CATO
Acronym of catapult assisted takeoff.
CATO: when a jet needs a push to fly
A CATO is a mechanical system that accelerates an aircraft along a runway or flight deck to achieve flying speed in a shorter distance than it could under its own power alone. The catapult, typically hydraulic or steam-driven, couples to the aircraft's nose gear and pulls it forward at high acceleration, compressing the distance needed for takeoff from what might otherwise be 8,000 feet to 1,000 feet or less.
CATO systems are essential on aircraft carriers, where deck length is fixed and immovable. A carrier catapult must accelerate a 30-ton fighter jet from 0 to 150 knots in about 2 seconds. Steam catapults, the historical standard since the 1950s, use pressurized steam from the ship's reactors to drive a shuttle along a slot beneath the deck. Newer electromagnetic catapults (EMALS) use linear induction motors and are being installed on newer carrier classes; they offer better control and reduced shock to airframes.
On land, CATO is rarer but used by some military transport and patrol aircraft operating from short airfields. A fully loaded C-130 Hercules, for example, cannot take off from a 2,000-foot strip unaided, but with a catapult assist, it can. Ground-based catapults are almost always hydraulic, extracting much less energy per cycle than steam systems.
Maintenance demands are high. Shuttle wear, steam valve leaks, hydraulic fluid contamination, and nose gear damage from repeated violent launches are routine failure modes. Catapult officers and maintenance teams must inspect the shuttle track, coupling mechanism, and aircraft attachment points after every launch. A seized catapult grounds the entire carrier or airfield until repair.
The term assisted takeoff is the modern phrase; catapult assisted takeoff reflects the machine's origins in naval aviation of the 1920s and 1930s, when gunpowder and compressed air catapults first launched wheeled aircraft from warships. The acronym CATO has endured in fleet maintenance documentation and training materials, though you will hear aircrews and deck personnel say simply the cat.