Flight deck of USS Dwight D. Eisenhower, showing catapult layout.
Catapult launches aboard USS Ronald Reagan
CATOBAR (Catapult Assisted Take-Off But Arrested Recovery) is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier. Under this technique, aircraft launch using a catapult-assisted take-off and land on the ship (the recovery phase) using arrestor wires.
Although this system is more costly than alternative methods, it provides greater flexibility in carrier operations, since it imposes less onerous design elements on fixed wing aircraft than alternative methods of launch and recovery such as STOVL or STOBAR.
The United States Navy is developing a system to launch carrier-based aircraft from catapults using a linear motor drive instead, called the EMALS.
The catapult system in use in modern CATOBAR carriers is the steam catapult. Its primary advantage is the amount of power and control it can provide. During World War II the US Navy used a hydraulic catapult.