HILL AIR FORCE BASE — Ongoing F-35 testing has revealed the jet’s ejection seat could cause fatal neck injuries to lighter-weight pilots.

But officials from both Hill Air Force Base and the Pentagon say that while safety is their No. 1 concern, the issue will have little to no impact on current flying operations.

According to the Pentagon’s F-35 Joint Program Office, all U.S. services are prohibiting pilots who weigh less than 136 pounds from flying the jet. The restriction was put in place in late August, after testing uncovered an increased risk of injury that could occur during a low-speed ejection.

A Defense News report Oct. 5 said testers discovered that "ejection snapped the necks of lighter-weight test dummies."

F-35 JPO spokesman Joe DellaVedova said in an email that the ejection system in all variants of the F-35 is made by Martin-Baker Aircraft Co., a British company that specializes in ejection seats and other safety-related equipment for the aviation industry.

DellaVedova said his office is working with Martin Baker and F-35 manufacturer Lockheed Martin to fix the problem as soon as possible, but in the meantime, only one pilot in the F-35 program has been sidelined.

"(For) perspective, the temporary weight restriction only applies to one person," DellaVedova said. "We want to be safe — that’s No. 1. Martin Barker is working 24/7 to make things right."

DellaVedova said the program is "still in the developmental phase," and issues with the jet are constantly discovered and dealt with. DellaVedova cited issues with the jet’s engine, tailhook and helmet as problems that have been discovered and subsequently solved through the testing process.

"This will be solved like all the other discovery issues we’ve conquered," he said. "That’s why we test — to make things better for the warfighter. Our government and industry experts are working to develop a solution to this technical challenge and it will be resolved."

Contrary to some reports, DellaVedova said, the ejection seat issue is not related to the F-35’s high-tech helmet.

Nathan Simmons, spokesman for the 388th Fighter Wing, said the five pilots currently flying F-35 sorties at Hill all exceed the 136-pound threshold.

"It’s doesn’t affect us at all," he said. "We just don’t have anyone that light."

After receiving the Air Force’s first two combat-ready jets, pilots from Hill completed the first training missions on the jet in mid-September, conducting "mission qualification training" that included weapons employment, familiarization with the Utah Test and Training Range and other mission proficiency exercises.

Simmons said missions at Hill will continue without any restrictions.