Arresting gear
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.
This classic system of hydraulic arrest is now being supplanted by one using electromagnetics where the energy absorption is controlled by a turbo-electric engine.
Once the arresting gear stops the aircraft, the pilot brings the throttles back to idle, raises the hook and taxies clear.
In addition to American CVNs (nuclear aircraft carriers), the French Charles de Gaulle, the Russian Admiral Kuznetsov, the Chinese Liaoning, Shandong and Fujian as well as the Indian Vikramaditya and Vikrant are active or future aircraft carriers installed with arresting gear.
Land-based military airfields operating fighter or jet trainer aircraft also use arresting gear systems, although they are not required for all landings.
Overrun gear consisting of hook cables or elastic nets known as barriers are commonly used as a backup system.
On some land-based airfields where the overrun area is short, a series of concrete blocks referred to as an engineered materials arrestor system (EMAS) is used.
Unlike other types of arresting gear, EMAS is also used at some civilian airports where the overrun area is shorter than would normally be allowed.
[7] Individual cables are often removed and left "stripped" in order to perform maintenance on other components of the arresting gear during aircraft recoveries (using other, on line, systems).
Wire supports raise the deck pendants several inches so that they may be picked up by the tailhook of a landing aircraft.
The wire supports on carriers are merely curved steel leaf springs that can flex to allow an aircraft to taxi over the installed deck pendant.
The pendant (arresting wire) is "swaged" (attached) to the purchase cable by means of a loop created with zinc heated to 1,000 °F (540 °C).
[2]: 56 [6] On land based systems, heavy nylon tapes are used in place of purchase cables, but they serve the same function.
In 1957 the concept of a piston being pulled through a tube of water was first purposed as a cheap arrest gear system for land airbases.
[9] In the early 1960s, the British took this basic concept and developed a spray-type arrest gear system for both land and sea use.
On American Nimitz-class carriers, hydro-pneumatic systems are used, each weighing 43 short tons (39 t), wherein oil is hydraulically forced out of a cylinder by a ram connected to the purchase cable, through a control valve.
In certain cases, usually aircraft malfunctions, which affect approach speed, a "single weight setting" is used to ensure proper energy absorption by the system.
[citation needed] Permanent and expeditionary land based systems usually consist of two arresting engines located on either side of the runway.
The arresting engines apply braking force to reels holding the purchase tapes, which in turn slow the aircraft and bring it to a stop.
The turbulence generated in the water/glycol mixture by the turbine during the arrestment provides the resistance to slow the reel and stop the aircraft.
[citation needed] Electromagnets are being used in the new Advanced Arresting Gear (AAG) system on American aircraft carriers.
The current system is unable to capture unmanned aerial vehicles (UAVs) without damaging them due to extreme stresses on the airframe.
Rigging the barricade is routinely practiced by U.S. carrier flight deck personnel; a well trained crew can accomplish the task in under three minutes.
Barricade engagements are rare, as tailhooks are designed to be extremely fail-safe, and an aircraft returning from combat with such severe damage would likely not be able to land.
