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Tailhook
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Aircraft's tail hook catching the wire while landing on an aircraft carrier
F-15 tailhook. Most USAF tactical jet aircraft have tailhooks for emergency use.

A tailhook, arresting hook, or arrester hook is a device attached to the empennage (rear) of some military fixed-wing aircraft. The hook is used to achieve rapid deceleration during routine landings aboard aircraft carrier flight decks at sea, or during emergency landings or aborted takeoffs at properly equipped airports.[1]

The tailhook was first demonstrated at sea on 18 January 1911 by the aviator Eugene Ely, having successfully landed aboard the armored cruiser USS Pennsylvania with the aid of the device. It was not until the early 1920s that a practical system, paired with deck-mounted arresting gear, was devised and put into use. During the 1930s, numerous vessels were thus equipped, permitting the use of increasingly heavy combat aircraft at sea during the Second World War. Following the introduction of jet-powered aircraft during the 1950s, arrestor technology was further advanced to permit aircraft operating at greater speeds and weights to land aboard aircraft carriers. The system has continued to see widespread use into the twenty-first century.

History

[edit]
F/A-18C tailhook with arresting wire

On 18 January 1911, the aviator Eugene Ely flew his Curtiss pusher airplane from the Tanforan airfield in San Bruno, California, and landed on a platform on the armored cruiser USS Pennsylvania anchored in San Francisco Bay,[2] in the first recorded shipboard landing of an aircraft. This flight was also the first ever to use a tailhook system, which had been both designed and built by the circus performer and aviator Hugh Robinson. Following the flight, Ely remarked to a reporter that: "It was easy enough. I think the trick could be successfully turned nine times out of ten." Roughly four months later, the United States Navy would requisition its first airplane, an occasion often viewed as a milestone of naval aviation.[2]

While the system initially drew only limited attention, there was greater recognition of its merits following the outbreak of the First World War.[2] Naval planners acknowledged that, in order for airplanes to be viable naval assets, they would have to be able to both take off from and land on ships. During the Great War, the number of aviators of the United States Navy rose from 38 to 1,650, which engaged in numerous duties in support of the Allies, specialising in combat air patrols and submarine spotting.[2] The capabilities of naval aviation expanded greatly during the late 1910s and early 1920s.[2] The first practical tail hook and arrestor gear arrangement was devised during this time; on 1 April 1922, the US Navy issued a request for the design of an arresting gear to equip a pair of aircraft carriers, the USS Lexington and USS Saratoga.[3]

During early 1930, the US Navy began development of an adjustable hydraulic-based arresting gear arrangement, which proved capable of absorbing the energy of aircraft landing not only at higher speeds but greater weights as well.[3] As military aircraft continued to grow in terms of both weight and sortie rates during the Second World War, naval air wings were compelled to continue innovating and improving their aircraft recovery systems. Throughout the 1950s, as a consequence of the introduction of jet aircraft to operations aboard aircraft carriers, both the landing speeds and tailhook loads increased substantially.[3]

The tailhook of a T-45

The US Navy developed and operated a test rig throughout the 1950s, consisting of a car, guided by a concrete I-beam and propelled by a pair of jet engines. At the end of a one-mile run, the tailhook under test would engage an arresting wire, while the I-beam guide gradually widened to slow down the test car after it passed the arresting wire, acting as a safeguard in the event of arrestor failure. The test rig was capable of simulating different aircraft weights and speeds, the former being adjusted by adding or subtracting steel plates that were loaded onto the modified car.[4] During 1958, further testing took place using an arrangement of four Allison J33 turbojet engines.[5] These trials supported efforts to develop increasingly effective arrestor gear that was suited for the larger and more powerful jets entering naval aviation at that time.[5]

While the tailhook is predominantly operated in a naval context, numerous land-based aircraft have also been fitted with them to assist with slowing down landings during emergencies. One highly unorthodox incident, known as "Pardo's Push", occurred during the Vietnam War in March 1967, involving a United States Air Force McDonnell Douglas F-4 Phantom II piloted by Bob Pardo assisting a second heavily damaged Phantom II in exiting the combat zone by pushing his aircraft against the other's deployed tailhook, reportedly halving its rate of descent temporarily.[6]

In the twenty-first century, the tailhook has remained a part of the principal means of landing aircraft at sea for several navies, including the US Navy. During the 2000s, the Dassault Rafale, a French multirole fighter, became the only non-US fighter type cleared to operate from the decks of US carriers, using catapults and their arresting gear, as demonstrated in 2008 when six Rafales from Flottille 12F integrated into the USS Theodore Roosevelt Carrier Air Wing interoperability exercise.[7] During the 2010s, new software trialled with the Boeing F/A-18E/F Super Hornet fighter reportedly showed promise in simplifying carrier landings.[8]

During flight testing of the new Lockheed Martin F-35 Lightning II, one of the serious deficiencies that necessitated redesigns and delays was the failure of the navy's F-35C variant to catch the arresting wire in all eight landing tests; the tail hook had to be redesigned over a two-year period.[9][10] Deficiencies have also been identified with the land-based F-35A's emergency tailhook.[11] On 3 November 2014, the first successfully arrested landing of the F-35C was performed.[12]

Description and operation

[edit]
Man inspecting an F/A-18 tailhook prior to launch

The tailhook is a strong metal bar, with its free end flattened out, thickened somewhat, and fashioned into a claw-like hook. The hook is mounted on a swivel on the keel of the aircraft, and is normally mechanically and hydraulically held in the stowed/up position. Upon actuation by the pilot, hydraulic or pneumatic pressure lowers the hook to the down position. The presence of a tailhook is not evidence of an aircraft's aircraft carrier suitability. Carrier aircraft hooks are designed to be quickly raised by the pilot after use.

A large number of land-based fighters are also outfitted with tailhooks, which are intended for use in case of a brake/tire malfunctions, aborted takeoffs, or other emergencies. Land-based aircraft landing gear and tailhooks are typically not strong enough to absorb the impact of a carrier landing,[13] and some land-based tailhooks are held down with nitrogen pressure systems that must be recharged by ground personnel after actuation.[13]

Arresting gear

[edit]
An F/A-18 makes an arrested landing aboard a US aircraft carrier
Main article: Arresting gear

Both carrier- and land-based arresting gear consists of one or more cables (aka “arresting wires” or “cross deck pendants”) stretched across the landing area and attached on either end to arresting gear engines through “purchase cables”.[14] In a typical carrier deck configuration, a total of four arrestor wires are present. The tailhook's function is to snag one of these cables, preferably the third of the four available, in order that the resistance provided by the arrestor gear can be conveyed to the aircraft, enabling it to decelerate more rapidly.[14]

Method

[edit]
MiG-29K with hook down

Prior to making an "arrested landing", the pilot lowers the hook so that it will contact the ground as the aircraft wheels touch down. The hook then drags along the surface until an arresting cable, stretched across the landing area, is engaged. The cable lets out, transferring the energy of the aircraft to the arresting gear through the cable. A "trap" is often-used slang for an arrested landing. An aircraft which lands beyond the arresting cables is said to have "boltered." Occasionally, the tailhook bounces over one or more of the wires, resulting in a "hook skip bolter."[15]

In the case of an aborted land-based takeoff, the hook can be lowered at some point (typically about 1000 feet) prior to the cable. Should a tailhook of an aircraft become inoperative or damaged, naval aviators have limited options: they can divert to shore-based runways if any are within range, or they can be "barricaded" on the carrier deck by a net that can be erected.[3]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Tailhook

View on Grokipedia
from Grokipedia
A tailhook, also known as an or , is a retractable mechanical device attached to the (rear section) of , designed to engage with cables on an 's to enable rapid deceleration during landing. This system allows heavily laden carrier-based planes, often traveling at speeds exceeding 150 , to come to a complete stop within approximately 300 feet by snagging one of several taut wires connected to hydraulic arrestors below the deck. The tailhook's origins trace back to the dawn of , with its first practical use occurring on January 18, 1911, when American aviator Eugene B. Ely successfully landed a Curtiss pusher biplane on the armored cruiser USS Pennsylvania in . The arresting system employed consisted of 22 parallel manila ropes weighted by sandbags, which were caught by a pioneering tailhook assembly—steel hooks mounted on the aircraft's undercarriage—invented by aviator and circus performer Hugh Robinson. This milestone demonstrated the feasibility of shipboard aircraft operations and laid the foundation for modern carrier aviation, evolving from rudimentary rope-and-sandbag setups to sophisticated retractable hooks capable of withstanding forces equivalent to several times the aircraft's weight. Modern systems, like the electromagnetic Advanced Arresting Gear on Gerald R. Ford-class carriers (operational as of 2017), continue to enhance performance. In operation, pilots approach the carrier at a precise glide slope, guided by optical landing systems, and extend the tailhook just before to target one of several arresting wires (typically the third on carriers with four wires), spaced about 50 feet apart, which provides the optimal balance of safety and effectiveness. The engaged wire activates hydraulic cylinders that absorb the , decelerating the from landing speed to a halt in mere seconds, while pilots maintain full to enable a "bolter"—a —if the hook misses. Tailhooks are essential to U.S. and allied naval operations, appearing on such as the F/A-18 Hornet, F-35C Lightning II, and historical models like the , and even on some land-based military jets for emergency arrested landings on shortened runways. Over the decades, designs have advanced to include "stinger" configurations for better stability and materials that endure extreme stresses, underscoring the tailhook's enduring role in enabling from sea.

History

Early Experiments

Eugene Burton Ely, an American aviation pioneer born in 1886, played a pivotal role in early shipboard aviation experiments as a test pilot for Glenn Curtiss. On November 14, 1910, Ely achieved the first successful takeoff from a warship, launching his Curtiss pusher biplane from a temporary wooden platform installed on the bow of the scout cruiser USS Birmingham in Hampton Roads, Virginia. This feat, achieved from a temporary wooden platform installed on the bow of the scout cruiser USS Birmingham in Hampton Roads, Virginia, demonstrated the feasibility of aircraft operations from naval vessels but highlighted the need for safe recovery methods. Building on this success, Ely conducted the first tailhook landing on January 18, 1911, aboard the armored cruiser USS Pennsylvania anchored in San Francisco Bay. Flying a modified Curtiss Model D pusher biplane equipped with hooks attached to the landing gear—designed by aviator Hugh Robinson—Ely approached at approximately 40 mph (64 km/h) and engaged a rudimentary arresting system of 22 manila hemp cables stretched across a 133-foot wooden platform. Each cable, spaced about 3 feet apart and raised slightly off the deck, was anchored at both ends by 50-pound sandbags that provided frictional resistance to decelerate the aircraft, bringing it to a stop within the platform's length. Ely then taxied to the forward deck and took off successfully later that day, completing the round-trip demonstration. Early tailhook experiments faced significant challenges, including the imprecise positioning required for the hooks to catch the cables amid crosswinds and the ship's motion, even when anchored. The system's reliance on friction from sandbag drag, rather than any hydraulic or mechanical damping, limited control and risked cable snaps or hook misses, as the setup lacked tension adjustment mechanisms. These rudimentary wires and bags, while proving the concept, underscored the experimental nature of the technology and paved the way for more reliable naval arresting gear in subsequent decades.

Development for Naval Aviation

Following the foundational experiments by Eugene B. Ely in 1911, the U.S. Navy pursued organized development of arresting gear to enable reliable carrier operations. On April 1, 1922, the Navy issued descriptive specifications for an advanced arresting system, outlining transverse wires stretched across fore-and-aft wires connected to hydraulic brakes, which laid the groundwork for hydraulic arresting gear installations on future carriers like USS Lexington (CV-2) and USS Saratoga (CV-3). This initiative, driven by the Bureau of Aeronautics, addressed the limitations of earlier weight-based systems and aimed to safely decelerate aircraft during deck landings. In the mid-1920s, key advancements focused on wire-and-pulley systems incorporating purchase cables to enhance energy absorption. These were rigorously tested aboard USS Langley (CV-1), the Navy's first aircraft carrier, where athwartship wires engaged the aircraft's tailhook and routed through pulleys to drag weights or hydraulic cylinders fore and aft, progressively slowing the plane. Initial installations on Langley in 1922 used sandbag weights, but by 1925, refinements included multiple wire arrays to handle varying aircraft weights and speeds, marking a shift toward standardized procedures. Alfred M. Pride's design innovations during these tests proved instrumental in transitioning from experimental setups to operational reliability. The first operational carrier landings using tailhooks occurred in March 1925 during Fleet Problem V, when aircraft from USS Langley conducted scouting missions and recoveries off the California coast, demonstrating the system's effectiveness in fleet exercises. These landings involved VE-7 and Aeromarine 39-B aircraft snagging the wires at speeds up to 50 knots, with the pulley systems successfully arresting momentum without structural failure. During the 1930s, arresting gear underwent significant refinements to accommodate higher landing speeds and heavier aircraft, including stronger tailhooks forged from high-tensile steel to withstand increased loads. Hydraulic systems replaced earlier weight mechanisms on Langley by May 1933, providing adjustable damping for speeds exceeding 60 knots, as tested at Naval Air Station Hampton Roads. Integration with catapult launches advanced concurrently, with flush-deck hydraulic catapults (Mark I) installed on carriers like USS Yorktown (CV-5) and USS Enterprise (CV-6) by 1937, allowing synchronized launch and recovery cycles that boosted sortie rates during exercises. These enhancements solidified tailhook technology as essential for interwar naval strategy.

Advancements for Jet and Modern Aircraft

Following , the advent of necessitated significant redesigns in tailhook systems to accommodate higher landing speeds and greater during arrested recoveries. Early , such as the , which entered U.S. Navy service in 1949 as the first straight-wing carrier-based jet fighter, required reinforced tailhooks capable of withstanding impacts at speeds exceeding 100 knots—roughly 115 miles per hour—compared to the lower velocities of propeller-driven planes. These redesigns incorporated stronger components to endure the increased stresses, ensuring reliable engagement with arresting wires while maintaining structural integrity during carrier operations. A pivotal advancement in the was the integration of tailhook systems with angled carrier decks, first trialed on the USS Antietam (CVA-36) in 1952 after modifications based on British innovations. This configuration angled the landing strip approximately 10.5 degrees from the ship's axis, enabling simultaneous aircraft launches from the bow while recoveries occurred astern, without the risk of a missed wire causing a collision with parked planes. Tailhooks remained central to this evolution, as the angled layout minimized deck blockage from arrested landings, allowing for continuous multiple engagements and safer, more efficient flight operations on carriers like the Essex-class vessels adapted for jets. In the , tailhook designs have evolved to support stealth and advanced , exemplified by the F-35C Lightning II carrier variant. On November 3, 2014, the F-35C achieved its first arrested landing aboard the (CVN-68) off the coast of , , marking a milestone in integrating fifth-generation stealth fighters with carrier . The aircraft's tailhook is retractable, designed to stow flush within the to preserve low-observable stealth characteristics by minimizing cross-section when not in use. Overall, the F-35C incorporates extensive composite materials, which comprise approximately 35% of the airframe's structural weight, enhancing and payload capacity without compromising the tailhook's for high-speed recoveries. Further refinements in the included a shift toward pneumatic actuation mechanisms in some tailhook systems, enabling faster deployment times—under two seconds from stowage to extension—to match the rapid operational tempos of Cold War-era carriers. This was particularly evident in aircraft like the , where pneumatic systems provided reliable, high-speed lowering of the hook under varying flight conditions, improving pilot confidence during high-angle-of-attack approaches. These developments prioritized compatibility with emerging stealth requirements, as seen in later designs that balanced actuation speed with aerodynamic and radar-evading profiles.

Design and Construction

Core Components

The tailhook assembly is mounted on the aircraft's , positioned far aft along the centerline of the to provide clearance for arresting cables relative to the engines and horizontal stabilizers during engagement. This placement ensures the hook extends below the aircraft's wheels when deployed, integrating directly with the aft structure via a reinforced attach fitting that transmits deceleration loads to the and backup frames. The mounting typically involves bolting or hinging the assembly to fuselage channels or a dedicated plate, designed to endure peak loads exceeding 200,000 pounds, equivalent to 3-4g forces for typical carrier landing weights. The core of the assembly features a curved shank forming a metal blade-like hook, approximately 3 feet in length, with a U-notched or grooved end for secure cable capture. This shape includes a replaceable hook point with an arcuate groove. The hook pivots on a mechanism linked to controls, allowing the pilot to raise or lower it as needed, with actuation powered by for reliable positioning.

Materials and Actuation Mechanisms

The tailhook's hook blade and shank are primarily fabricated from high-strength, low-alloy , selected for their exceptional toughness, fatigue resistance, and ability to endure the extreme dynamic loads encountered during arresting operations, often exceeding 200,000 pounds of force. These alloys provide a balance of and , enabling the component to absorb high-impact stresses without fracturing, as demonstrated in naval aircraft like the T-45 Goshawk where specialized Ferrium M54 steel variants have been implemented for hook shanks to enhance resistance and extend service life. Actuation of the tailhook relies on hydraulic cylinders integrated with the aircraft's primary hydraulic system, operating at pressures around 3,000 psi to ensure rapid and reliable deployment. These cylinders extend or retract the hook mechanism, allowing pilots to prepare for carrier landings efficiently without compromising flight stability. The system's design draws power directly from the aircraft's engines or , providing consistent force for the pivot and extension motions essential to positioning the hook precisely below the . To mitigate wear from repeated engagement with steel arresting wires, the tailhook's contact surfaces receive hard chrome plating, which imparts a hardness exceeding 65 Rockwell C and a low coefficient of friction to prevent slippage and galling during high-speed captures. This coating, applied via electrodeposition, also offers corrosion protection in marine environments, though ongoing Department of Defense initiatives explore alternatives like nanocrystalline cobalt-phosphorus alloys to replace hexavalent chromium processes for environmental compliance. Durability in the tailhook's pivot joints is achieved through sealed bearings, ensuring smooth and minimal across thousands of flight hours. These bearings incorporate integrated seals to exclude contaminants like saltwater and debris, supporting the joint's role in absorbing torsional forces during deployment and retraction.

Operation and

Engagement and Arresting

The engagement and arresting process for tailhook-equipped during carrier landings is a precisely coordinated sequence that relies on pilot actions, visual signals, and the carrier's system. Prior to entering the approach pattern, the pilot arms the tailhook via cockpit controls as part of standard pre-landing preparations, ensuring the mechanism is ready for deployment. This arming occurs well before the final approach to allow verification of system status and compliance with aircraft-specific NATOPS procedures. Once armed, the tailhook remains retracted until signaled for lowering. As the aircraft descends into the landing groove—typically 15 to 18 seconds from touchdown—the pilot reduces to achieve the on-speed , maintaining a glide slope of 3.5 to 4 degrees guided by the Precision Approach Landing System (PALS) or the . The pilot lowers the tailhook during the approach configuration, typically after the carrier break, ensuring it is extended before entering the landing groove. The pilot activates the lowering mechanism, often a dedicated switch or lever, causing the hook to extend hydraulically or pneumatically to hang inches above the deck surface, positioned to snag the wires without dragging prematurely. Upon main gear , the extended tailhook snags one of the four transverse cross-deck pendants (arresting wires) stretched across the , spaced about 50 feet apart, with pilots trained to target the third wire for balanced deceleration. This , known as a "trap," transfers the aircraft's forward momentum to the engines below deck, which use hydraulic damping to absorb and halt the aircraft within 300 to 350 feet of the aim point. The process demands exact alignment and sink rate control, as the underlying energy transfer mechanism ensures rapid yet controlled stopping forces tailored to the aircraft's weight and speed. Should the tailhook fail to catch any wire—resulting in a "bolter"—the pilot immediately advances to full military power upon deck contact, retracts the hook to avoid drag, and executes a by climbing at a safe angle while maintaining wings level. The then turns to parallel the ship's base recovery course (BRC) at 600 feet altitude before rejoining the traffic pattern for another attempt, with the LSO providing corrective debriefing via radio. This abort sequence minimizes risk and allows rapid recovery resets by deck crews.

Physics of Deceleration

The physics of deceleration in tailhook arresting systems centers on the rapid dissipation of an aircraft's through a of mechanical tension and absorption. In traditional MK7 systems, upon engagement, the tailhook snags a cross-deck pendant wire, which transfers the aircraft's —calculated as 12mv2\frac{1}{2} mv^2, where mm is the aircraft and vv is the landing speed—directly to the arresting gear's hydraulic dampers. For a typical carrier landing, this involves speeds around 150 mph (approximately 67 m/s) for aircraft like the F/A-18, resulting in substantial energy that must be absorbed over a short distance to prevent overrun. The system achieves this by pulling the wire, which rotates large sheaves connected to rotary hydraulic engines filled with fluid; as the engines spin, the fluid's viscosity generates resistance, converting into heat via turbulence and damping. Newer systems like the Advanced Arresting Gear (AAG) on Ford-class carriers use water turbines instead of hydraulic fluid, achieving similar deceleration profiles as of 2025. This process halts the aircraft in 2-3 seconds, with simulations showing durations of about 3.5 seconds for a 25,000 kg aircraft at 65 m/s. The forces involved in this deceleration are distributed primarily through the tailhook and undercarriage, with peak loads typically reaching 1.5 to the aircraft's weight to ensure structural integrity. For an F/A-18 with a landing weight of around 34,000 lbs, this translates to peak forces of 51,000 to 68,000 lbs, though dynamic models indicate higher instantaneous loads up to approximately 157,000 lbs (698 kN) during engagement due to wave propagation in . These forces arise from the wire's tension, generated by the arresting engines, which maintain a controlled pull-back mechanism. between the wire and sheaves, combined with the effect of the (or in AAG), ensures a relatively constant deceleration profile, avoiding excessive jolts. The overall deceleration averages 3-4 g (29-39 m/s²), with peaks up to 4 g, calibrated to the aircraft's weight and speed for safe arrestment without exceeding pilot or tolerances. The stopping can be derived from the kinematic d=v22ad = \frac{v^2}{2a}, where vv is the initial landing speed and aa is the average deceleration, typically around 10 m/s² (approximately 1 g) in simplified models but higher (up to 30 m/s² or 3 g) in practice for carrier operations. For a 67 m/s landing speed and a≈30a \approx 30 m/s², this yields a of about 75 meters, aligning with observed arrest lengths of 85-105 meters in multibody simulations of the MK7 arresting gear. This underscores the precision required: higher speeds or lower would extend dd beyond the deck's limits, while excessive aa risks structural . The system's prioritizes uniform energy absorption to minimize peak stresses on the wire (up to 609 MPa) and hook, ensuring reliability across varied conditions.

Applications and Variations

Carrier-Based Naval Aircraft

Carrier-based naval aircraft rely on tailhooks specifically engineered for the demanding environment of operations, where rapid deceleration is essential for safe landings on short flight decks. The F/A-18 Hornet employs a retractable tailhook positioned near the aircraft's , designed to engage arresting wires reliably during routine carrier recoveries. This configuration ensures structural integrity under high-impact stresses, with the hook fabricated from high-strength alloy steels like AMS 6516 chromium-vanadium grades, which provide excellent fatigue resistance and corrosion protection in marine conditions. In contrast, the F-35C Lightning II features a retractable tailhook that deploys, engages, and stows hydraulically under electronic control, minimizing aerodynamic drag and preserving the aircraft's stealth profile when not in use. This design adaptation supports the F-35C's role as a carrier-optimized stealth fighter, allowing seamless integration into naval strike missions while maintaining low during flight. Both the F/A-18 and F-35C tailhooks are reinforced with , such as ultra-high-strength Ferrium M54 , to withstand saltwater exposure and prevent over extended deployments. Naval tailhooks are further adapted for the corrosive maritime atmosphere and rigorous operational tempo of carrier decks, incorporating protective coatings like plating or amorphous alternatives to shield against saltwater degradation and ensure longevity through high-cycle fatigue from repeated arrests. These components are built to endure intensive use, with refurbishment programs addressing wear from hundreds of landings per deployment, thereby supporting sustained readiness in fleet operations. Tailhooks on are integrated with the U.S. Navy's Mk-7 system, which uses hydraulic engines and wire ropes to decelerate incoming jets from approach speeds of up to 150 knots to a within approximately 350 feet of deck contact. This compatibility ensures precise energy absorption, with the tailhook engaging the deck pendant to transfer kinetic forces to the engines below deck, enabling efficient recoveries across Nimitz- and Ford-class carriers. Interoperability extends beyond U.S. designs, as demonstrated by the French Navy's Rafale M, which successfully conducted carrier operations aboard the USS Theodore Roosevelt in 2008 during a joint exercise, with its tailhook engaging American to highlight cross-nation compatibility for multinational .

Land-Based and Emergency Use

Land-based arresting systems, such as the BAK-12 and BAK-14, extend the utility of tailhooks on non-carrier aircraft like the F-15 Eagle and F-16 Fighting Falcon for emergency situations on . These systems employ a retractable cable or pendant that the aircraft's tailhook engages during overruns or short-field landings, providing rapid deceleration through hydraulic rotary friction energy absorbers. Introduced in 1962, the BAK-12 has become the standard U.S. arresting system, installed at numerous bases to mitigate risks from insufficient runway length or failures. In emergency deployments, pilots manually lower the tailhook to catch the arresting cable, often at the end of the , allowing to stop within a shortened distance—typically under 1,000 feet for fighters. For instance, the F-22 Raptor relies on its tailhook primarily for such land-based emergencies, as demonstrated in real-world incidents where it successfully engaged a BAK-12 system during an in-flight malfunction. Unlike carrier variants, land-based tailhooks are optimized for infrequent use, featuring simpler manual actuation mechanisms without the reinforced durability needed for repeated high-stress engagements on aircraft carriers. Supporting infrastructure like the BAK-14 provides bidirectional cable support, retracting below the surface when not in use to avoid interfering with routine operations. Portable versions of these systems, including mobile BAK-12 kits, enable rapid deployment for or contingency operations on austere runways, contrasting with the fixed installations typical of naval environments. This adaptability has proven essential for U.S. Air Force fighters operating from joint-use or civil airfields, where retractable cable supports like the BAK-14 ensure compatibility without compromising civilian traffic. Overall, these land-based applications prioritize reliability in rare, high-stakes scenarios, enhancing safety for tactical beyond maritime settings.

Safety Considerations

Common Malfunctions

One common malfunction in tailhook systems involves failure to properly engage or retract, often stemming from issues in the hydraulic actuation mechanism or associated sensors that control deployment. Hydraulic leaks can compromise the system's ability to lower the hook reliably during approach, while sensor faults may prevent timely retraction post-arrestment, potentially leading to drag or interference in subsequent operations. These issues contribute to overall arresting gear engagement success rates. Wire slippage represents another frequent issue, where the tailhook fails to securely catch the arresting cable, resulting in a "hot" pass (high-speed overrun) or bolter (). This typically occurs due to off-center landings—up to 10 feet or starboard—causing the cable to abrade against the hook as the system pulls the toward the centerline, exacerbated by worn cable coatings or suboptimal engagement angles. The low diameter-to-diameter (D/d) ratio during the final bend around the hook further accelerates wear on cross-deck pendants, which are replaced after roughly 125 cycles. Structural fatigue is a primary long-term concern, manifesting as cracks in pivot points and hook shanks after repeated stress cycles from flexing, , and exposure. In T-45 tailhooks, made of high-strength steels like AF1410, cracks often initiate at pits (depths of 0.010–0.0368 inches) or fillet radii under tensile loads, due to reduced life from environmental factors like NaCl or SO₂ salt fog. Detection relies on non-destructive testing methods, including ultrasonic angle-beam backscattering, white-light (resolving 3 nm vertically), and replication techniques, which identify surface voids (20–100 μm depth) and stress concentrations (Kt_eff of 1.111–1.112). To mitigate these risks, tailhook systems incorporate measures such as dual hydraulic lines, allowing continued operation if one fails, alongside broader hydraulic backups that prevent total loss from leaks or faults. protocols mandate inspections and component replacements at defined intervals, with F/A-18 tailhook subcomponents turned in after 43 traps and full overhauls every 300 traps (extendable to 400–500 on a case-by-case basis), ensuring structural amid high-cycle demands.

Notable Incidents and Improvements

One of the most remarkable uses of the tailhook in an emergency situation occurred on March 10, 1967, during the , in what became known as "." U.S. Bob , flying an F-4 Phantom II from the 8th Tactical Fighter Wing, witnessed his wingman's aircraft, also an F-4 Phantom II piloted by 1st Lieutenant Earl Aman, sustain severe damage from North Vietnamese anti-aircraft fire, resulting in a massive fuel leak and inability to reach a scheduled mid-air refueling tanker. With the damaged plane unable to maintain altitude and at risk of crashing in enemy territory, Pardo instructed Aman to lower the tailhook—a feature originally designed for carrier arrested landings but present on Phantoms for emergency arrests. Pardo then maneuvered his aircraft to position its forward canopy edge against the steel rod of the lowered tailhook, effectively pushing the stricken F-4 southward toward . This unconventional technique halved the descent rate of Aman's plane, allowing both crews to cross into friendly airspace approximately 65 miles from the border, where they ejected safely and were rescued by pararescue teams. Pardo's actions, initially reprimanded for risking his own aircraft, were initially awarded the in 1967 and later upgraded to the Air Force Cross in 1989, underscoring the tailhook's unexpected versatility in combat rescue scenarios. Post-incident analyses in the drove significant advancements in tailhook technology, including the adoption of automated hook position sensors and reinforcements in select naval designs. These sensors, integrated into flight control systems, provided real-time monitoring of hook deployment and stress levels, enabling pilots to receive warnings during approach and reducing the risk of in-flight malfunctions. Composite elements, such as carbon-fiber reinforced struts, were incorporated to lighten the assembly while maintaining high tensile strength, contributing to an overall decrease in tailhook-related failures during carrier qualifications. A tragic example of an aircraft crash involving an F/A-18F Super Hornet (BuNo 165877) from Strike Fighter Squadron 122 occurred on April 6, 2011, during a training flight near , . The incident led to loss of control and a crash in a remote field, resulting in the deaths of both crew members, Matthew Ira Lowe and Nathan Hollingsworth Williams. The incident prompted the (in coordination with the ) to issue mandatory inspections for all F/A-18 variants, emphasizing non-destructive testing for high-cycle components to prevent recurrence.

References

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  15. https://navyhistory.org/2020/04/father-of-the-trap/
  16. https://www.patriotspoint.org/news/centennial-naval-aviation-first-fleet-use-aircraft-carrier
  17. https://airandspace.si.edu/air-and-space-quarterly/winter-2022/americas-first-aircraft-carrier
  18. https://www.history.navy.mil/content/dam/nhhc/research/histories/naval-aviation/pdf/PART04.PDF
  19. https://www.usni.org/magazines/proceedings/2011/may/ten-most-pivotal-events-us-naval-aviation
  20. https://www.history.navy.mil/content/history/museums/nmusn/explore/photography/aircraft-us/aircraft-usn-f/f9f-panther.html
  21. https://www.defensemedianetwork.com/stories/naval-aviation-centennial-from-props-to-jets-and-angled-decks/
  22. https://www.cpf.navy.mil/Newsroom/News/Article/2749537/f-35c-completes-first-arrested-landing-aboard-aircraft-carrier/
  23. https://www.bizjournals.com/washington/blog/fedbiz_daily/2013/04/lockheed-comes-up-with-new-design-for.html
  24. https://www.compositesworld.com/articles/skinning-the-f-35-fighter
  25. https://trace.tennessee.edu/context/utk_gradthes/article/11784/viewcontent/Thesis98.G87.pdf
  26. https://www.flighthelmet.com/product/ACPT-A7TAILHOOK.html
  27. https://patents.google.com/patent/US2989272A/en
  28. https://media.defense.gov/2023/Jan/27/2003151013/-1/-1/0/QUESTEK_INNOVATIONS_STORY.PDF
  29. https://skybrary.aero/articles/hydraulic-systems
  30. https://www.sargentaerospace.com/hydraulic-actuators/
  31. https://serdp-estcp.mil/projects/details/a0a102e0-73bd-4c5e-8cbb-1b639c0b5c74
  32. https://apps.dtic.mil/sti/tr/pdf/AD1064242.pdf
  33. https://apps.dtic.mil/sti/tr/pdf/ADA068619.pdf
  34. https://onlinelibrary.wiley.com/doi/10.1155/2013/867012
  35. https://www.mdpi.com/2076-3417/10/4/1253
  36. https://aviation.stackexchange.com/questions/25084/what-is-the-force-exerted-by-the-catapult-on-aircraft-carriers
  37. https://illumin.usc.edu/taking-off-and-landing-on-an-aircraft-carrier/
  38. https://www.navair.navy.mil/node/26021
  39. https://aviation.stackexchange.com/questions/32169/what-is-the-tailhook-on-naval-aircraft-made-out-of
  40. https://www.aerospacetestinginternational.com/news/defense/f-35-tailhook-testing-at-edwards-afb.html
  41. https://transportation.northwestern.edu/docs/collaboration/business-advisory-council/meeting-archive/2011-spring/2011.04.06.BAC_Olson_Presentation.pdf
  42. https://www.navysbir.com/n09_3/N093-180.htm
  43. https://www.globalsecurity.org/military/library/policy/navy/nrtc/14310_ch3.pdf
  44. https://www.aircraftarresting.com/systems.html
  45. https://www.acc.af.mil/News/Article-Display/Article/1401502/bak-12-brakes-jets/
  46. https://themobilityforum.net/2021/09/02/chain-reaction-the-barrier-between-life-and-death/
  47. https://www.twz.com/41962/watch-this-f-22-raptors-tailhook-catch-the-arresting-wire-during-an-emergency-in-hawaii
  48. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_150_5220_9B_aircraft_arresting_system.pdf
  49. https://electro-mechanicalsystems.curtisswright.com/arresting-systems/emergency-arresting-systems-for-military-aircraft
  50. https://www.af.mil/News/Article-Display/Article/3839374/bak-12-installation-strengthens-slovak-partnership/
  51. https://talkbusiness.net/2023/12/arresting-system-work-begins-at-fort-smith-regional-airport/
  52. https://atecharrestors.com/fixed-systems/
  53. https://www.stle.org/files/TLTArchives/2013/06_June/Cover_Story.aspx
  54. https://news.usni.org/2019/02/13/navy-hopes-advanced-arresting-gear-will-be-ready-for-fleet-super-hornet
  55. https://www.navysbir.com/n19_2/N192-077.htm
  56. https://apps.dtic.mil/sti/tr/pdf/ADA476065.pdf
  57. https://www.navalnews.com/naval-news/2020/05/u-s-navy-navair-fix-f-a-18-and-ea-18g-arresting-hook-shortfall/
  58. https://media.defense.gov/2010/Oct/01/2001329749/-1/-1/0/ToHanoiAndBack.pdf
  59. https://apps.dtic.mil/sti/tr/pdf/ADA475727.pdf
  60. https://asn.flightsafety.org/wikibase/121575
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