"During a catapult launch the nose landing gear strut is compressed as the catapult pulls on the nose landing gear, with the hold back bar restraining the aircraft from forward movement due to engine thrust," according to a Dec. 28 Navy information paper viewed by Inside Defense. "Upon release of the hold back bar, the nose landing gear strut unloads and vertically oscillates as the aircraft accelerates towards take-off."
The motion is not only uncomfortable but the Helmet-Mounted Display and oxygen mask push back and up and down against the pilot's jaw. The jostling in the cockpit results in unreadable HMD during and immediately after launch, the paper reads.
C&P from elsewhere.