The weight restriction for the Air Force's F-35 ejection seat has been lifted, service officials announced Monday.
"The lifting of this requires two changes: one to the seat, as well as a reduced weight helmet," said Brig. Gen. Scott Pleus, director of the service's F-35 Joint Strike Fighter program's integration office.
"Combining these changes reduce[s] the risk to lightweight pilots in both high- and low-speed ejections," said Pleus, a former F-16 Fighting Falcon pilot who soon will head to a new post at Air Combat Command.
In 2015, the Air Force put a moratorium on pilots weighing less than 136 pounds in the F-35A over high-risk injury concerns -- the combination of the fast-deploying ejection-seat chute and a lighter-weight pilot could lead to fatal neck injuries, the service said at the time.
Pleus didn't say how many pilots were impacted by this issue, but in 2015 at least one female pilot was reportedly prevented from flying the plane as a result.
The cost of retrofitting both the seat and the helmet "will be borne [by] industry," Joe DellaVedova, F-35 Joint Program Office spokesman, told Military.com.
The ejection seat can now serve any pilot weighing between 103 and 245 pounds, the Air Force said. The service currently has 107 F-35As in the fleet; 14 jets will be retrofitted per month. The final updates should be complete by January, Pleus said.
The lighter helmet design paired with delaying "the opening speed of the parachute and the cradling of the pilot's helmet with a head support panel have significantly improved the safety of the seat," he said.
Pleus said the service is retrofitting the fleet with a "lightweight seat switch and head support panel" and beginning production of the lightweight helmets.
The US16E ejection seat is manufactured by Martin-Baker.
During the weight restriction problems, the Air Force mulled switching to another seat manufacturer. Last summer, Lt. Gen. Arnold Bunch, military deputy for the Office of the Assistant Secretary of the Air Force for Acquisition, petitioned the Joint Program Office to look into cost and schedules for using United Technologies' Advanced Concept Ejection Seat 5, or ACES 5, model.
Bunch on Monday said he is rescinding his letter to JPO and UT to look into that plan.
The new lighter helmet -- the Gen-III Light made by Rockwell Collins -- is in pre-production, but will go into full production this fall, Pleus said. The external visor was removed to meet the weight criteria.
"We will now have a clear visor and a dark visor that will be interchangeable in flight," Pleus said, instead of the clear visor and the sun visor moving up and down. Some internal strapping in the helmet has also been removed to reduce weight.
"We will have our first student in that training by the end of this year, and we'll begin flying by the beginning of 2018," he said of the modified seat and helmet combo.
The Air Force is the only service to have the weight restrictions issue. While the seats are identical throughout the Air Force, Navy and Marine Corps, each has its own evaluations system -- "airworthiness criteria," as Pleus called it -- and small tweaks to the seat.
The Marine Corps' F35B-model seat, for example, "has an instantaneous ejection seat in case the airplane were to quit during a hover, which would automatically eject [the pilot] out," Pleus said.
"That capability is in every version of the seat, [but] the Air Force's version is turned off, as well as the [Navy's F-35C] carrier version," he said.