By Guy Norris in Los Angeles
The General Electric Rolls-Royce F136 alternate engine for the Lockheed Martin F-35 Joint Strike Fighter (JSF) suffered a stall during GE-sponsored testing in Ohio in April, it has been revealed.
The news comes amidst the continuing debate in US government circles over whether to continue support for an alternative to Pratt & Whitney’s primary JSF engine, and just a week after news emerged of a temperature margin problem on its F135 (Flight International, 30 May - 5 June).
GE says the stall occurred during tests on the third pre-SDD (system development and demonstration) prototype engine, which had amassed around 30h since first running in February. Although details are scarce due to F-35 joint programme office restrictions, GE says the problem was “caused by an oil leak aft of the compressor, which led to an imbalance and a stall”. The engine, which had previously reached a maximum thrust in excess of 40,000lb (178kN), was immediately shut down and inspection later revealed rubbing damage to “some tips on the compressor blades.”
The GE R-R Fighter Engine Team (FET) emphasises the failure occurred with prototype hardware, as opposed to the much later build standard of its competitor. Unabashed by the problem, it plans to “begin the process of reconfiguring the pre-SDD engine later this year”, during which SDD-standard hardware including low pressure turbine blades, combustor and fan will be added. Engine No. 3, which was being used to help develop control system data when the stall occurred, will run again by the end of the year, while engine No. 2 will run with the new components early in 2007.
Ironically, the FET believes news of the problem will help, rather than hinder, its effort to maintain funding for F136. GE says it strengthens the case “that this is a complicated business”, and that both its own stall in testing, and the F135’s temperature issues, point to the continued need for dual sources of JSF engines.
Assuming the F136 programme continues to be funded the first full-up SDD engine is scheduled to run in mid to late 2008, with six flight test engines and a single spare due to be built.
The General Electric Rolls-Royce F136 alternate engine for the Lockheed Martin F-35 Joint Strike Fighter (JSF) suffered a stall during GE-sponsored testing in Ohio in April, it has been revealed.
The news comes amidst the continuing debate in US government circles over whether to continue support for an alternative to Pratt & Whitney’s primary JSF engine, and just a week after news emerged of a temperature margin problem on its F135 (Flight International, 30 May - 5 June).
GE says the stall occurred during tests on the third pre-SDD (system development and demonstration) prototype engine, which had amassed around 30h since first running in February. Although details are scarce due to F-35 joint programme office restrictions, GE says the problem was “caused by an oil leak aft of the compressor, which led to an imbalance and a stall”. The engine, which had previously reached a maximum thrust in excess of 40,000lb (178kN), was immediately shut down and inspection later revealed rubbing damage to “some tips on the compressor blades.”
The GE R-R Fighter Engine Team (FET) emphasises the failure occurred with prototype hardware, as opposed to the much later build standard of its competitor. Unabashed by the problem, it plans to “begin the process of reconfiguring the pre-SDD engine later this year”, during which SDD-standard hardware including low pressure turbine blades, combustor and fan will be added. Engine No. 3, which was being used to help develop control system data when the stall occurred, will run again by the end of the year, while engine No. 2 will run with the new components early in 2007.
Ironically, the FET believes news of the problem will help, rather than hinder, its effort to maintain funding for F136. GE says it strengthens the case “that this is a complicated business”, and that both its own stall in testing, and the F135’s temperature issues, point to the continued need for dual sources of JSF engines.
Assuming the F136 programme continues to be funded the first full-up SDD engine is scheduled to run in mid to late 2008, with six flight test engines and a single spare due to be built.
Source: Flight International
