(CNN) The US Air Force announced Monday that it will end a restriction that prohibited pilots of a variant of the F-35 fighter jet from weighing less than 136 pounds.

The restrictions were put in place after testing showed lightweight pilots could suffer debilitating injuries and even death while ejecting from the aircraft.

"The Air Force is lifting the lightweight pilot restriction from our entire F-35A fleet," Brig. Gen. Scott Pleus, the Air Force's F-35 Integration Office director, told reporters at the Pentagon.

The policy change was made possible due to modifications to the pilot's helmet and the aircraft's ejection seat, according to Air Force officials. The helmet was made lighter while the opening speed of the parachute was delayed, and a head support panel was also added to prevent the pilot's head from moving backward during the ejection.

"Combined, these changes reduce the risk to lightweight pilots in both high- and low-speed ejections, and makes the F-35 ejection system one of the safest in our entire inventory," Pleus said.

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