A serious defect has been discovered in the engine of the Lockheed Martin F-35A fighter jet, which is a top contender as Korea's next-generation fighter plane.
All test flights of the aircraft have been halted. If the defect proves a major problem, it will be back to square one for the Korean Air Force, which hoped to start buying 60 F-35As in 2016.
The U.S. Defense Department said a crack was discovered on the low-pressure turbine blades of the aircraft during an inspection at Edwards Air Force Base in California last Tuesday, news agencies reported on Friday. The crack was 1.5 cm wide.
As a result, the Defense Department decided to halt test flights of all version of the jet as a "precautionary measure" until the cause of the crack can be determined. The Pentagon added it is premature to speculate what impact the defect will have on the fighter plane.
The turbofan engine of the F-35A was developed jointly by Lockheed Martin and Pratt & Whitney and is used not only in the F-35A, but in the F-35B designed for the Marines and the F-35C for the Navy.
The discovery of cracks in the body of the F-35B late last year, as well as other smaller problems, have cast doubt on the reliability of the entire series.