Arresting gear

An arresting gear, or arrestor gear, is a mechanical system used to rapidly decelerate an aircraft as it lands. Arresting gear on aircraft carriers is an essential component of naval aviation, and it is most commonly used on CATOBAR and STOBAR aircraft carriers. Similar systems are also found at land-based airfields for expeditionary or emergency use. Typical systems consist of several steel wire ropes laid across the aircraft landing area, designed to be caught by an aircraft's tailhook. During a normal arrestment, the tailhook engages the wire and the aircraft's kinetic energy is transferred to hydraulic damping systems attached below the carrier deck. There are other related systems that use nets to catch aircraft wings or landing gear. These barricade and barrier systems are only used for emergency arrestments for aircraft without operable tailhooks. Arresting cable systems were invented by Hugh Robinson and were utilized by Eugene Ely on his first landing on a ship—the armored cruiser , on 18 January 1911. These early systems had cables run through pulleys and attached to dead weights, such as sandbags. More modern arresting cables were tested on in June 1931, designed by Commander C. C. Mitchell. Modern U.S. Navy aircraft carriers have the Mark 7 Mod 3 arresting gear installed, which have the capability of recovering a aircraft at an engaging speed of in a distance of in two seconds. The system is designed to absorb theoretical maximum energy of at maximum cable run-out. Prior to the introduction of the angled flight deck, two systems were used (in addition to deck cables) to keep landing aircraft from running into parked aircraft further forward on the flight deck: the barrier and the barricade. If the aircraft tailhook failed to catch a wire, its landing gear would be caught by a net known as the barrier. If the aircraft caught a wire upon touchdown, the barrier could be quickly lowered to allow aircraft to taxi over it. The final safety net was the barricade, a large, net that prevented landing aircraft from crashing into other aircraft parked on the bow.