

The US Air Force (USAF) has lifted weight restrictions on F-35A pilots after testing the new ejection seat and helmet that allow pilots of all weights to escape safely in an emergency.
In 2015, USAF prevented all pilots weighing less than 136lb from flying the F-35A due to concerns about the risk during ejections in a portion of the flight envelope.
The restriction was imposed after it was found that parachute deployment/opening could cause neck injury to pilots weighing less than 136lb.
The air force required an escape system for any pilot weighing between 103lb and 245lb.
In order to allow lightweight pilots to eject safely, three modifications have been made to the escape system.
The air force has installed a switch on the seat that slightly delays parachute deployment at high speeds and decreases parachute opening forces.
The modifications also included mounting a head support panel on the rear risers of the parachute to prevent the pilot’s head from moving backwards during an ejection.
Additionally, the overall helmet weight has been decreased by reducing internal strapping material and removing an additional external visor, which minimises injury risk during parachute opening.
The new ejection seats are already being fitted onto the existing fleet, and the lightweight helmets are available in pre-production now, with plans to begin full production later this year.
The USAF has received more than 100 F-35As to date, which trained more than 400 pilots and recorded more than 40,000 flight hours.
Image: An F-35A Lightning II aircraft prepares to be refuelled. Photo: courtesy of the US Air Force photo/Staff Sergeant Kate Thornton.