Critical repair could allow Air Force F-35s to fly near thunderstorms

The Air Force says the F-35A Lightning II may soon be able to operate near thunderstorms or lightning again thanks to an upgrade to the aircraft’s fuel system. Once all jets have been repaired, the service’s F-35As could resume flying unrestricted in these weather conditions for the first time in nearly two years.

The fix affects the F-35’s Onboard Inert Gas Generation System, or OBIGGS. This system is designed to inject nitrogen-enriched air into the F-35’s fuel system to reduce the potential buildup of highly flammable vapors. If the interior of the aircraft’s main fuel tank and associated fuel lines are not kept “inert” by the OBIGGS system, a lightning strike can ignite these flammable gases and potentially cause an explosion.

Air Force Time
reported Today, F-35 Joint Program Office spokeswoman Laura Seal said the first F-35A to receive the repair could have it by July. Lockheed Martin has been installing an updated version of OBIGGS on F-35As since November 2020, but crews will need to install the new system on older planes that have already been delivered. It is unknown if the other variants currently in production have received the updated OBIGGS.

The F-35B and F-35C will follow after, Seal said, though she declined to comment on the number of planes needing the fix. In 2020, the Joint Program Office restricted the F-35 to fly within 25 nautical miles of thunderstorms or lightning. This restriction is expected to remain in place until all affected aircraft can receive the fuel system fix, which will hopefully be before the end of 2025. Seal says a software update coming this year will alert pilots whenever OBIGG system performance drops. detected.

“The root cause of the nitrogen tube failures is still under investigation,” Seal said. Recount
Air Force Time. “That said, the F-35 Joint Program Office and Lockheed Martin have worked aggressively to develop and deploy an engineering fix that eliminates the issue, even as we continue to investigate the root cause of the damage in the OBIGGS configuration of ‘origin.”

In 2020, Bloomberg
reported that problems with OBIGGS caused delays that resulted in a pause in the delivery of new aircraft while Lockheed Martin investigated the issue on the production line. However, it was later found that the problem was occurring in the field after the aircraft was delivered, prompting the F-35 Joint Program Office to issue a lightning-related flight restriction.

The Air Force F-35A variant was not the only variant to experience these problems. As early as 2015, the Office of the Director of Operational Test and Evaluation warned that OBIGGS was not keeping the F-35B fuel system sufficiently inert, stating that “if the residual inerting cannot be improved, the Aircraft maintainers will be required to drain fuel tanks. with external nitrogen more frequently or alternative lightning protection strategies (e.g. lightning protected shelters), will need to be adopted.

In addition to OBIGGS performance issues, another factor is that the F-35’s outer skin is covered with a composite metal structure that “does not provide inherent passive lightning protection,” according to a Marine Corps request. for portable lightning rods. This inherent lack of protection means that F-35s must be accompanied by lightning rods when stationed outdoors at bases that lack the infrastructure to protect them. It is unknown if the new OBIGGS patch will remove the need for lightning rods.

“It is not known how often F-35s are struck by lightning, as the fleet is only required to report lightning strikes that result in reportable accidents,” the Joint Program Office spokesperson said. . noted. “All of the reported strikes occurred in flight, with none affecting the pilot’s ability to fly the aircraft safely.”

Air Force Time reports that a previously undisclosed lightning strike occurred in August 2021 when an F-35A was knocked in the air. The jet’s canopy and body panels suffered damage requiring between $600,000 and $2.5 million to repair. The incident is still under investigation. Air Force, Navy, and Marine Corps F-35 units reported 15 strikes as of Jan. 25, each costing between $25,000 and $570,000 to repair.

Lightning protection is just one more hurdle to overcome for the jet, which has already seen its share of criticism for its high operating costs. The F-35 is the most expensive program in Pentagon history, expected to cost over $1 trillion to operate until 2070. It is unclear who pays for the cost of repairing the OBIGGS, but it is one of many modifications needed for the F-35 fleet – the older the aircraft , the more extreme the tweaks and upgrades. in them. In fact, many may simply retire as they will never reach their full lifespan or combat potential. However, it’s still good news that some of those residual technical issues that plagued the F-35 are finally being resolved.

Despite the price, if the OBIGGS repair rollout goes as planned this summer, Lightings will hopefully be able to fly near its atmospheric namesake again.

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Robert M. Larson