The F-35 Lightning II strike fighter has previously undisclosed problems with its handling, avionics, afterburner and helmet-mounted display, according to a report by the Pentagon?s Director of Operational Test and Evaluation.
The United States is covering 90 percent of the cost of the development but
has participation from Britain, Italy, Turkey, the Netherlands, Canada,
Denmark, Norway and Australia.
The F-35 fighter aircraft is seen at Lockheed Martin's production plant in Fort Worth, Texas August 31, 2009.
Credit: Reuters/Jessica Rinaldi
Senior Air Force leaders are growing increasingly concerned that Joint Strike Fighter maintenance and operating costs will rise far above previous estimates.
A source familiar with the issue said that the Air Force believes a study performed by the Navy one year ago looks increasingly accurate, based on preliminary data the service has compiled. Buzz readers will remember that the Navy study found the F-35 would cost between 30 percent and 40 percent more per plane than does the current F/A-18 fleet. Since one of the primary goals of the F-35 program, with its web of international partners, was to lower maintenance costs by achieving economies of scale through large program buys by a significant number of countries this would call into question one of the fundamental goals of the program. Another key to achieving those savings was an international PBL contract (Performance Based Logistics). It would spread work share throughout the JSF allies and guarantee greater economies of scale than the U.S. could achieve on its own.
JPO on STOVL F-35 Design Issues
The Joint Strike Fighter program office has provided the detail behind defense secretary Robert Gates' Jan. 6 comment that issues with the STOVL F-35 "may lead to a redesign of the aircraft's structure and propulsion". (You can read AMy Butler's story here.)
There are no surprises on the list. The issues detailed by the JPO have been reported on before, and in most cases fixes are in design or in test. They are: lift-fan clutch heating, driveshaft thermal expansion, roll-post heating, lift-fan doors, bulkhead cracking and pilot-vehicle interface issues.
Full article at AW&ST
Lift-system prime contractor Pratt & Whitney says the lift-fan clutch and roll-post actuators can get too warm in certain flight conditions "because the environment surrounding the hardware is more demanding than in the original design". Sensors are being installed to monitor temperatures.
Branyan says the problem is heating of the roll-post actuator caused by leakage of hot engine air as the roll nozzle seals age. Insulation is being added. For now, the amount of time the aircraft spends in STOVL Mode 4 (jetborne flight) is being limited.
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