The Pentagon has issued a restriction order for Lot 9 and newer Lockheed Martin F-35A Joint Strike Fighters after the discovery of cracks in the aircraft’s stealth coating following the use of the 25mm gun.
Concerns over the F-35 have been the focus point of the Director, Operational Test and Evaluation: FY2019 Annual Report conducted by Robert Behler, Director of Operational Test and Evaluation (DOT&E) within the Office of the US Secretary of Defense.
Behler’s report said the program was working to fix deficiencies however new discoveries are still being made which resulted in only a minor decrease in the overall number of issues.
“There are many significant deficiencies that should be addressed to ensure the System Development and Demonstration (SDD) baseline configuration is stable prior to introducing the large number of new capabilities planned in Block 4,” the report said.
One of the most startling revelations in the report was that airframes of the Lot 9 build, and subsequent lot builds, have experienced cracks in the outer mold-line coatings and the underlying chine longeron skin, located near the 25mm gun muzzle of the F-35A variant.
While all three variants of the F-35 share a 25mm gun, the F-35A has an internal gun system.
The short take-off and vertical landing (STOVL) F-35B, and the aircraft carrier-specific F-35C variant, mount the 25mm gun in an external gun pod.
The Lockheed Martin F-35 Joint Strike Fighter is billed as a catalyst for the fifth-generation revolution.
Ten nations are currently flying F-35s, including the US, UK, Italy, Norway, Israel, Australia and Japan.
More than 340 F-35s are operating today with partner nations, more than 700 pilots and 6,500 maintainers have been trained, and the F-35 fleet has surpassed more than 170,000 cumulative flight hours.