Modern United States Navy Carrier Air Operations - Catapult Launch

Catapult Launch

Catapult hook up is accomplished by placing the aircraft launch bar, which is attached to the front of the aircraft's nose landing gear, into the catapult shuttle (which is attached to the catapult gear under the flight deck). An additional bar, the holdback, is connected from the rear of the nose landing gear to the carrier deck. The holdback fitting keeps the aircraft from moving forward prior to catapult firing. In final preparation for launch, a series of events happens in rapid succession, indicated by hand/light signals:

• The catapult is put into tension whereby all the slack is taken out of the system with hydraulic pressure on the rear of the shuttle.
• The pilot is then signaled to advance the throttles to full (or "military") power, and he takes his feet off the brakes.
• The pilot checks engine instruments and "wipes out" (moves) all the control surfaces.
• The pilot indicates that he is satisfied that his aircraft is ready for flight by saluting the Catapult Officer. At night, he turns on the aircraft's exterior lights to indicate he is ready.
• During this time, two or more Final Checkers are observing the exterior of the aircraft for proper flight control movement, engine response, panel security and leaks.
• Once satisfied, the Checkers give a thumbs up to the Cat Officer.
• The Cat Officer makes a final check of catapult settings, wind, etc. and gives the signal to launch.
• The catapult operator then pushes a button firing the catapult.

Once the catapult fires, the hold-back breaks free as the shuttle moves rapidly forward, dragging the aircraft by the launch bar. The aircraft accelerates from zero (relative to the carrier deck) to approximately 150 knots in about 2 seconds. There is typically wind (natural or ship motion generated) over the flight deck, giving the aircraft additional lift.