F-35C Grounded F-35 fighter fleet would soon resume flights, following the decision of the Pentagon to end the precautionary grounding...
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| F-35C |
According to Matthew Bates, a spokesman for Pratt & Whitney, initial examination has determined that the crack resulted from stressful operating environment experienced in flight tests – many of which tested the engine’s powerful afterburners – rather than a high-cycle fatigue crack, which would have required a design change. Inspections of other F-35 fighter jets did not find similar cracks or signs of excessive engine stress, therefore, no redesign will be needed for the JSF F-135 engines.
As a precautionary measure engine inspections will now be required every 25 flight hours, compared to usual 50 hours, Reuters reported
Cracked engine had operated at high temperatures for more than four times longer than a typical F-35 flight, which led to a separation of the grain boundary of the particular blade that experienced the crack.
According to the US Navy investigation, that engine had experienced the most “hot engine time exposure” of all the engines in the developmental program.
On February 19 Air Force technicians detected a 0.6-inch long crack in one of the turbine blades when performing a routine periodical inspection of the F-135 engine on AF-2 test aircraft operating at Edwards Air Force Base in California.
The finding triggered the week long flight suspension that began three days later. The affected turbine module and its associated hardware were sent to Pratt & Whitney’s Engine Facility in Middletown, Conn., to evaluate the root cause of the malfunction.
