out of your lungs,” Venlet said. “I believe it’s wise to sort of temper production for a while here until we get some of these heavy years of learning under our belt and get that man-aged right. ” Venlet also criticised as a “miscalculation” the program’s assumption that F-35 pro-duction could begin even as flight testing continued, though he said it remained his job to see the program through as it was.

Concurrency was also highlighted as an issue by a ‘Quick Look Review’ panel which prepared a report into the health of the program for acting Pentagon acquisi-tion chief Frank Kendall. That review found that there were five “major” design issues with the jet (the latency issue with the helmet mounted sight, the fuel dump system, the hook on the F-35C, the IPP and a “classified issue”), but “identified no fundamental design risks sufficient to preclude further production. ” “The F-35 is early in its flight test execu-tion. The program has been finding, and expects to continue to find, issues which will required consideration of potentially significant rework to concurrently procured aircraft,” the QLR report, dated November 29, reads. “The most challenging portions of flight test (high angle of attack flight, missions systems and weapons employ-ment) have yet to be entered and the team anticipates that these stressing cases will produce additional discovery of issues with potentially significant design impact. As a result, the QLR team assesses the current confidence in the design maturity of the F-35 to be lower than one would expect given the quantity of LRIP aircraft procurements planned and the potential cost of reworking these aircraft as new test discoveries are made. The QLR team recommends that further decisions about F-35 production be event driven, based on achievement of sufficient test data to support increased confidence in design ma-turity and of a well controlled process for executing and minimising design changes across concurrent production. ” As it happens, under current planning F-35 production will slow down some-what before ramping up again. Lockheed Martin is building 32 F-35s under LRIP 4 (low rate initial production batch 4) but only 30 (instead of 120 as once mooted) are planned to be built under LRIP 5. Lockheed Martin and the Pentagon finally agreed to the contractual terms of LRIP 5 in December, many months behind schedule, after wrangling over concurrency costs, which was a key factor in the reduced buy number.

On current planning LRIP 6, which will include the first two Australian F-35As, would see 48 F-35s funded, with progres-sively more in LRIPs 7 through 11, before F-35s are acquired under multiyear buys, planned from 2017.

But it remains to be seen what numbers are funded in subsequent US defence budg-ets (assuming that the threat of ‘sequestra-tion’ – an arbitrary US$1 trillion cut to the US defence budget over a decade that would kick in if the US Congress cannot agree to budget cuts – doesn’t come to pass) as the concurrency debate plays out.

“So far we’ve had one failure, and that was the bulkhead on the STOVL airplane, the rest of our limited life parts are by analysis, . . . we’re predicting looking forward what parts will have less than the full life of 8000 hours,” said Burbage. “Some of the things are structural, some of the things are components. The structural changes tend to be more invasive, they take more time to do so they become the more expensive piece. ” Burbage also noted that modelling is far more comprehensive for F-35 fatigue life compared to what was done for legacy jets.

“In our case we’re predicting all those [fatigue issues] right now, we’re telling you this is what we think it is going to be, and you need to figure out how fast can we get those [fixes] in the airplane and how much is it going to cost. That’s where the controversy is. ” Over the longer term though, Lockheed Martin still maintains that the “estimated average unit recurring flyaway cost” of an F-35A is US$65 million (in 2010 dollars). But that is the average cost over the life of a planned 3000+ unit production run. Early production aircraft will cost more until the production rate ramps up and achieves economies of scale.

“The good news is nobody, including the United States, has reduced their [buy] number. Almost everybody has reduced the rate at which they’re starting up their ramp. The question remains whether there will be reductions in the future, but as of right now there haven’t been any. ” As for Australia, Burbage characterises Australia’s commitment to the F-35 as “pretty solid”. He also noted that Lockheed Martin had been given an informal verbal debrief by Defence’s SCRAM (Schedule Compliance Risk Assessment Method) team, which had visited Fort Worth in October as part of the review into the F-35 program being undertaken for Defence Minister Stephen Smith.

“Their assessment in their verbal debrief to us is that they thought we’re making good progress,” Burbage related.

Meanwhile, in other F-35 news General Electric and Rolls-Royce have officially dropped development of the F136 “alter-nate” engine for the JSF. The US cut fund-ing for the program in February. GE and Rolls-Royce had said they would self-fund continued development, but announced an end to the program on December 1. n