Aircraft Catapult

An aircraft catapult is a device used to launch aircraft from ships—in particular aircraft carriers—as a form of assisted take off. It consists of a track built into the flight deck, below which is a large piston or shuttle that is attached through the track to the nose gear of the aircraft, or in some cases a wire rope called a catapult bridle is attached to the aircraft and the catapult shuttle.

The ramps at the catapult ends on some aircraft carriers are used to catch the ropes so they can be reused; bridles have not been used on U.S. aircraft since the end of the Cold War, and all U.S. Navy carriers commissioned since then have not had the ramps. The last U.S. carrier commissioned with a bridle catcher was USS Carl Vinson; starting with USS Theodore Roosevelt the ramps were deleted. During Refueling and Complex Overhaul refits in the late 1990s–early 2000s, the bridle catchers were removed from the first three Nimitz-class aircraft carriers. USS Enterprise is the last U.S. Navy operational carrier with the ramps still attached.

At launch, a release bar holds the aircraft in place as steam pressure builds up, then breaks (or "releases"; older models used a pin that sheared), freeing the piston to pull the aircraft along the deck at high speed. Within about two to four seconds, aircraft velocity by the action of the catapult plus apparent wind speed (ship's speed plus or minus "natural" wind) will be sufficient to allow an aircraft to fly away, even after losing one engine.