Aircraft

^{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 during a 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 P&W’s 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 Rolls-Royce Fighter Engine Team (FET) emphasises the failure occurred with prototype hardware, as opposed to the later build-standard of its competitor. FET 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.