Air Power to improve F-35A fuel tanks to climate lightning strikes

The F-35A Lightning II might begin flying close to thunderstorms once more quickly, as soon as the Air Power finishes upgrading its first jet for further safety towards lightning strikes.

If the upgrades go in line with plan, one F-35A — essentially the most extensively used Joint Strike Fighter variant — by July could be allowed to renew unrestricted flight for the primary time in nearly two years, Joint Program Workplace spokesperson Laura Seal informed Air Power Occasions.

The others will comply with go well with as they’re outfitted with new {hardware}, although Seal wouldn’t say what number of have to be modified. The Air Power owned about 300 F-35As as of fiscal 2021.

In spring 2020, officers banned the F-35A from flying inside 25 nautical miles of lightning or thunderstorms after discovering {that a} essential system might not operate accurately if hit by a bolt.

At problem is the Onboard Inert Gasoline Era System, or OBIGGS, which injects nitrogen-enriched air into the jet’s gasoline tanks. That makes the flammable tanks nonreactive so that they gained’t explode when struck by lightning.

However a staff making routine repairs to the superior stealth fighter discovered worrisome injury to the tubes that pump nitrogen into the tanks. Lockheed claimed the issue was occurring after the jets have been delivered to the Air Power.

Defective inert fuel tubes confirmed up in additional than half of the 24 airframes that have been inspected, Bloomberg reported on the time. That prompted an effort to revamp the OBIGGS system for the second time in 10 years.

“The basis trigger for the nitrogen tube failures remains to be below investigation. That stated, the F-35 Joint Program Workplace and Lockheed Martin labored aggressively to develop and deploy an engineering repair that eliminates the issue, at the same time as we proceed to analyze the foundation trigger of harm within the authentic OBIGGS configuration,” Seal stated.

The flight restriction will apply to a shrinking variety of planes because the army works by the fixes. Nonetheless, the ban is anticipated to final by the tip of 2025, or when all affected plane ought to be up to date.

Lockheed has put in an improved model of OBIGGS onto all F-35As delivered since November, Seal stated. For fighters which were in use longer, crews will add on the brand new {hardware} at their native models.

“A 2022 software program replace will warn the pilot each time the efficiency of OBIGGS is detected to be degraded,” Seal added.

The flight restriction hasn’t been foolproof, nonetheless.

Lightning struck an F-35A in midair Aug. 3, 2021, in a beforehand undisclosed incident, damaging the jet’s cover and physique panels, in line with an inventory of essentially the most extreme Air Power accidents in fiscal 2021. Air Power Occasions obtained the checklist Jan. 14.

Nobody was harm and the pilot returned to base with out problem. The jet belonged to the Air Power Warfare Heart’s sixth Weapons Squadron, a unit at Nellis Air Power Base in Nevada that provides postgraduate weapons and ways coaching for the F-35A.

The Air Power listed the strike as a Class B mishap — one which price between $600,000 and $2.5 million to restore, completely and partially disabled somebody, or despatched a minimum of three folks to inpatient hospitalization. Seal stated the incident remains to be below investigation and the ultimate restore price might change.

It got here a few week after lightning severely broken two Marine Corps F-35Bs to the tune of $570,000. No Marines have been injured. The Marines Corps initially estimated the restore price at greater than $2.5 million however later downgraded the mishap to the lower-cost Class C, Seal stated.

F-35 models throughout the Air Power, Navy and Marine Corps have reported being hit by lightning 15 occasions as of Jan. 25, or one damaging strike per 30,000 flight hours, Seal stated. Every incident has brought on between $25,000 and $570,000 in repairs.

“It’s unknown how usually F-35s are hit by lightning, because the fleet is simply required to report lightning strikes that end in reportable mishaps,” she stated. “All reported strikes occurred whereas in flight, with none affecting the pilot’s means to function the plane safely.”

No damaging strikes have been reported for Lightning II plane sitting on the bottom, the place they’re aided by gear like zap-proof plane shelters.

“We now have discovered an amazing deal about how lightning propagates by composite plane that will likely be used for designing future plane,” Seal stated. “The F-35 is extra resilient towards lightning strikes than initially anticipated, and we’ve got discovered that the superior avionics proceed to operate with out problem in all documented lightning strike occasions, validating the design requirements used for this gear.”

Simply because pilots might finally be cleared to strategy dangerous climate doesn’t imply they need to.

“Per U.S. Air Power flight laws, pilots of all USAF plane — not simply F-35s — are instructed to not deliberately fly right into a thunderstorm,” Seal stated.

Rachel Cohen joined Air Power Occasions as senior reporter in March 2021. Her work has appeared in Air Power Journal, Inside Protection, Inside Well being Coverage, the Frederick News-Publish (Md.), the Washington Publish, and others.