Enemy forces might not defeat Australia's fleet of F-35A joint strike fighter jets – but corrosion could. An Australian television report revealed May 6 that the F35A jets are susceptible to intergranular corrosion, which can cause stress cracking and tensile stress. Intergranular corrosion results from a chemical reaction between the metal part and another substance or condition in the surrounding environment, such as salt, humidity, sea water and so forth.
The news surfaced when Australia's ABC-TV brought to public attention the controversy surrounding a 2017 report prepared by KPMG, an international consulting and auditing firm that had been contracted to investigate corrosion treatment options for the 72 F-35A jets that Australia's air force bought from U.S. manufacturer Lockheed Martin for $17 billion.
The report mentioned Aluminum Alloy 7085 as a probable cause for the corrosion problem. Prior to this, the alloy had not been used in any large-scale manufacturing of military aircraft. To address the issue, KPMG recommended full-time use of mobile dehumidification units, in conjunction with other measures. So far, the only jets affected by the problem were those located at the Williamtown Royal Australian Air Force base, near Newcastle.
Pentagon dispute with manufacturer over similar problem
Australia isn't the only country dealing with a corrosion issue in F-35A fighter jets. In a related development in April 2018, Reuters noted that the U.S. Department of Defense had stopped accepting deliveries of F-35A jets from Lockheed Martin because of a dispute over who was responsible for repairing a defect involving corrosion around fastener holes. Reuters' sources said that government inspection during manufacturing did not uncover the fastening issue, and Lockheed did not catch it either. Consequently, both the customer and the defense contractor have been wrangling over who will pay for the costly repairs.
Reuters reported that the problem was discovered during routine maintenance at Hill Air Force Base in Utah in 2017, when corrosion was found in the area where a carbon fiber exterior panel joined the aluminum airframe. The corrosion, judged to be higher than acceptable limits, was attributed to the lack of a protective coating where the materials were fastened, according to Reuters.
Worldwide impact of F-35A corrosion issue
According to Military.com, Lt. Gen. Arnold Bunch, the Air Force's military deputy for the Office of the Assistant Secretary for Acquisition at the Pentagon, who confirmed the suspension of F-35A deliveries in April 2018, the disruption was not expected to impact any major training or operational missions.
However, considering the Dallas Business Journal reported that the F-35A jets are also used by Japan, Italy and other international partners, the corrosion problem is something that Lockheed will have to handle on an international scale. As Reuters noted in its article, quoting anonymous sources that were not authorized to speak publicly, the solution will involve "a complex logistical fix that could require technicians to travel widely to mend aircraft based around the world." Reuters added that a ripple effect can happen when the U.S. halts production in this manner. Its sources said that at least two foreign nations have also stopped taking delivery of F-35As as a result.