Structural and Technical Evolution of US Navy Aircraft Carrier Aircraft: 1945–1965

With the end of the Second World War, aviation technology underwent a paradigm shift that pushed the boundaries of piston-engined and propeller-driven aircraft. The advent of the jet engine not only increased speed and altitude capabilities but also fundamentally transformed the basic mechanical and structural principles of aircraft design. For the United States Navy (US Navy), this shift became a dual engineering challenge due to the necessity of operating on aircraft carrier decks—an environment far more complex and restrictive than land-based airfields. This period, spanning from the late 1940s to the mid-1960s, represents an evolutionary process in naval aviation during which the aircraft and the ship were redefined as a fully integrated weapon system. During this process, the increasing weights of jet aircraft, their rising approach speeds and the poor aerodynamic characteristics they exhibited at low speeds necessitated structural and engineering transformations across a wide spectrum—ranging from airframe integrity to landing gear, and from tail hook mechanisms to advanced aerodynamic solutions such as boundary layer control.

The aircraft in the cover image is an F-4S Phantom II (or a late-model modernised F-4N/J variant) serving on the USS Midway (CV-41), as indicated by its tail code (NF), the emblem on its fuselage (VF-151 ‘Vigilantes’ Squadron) and the text on the fuselage. The image perfectly captures, from a technical perspective, those critical few seconds preceding the catapult launch. We can analyse the main technical elements, operational mechanisms and systems in the photograph as follows:

‘Bridle’ System: The first element to catch the eye is the thick steel cables (bridle) extending from the aircraft’s under-fuselage/wing root attachment points (tow hooks) to the catapult carriage. Early and mid-production naval variants of the F-4 Phantom (F-4B, J, N, S) did not feature a bar that received a direct mechanical connection from the nose gear (Nose Gear Launch – NGL). Consequently, the launch was carried out by pulling the aircraft via these steel slings.

Holdback Bar: You can see the taut bar extending from beneath the aircraft’s tail/rear fuselage towards the deck. This mechanism holds the aircraft in place until the catapult is triggered when the aircraft is at full throttle (Afterburner). When the catapult is fired, a calibrated pin (release link) on this bar breaks, allowing the aircraft to be launched.

Nose Wheel Hydraulics (Tail-Down Position): The nose landing gear is extended during launch to increase the angle of attack (AOA) and provide extra lift during take-off.

Thermodynamic and Mechanical Consequences of the Transition to Jet Engines in Aeronautical Engineering

In the aerodynamic world of propeller-driven aircraft, the airflow generated by the propeller (propwash) ensured that high-energy air passed over the wing surfaces and control surfaces even at low speeds, thereby enhancing controllability. However, with the advent of jet engines, aircraft became confined to the dependent airflow (airspeed) generated solely by their own forward motion. This situation jeopardised low-speed stability, which is of vital importance when landing on a limited runway area such as an aircraft carrier. The slow response of early jet engines—particularly first-generation centrifugal and axial-flow compressors—to throttle changes (spool-up time) dramatically reduced the margin for error during pilots’ go-around manoeuvres. These technical constraints created an operational environment that required the aircraft to withstand much harsher structural impacts.

For naval aviation engineers, the main challenge was the rapidly increasing mass of jet aircraft due to their fuel consumption and high-performance requirements. Whilst an F4U Corsair had a maximum take-off weight of approximately 14,000 pounds at the end of the Second World War, by the early 1960s an F-4 Phantom II had quadrupled this weight, exceeding the 55,000-pound limit. This increase in mass led to a logarithmic rise in kinetic energy on the catapult launch and arresting systems, necessitating a recalculation of the aircraft’s ‘load paths’.

Table 1: Technical Comparison of Historical Jet and Piston-Powered Aircraft of the US Navy

Aircraft Model Engine Type Maximum Take-off Weight (lb) Approach Speed (Knots) Key Structural Innovation

F4U-4 Corsair Piston/Propeller 14,500 85 Classic Riveted Aluminium

F9F-2 Panther Early Jet 16,450 105 Reinforced Tail Hook

F3H Demon Mid-Period Jet 33,900 125 Early Use of Titanium

F-8 Crusader Supersonic Jet 34,000 120 Variable-Sweep Wing

F-4B Phantom II Heavy Interceptor 54,600 135 Boundary Layer Control (BLC)

Redesign of Structural Integrity and Load Path Engineering

The fuselage of an aircraft carrier-based jet is, in fact, a massive shock absorber built to withstand two major mechanical shocks. During a catapult launch, the aircraft accelerates from zero to approximately 140 knots in just 2.5 seconds; during this process, a longitudinal acceleration load of approximately 3.25g is exerted on the aircraft’s internal structure. This force is transmitted throughout the entire fuselage, starting from the point where the aircraft is attached to the catapult carriage.

Catapult Attachment Mechanisms and Fuselage Integration

During this period in aviation, there was a significant engineering shift in the method of transferring catapult force to the aircraft. Initially, aircraft were launched using steel cables known as ‘bridles’, which were attached to the wing roots or hooks beneath the main fuselage. However, as aircraft weights increased, the stresses placed on the aircraft’s main structure by these cables became unbalanced, causing the aircraft’s nose to exhibit a dangerous tendency to lift during launch. The ‘Nose Gear Launch’ system, developed from the mid-1950s onwards, began to address this issue by transferring the force directly to the nose gear strut and from there to the aircraft’s central structural spar.

This transition ensured that the nose gear evolved from being merely a steering unit into the primary structural element bearing the aircraft’s entire launch load. Engineers reworked the static equilibrium equations within the aircraft’s fuselage using the principle of F=m.a, Newton’s second law. In this context, the inertial forces known as ‘D’Alembert forces’ create a counteracting load on each component of the aircraft (wings, engines, munitions) during launch. To prevent these loads from bending or fracturing the aircraft’s skeleton, central keel beams have begun to be forged from massive steel or titanium blocks to withstand the stresses in the launch direction.

Arresting Stresses and Tail Section Reinforcement

The arresting process presents a stress scenario that is the exact opposite of launch. When the aircraft’s tail hook catches the steel cable, a mass of approximately 30–40 tonnes is brought to a halt within seconds. This force is transmitted as a tensile load from the point where the hook is attached towards the aircraft’s centre of gravity. In early designs, the hook was attached to the aircraft’s tail cone; however, this caused the hook to sit well below the aircraft’s centre of gravity, leading to the aircraft’s nose striking the runway with great force (nose-down pitch) during landing.

Engineers have moved to ‘Stinger’ type designs to counterbalance this moment. The Stinger design extends the lever arm by positioning the tail hook at the very rear of the aircraft, near the engine exhausts, ensuring that the braking force passes through a point closer to the aircraft’s central axis. This transition required a complete structural redesign of the tail section, with the frame (bulkhead) to which the hook was attached being secured to the main fuselage spars using massive rivets and forged fasteners. Particularly during F9F Panther tests, structural failures such as the rear fuselage—to which the hook was attached—separating from the rest of the aircraft demonstrated just how critical the material’s fatigue limits and load distribution were.

Landing Gear Engineering: High Flare Speeds and Energy Management

Landing on an aircraft carrier is structurally entirely different from glide-style landings on land runways. Instead of reducing the aircraft’s flare as they approach the deck, naval pilots ‘crash’ the aircraft onto the deck in a controlled manner. This is to ensure the aircraft does not miss the arresting wires (bolter) and that the hook makes full contact with the deck. This necessitates that the landing gear can withstand ‘sink rates’ of 20 to 23 feet per second (approximately 7 metres per second) on every landing without compromising its structural integrity.

Hydraulic Damping Dynamics in Oleo-Pneumatic Shock Absorbers

With the increasing weight of jets, conventional spring-loaded or simple hydraulic shock absorbers have become inadequate. Instead, ‘oleo-pneumatic’ (oil-gas) type shock absorbers have become standard. In this system, upon impact, the piston moves upwards, forcing the hydraulic oil through a small orifice. Whilst the resistance of the oil converts kinetic energy into heat, the compressed nitrogen gas in the upper section acts as a spring, supporting the aircraft’s weight.

One of the greatest innovations in engineering is the use of a ‘metering pin’. This variable-profile pin, located inside the shock absorber and inserted into the orifice through which the oil flows during impact, narrows the oil flow area the more the shock absorber compresses. This provides ‘variable damping’, optimising the aircraft’s impact load at every stage of landing. Particularly in heavy aircraft, the forces exerted on the landing gear can reach several times the aircraft’s empty weight.

A Revolution in Materials Science: 300M Steel and Alloy Innovations

Landing gear struts needed to withstand extreme impact loads whilst remaining light enough not to increase the aircraft’s overall weight. Developed by the International Nickel Corporation in 1952 and named ‘300M’, this ultra-high-strength low-alloy steel marked a turning point for naval aviation. 300M steel possessed an immense tensile strength of 1860 MPa (approximately 270–300 ksi). The approximately 1.5% silicon content in its composition increased the steel’s resistance to tempering, thereby providing resistance to stress corrosion cracking.

The use of 300M steel enabled an increase in load-carrying capacity despite the reduction in the dimensions of landing gear components. However, even this steel had its limitations; due to its low corrosion resistance, it required protective measures such as cadmium plating. By the late 1960s, work had begun on more advanced alloys, such as AerMet 100, which would replace this material and possess higher fracture toughness (fracture toughness).

Table 2: Mechanical and Metallurgical Comparison of High-Strength Alloys Used in Aerospace Structural Applications

Material Property AISI 4340 Steel 300M Steel AerMet 100

Tensile Strength (MPa) ~1200 1860 1965 - 2069

Fracture Toughness (KIC) Low Medium (~55 MPa√m) High (>110 MPa√m)

Primary Alloying Elements Cr, Ni, Mo Cr, Ni, Mo, Si Co, Ni, Cr, Mo

Application General Aviation 1960s Jet Landing Gear Modern Naval Jets (F/A-18E/F)

Tail Hook Technology: Bounce Control and Dashpot Mechanisms

The high speeds of jets have triggered a physical problem known as ‘hook bounce’, which prevents the aircraft from catching the arresting cables. When the tail hook strikes the runway, the impact causes it to bounce upwards, potentially causing it to clear the arresting wires. This situation poses a ‘bolter’ (failure to catch) risk, which could have fatal consequences, particularly during high-speed approaches.

Hydraulic Dashpot and Viscous Damping

The ‘dashpot’ mechanism, developed to prevent hook bounce, is a type of one-way hydraulic damper. The dashpot uses nitrogen pressure to keep the hook down (hold-down). When the hook strikes the runway, the viscous fluid (usually silicone oil) inside the dashpot offers resistance proportional to the hook’s upward velocity. This dampens the hook’s upward movement and prevents it from jumping over the cable.

From an engineering perspective, the hook design also affects the aircraft’s aerodynamic balance. The hook’s position relative to the centre of gravity determines whether the nose moves up or down at the moment of arrest. Furthermore, modern hook systems feature a complex valve system that enables the hook to automatically disengage from the cable and retract rapidly after the aircraft has been arrested.

A Revolution in Low-Speed Aerodynamics: Boundary Layer Control (BLC)

Jet aircraft require slender wing profiles to manage shock waves at high speeds (Mach 1 and above). However, these slender wings cannot generate sufficient ‘lift coefficient’ (CL) at the low speeds required for landing on an aircraft carrier. If the aircraft slows down too much, the airflow over the wing separates from the surface (stall) and the aircraft loses altitude. The most advanced technology developed to solve this problem is the ‘Boundary Layer Control’ (BLC) system.

Mechanism: Blown Flaps

The BLC system directs high-pressure air (bleed air) from the aircraft’s jet engine compressor into narrow channels running along the leading or trailing edge flaps. This air is is sprayed onto the flaps at very high speed. This ‘blowing’ process re-energises the boundary layer on the flap surface, which is moving slowly and prone to separation. As a result, the airflow can pass over the flaps without separating, even at much sharper angles.

The F-4 Phantom II was a pioneer of this system. Air from the J79 engines is fed into the system when the flaps are extended up to 45 degrees. Experimental data and flight tests have demonstrated that the BLC provides the following concrete benefits:

-Reduction in Approach Speed: The use of BLC has reduced the aircraft’s approach speed by 10 to 15 knots.

-Increased Lift: An improvement of 15–20 per cent in the maximum lift coefficient has been achieved.

-Field of View and Safety: As the same lift is achieved at lower speeds, the aircraft’s nose needs to be raised less, allowing for a lower angle of attack (AOA), which in turn enables the pilot to see the ship’s deck more clearly.

However, an engineering drawback of the BLC system is that it draws thrust from the engine. Every pound of air drawn from the engine reduces the thrust expelled from the exhaust. Consequently, in the event of a ‘wave-off’, when the pilot applies full throttle, the BLC valves are programmed to close partially to prevent a loss of thrust.

A Mechanical Innovation: The Variable-Incidence Wing

Another radical solution used in naval aircraft to improve low-speed performance and pilot visibility is the ‘Variable-Incidence Wing’ system, developed by Chance-Vought and implemented in the F-8 Crusader model.

Featuring a slender, supersonic wing design, the F-8 had to raise the fuselage at a very high angle of attack (AOA) to generate the high lift required for landing. However, this meant that the long nose completely blocked the pilot’s view. Instead of tilting the fuselage, the engineers decided to rotate the wing itself relative to the fuselage.

The F-8 Crusader’s Pivot Mechanism and Operational Implications

The F-8’s wing was attached to the fuselage at a pivot point at its leading edge, and thanks to a massive hydraulic actuator, the wing’s leading edge could be raised by 7 degrees.

1. Mechanical Advantage: When the wing was raised by 7 degrees, the fuselage remained relatively horizontal whilst the wing achieved the required high angle of attack. This dramatically improved the pilot’s view of the aircraft carrier’s deck.
2. Structural Outcome: This system allowed the landing gear to be designed much shorter; as the risk of the fuselage’s tail section striking the runway during landing was reduced. Short landing gear is a factor that reduces the aircraft’s total weight.
3. Aerodynamic Challenge: However, this system had an unusual effect on the ‘Thrust Vector’. As the fuselage remained horizontal, whilst the engine thrust was operating fully horizontally, the wing was attempting to pull the aircraft upwards. This situation ‘dulled’ the aircraft’s angle of attack (AOA) response to changes in speed. Pilots frequently experienced communication issues with Landing Signal Officers (LSOs), who struggled to assess the aircraft’s energy state by observing only the fuselage angle, and this situation paved the way for numerous ‘ramp strike’ accidents.

Structural Differences Between Naval and Air Force Versions: The F-4 Phantom II Example

The process of “navalising” aircraft in the jet age constitutes a significant intervention in the aircraft’s fundamental design. The clearest example of this is the F-4 Phantom II, which was originally designed as a naval aircraft but was later adopted by the Air Force (USAF) as well.

The naval version, the F-4B, possessed the following specific structural features for aircraft carrier operations:

-Thin Wings and High-Pressure Tyres: A foldable, thin wing structure was selected to optimise hangar space. Narrow tyres—small enough to fit within these wings yet robust enough to withstand the landing impact of a 30-tonne aircraft (operating at 285 psi pressure)—were used.

-Catapult Equipment: The nose landing gear strut was fitted with a hydraulic extension mechanism capable of raising the aircraft’s nose by 20 inches at the moment of launch.

-Structural Weight: The aircraft’s airframe was significantly heavier than its Air Force counterparts to accommodate the loads from the catapult and arresting gear.

When the Air Force transitioned to the F-4C version, many of these features were altered:

F-4C Version

-Wide Tyres and Wing Bulges: As the USAF was to operate on concrete runways, it required lower-pressure, wider tyres. To accommodate these wider tyres on the wings, ‘characteristic bulges’ were created on the upper surface of the F-4C’s wings.

-Simplified Landing Gear: In the USAF version, which did not require hard landings, the Navy’s heavy and complex damping systems were simplified to save weight.

-Refuelling System: Instead of the Navy’s “probe-and-drogue” (hose-and-drogue) system, a fuel tank was added to the fuselage spine for the Air Force’s “flying boom” (flying boom) system, a fuel tank has been added to the fuselage spine.

Table 3: Technical and Structural Comparison of the F-4B (US Navy) and F-4C (USAF) Variants

Feature F-4B (US Navy) F-4C (US Air Force)

Main Tyre Type Narrow, High Pressure (285–300 psi) Wide, Low Pressure

Wing Structure Flat Upper Surface (Thin) Tyre Bulge on Upper Surface

Catapult Connection No Integrated Hook in Nose Assembly

Tail Hook (Tail Hook) Yes (to catch the cable) Yes (For use in emergencies)

Fuel Refuelling Method Telescopic Probe (Probe-and-Drogue) Fuselage Back Entry (Boom System)

Rear Cockpit Radar Intercept Officer (RIO) - Single Control (front) Weapons Systems Officer (WSO) - Dual-Pilot

The Engineering Revolution in Ship Systems: Steam Catapult and MK 7 Gear

These immense structural changes in aircraft only made sense with equivalent progress in the aircraft carrier’s own technology. Hydraulic catapults, used until the end of the Second World War, proved inadequate for launching the weight of jets. The ‘Steam Catapult’ (Steam Catapult), developed by British engineer Colin Mitchell in the early 1950s, was rapidly adopted by the US Navy, ushering in the era of supercarriers.

The Operating Principle of the Steam Catapult and Its Interaction with the Aircraft

The steam catapult (C-11 or C-13 models) utilises steam at a pressure of 600 psi or higher, drawn from the ship’s main boilers. Pistons within two massive cylinders beneath the deck are propelled forward by the steam pressure. These pistons are connected to the aircraft’s nose landing gear via a “shuttle” that exits through a channel on the deck.

At the moment of launch, the pistons generate a massive amount of kinetic energy within seconds. The “nose gear design” of carrier-based jets plays a critical role during this energy transfer. As the piston moves, a force is generated that presses the aircraft’s nose downwards (nose-down force). At the end of the launch stroke, when the shuttle comes to an abrupt halt, the aircraft’s nose strut rapidly extends (strut protrusion), which automatically raises the nose by 2 to 5 degrees, enabling the wings to immediately begin climbing. This mechanical synchronisation has been vital in overcoming the low acceleration issues of the early jet age.

MK 7 Mod 3 Arresting Gear: Energy Dissipation

The MK 7 arresting gear, which absorbs the aircraft’s kinetic energy upon ‘impact’ with the deck, is essentially a massive hydraulic brake. 36 When the aircraft’s tail hook catches the steel cable (deck pendant) on the deck, this cable moves a massive hydraulic piston (ram) beneath the deck. This piston forces the hydraulic fluid—a mixture of ethylene glycol and water—through a very narrow control valve.

The opening of this valve is manually adjusted according to the “take-off/landing weight” announced over the radio before the aircraft approaches the ship. If the valve is too tight, the aircraft comes to an abrupt halt and the fuselage may fracture; if it is too loose, the aircraft will fall into the sea from the end of the deck before coming to a stop. Modern MK 7 systems are capable of completing this energy absorption over a short distance of around 350 feet and can reset themselves within seconds for a new landing.

Future Projections: Transition to EMALS and AAG Technologies

These steam and hydraulic-based engineering solutions, developed between 1945 and 1965, have formed the backbone of naval aviation for over fifty years. However, the need to launch both heavier unmanned aerial vehicles (UAVs) and much lighter reconnaissance jets using the same system—a requirement of the 21st century—has pushed these mechanical systems to their limits.

With the introduction of the new-generation Gerald R. Ford-class aircraft carriers, steam catapults are being replaced by the ‘Electromagnetic Aircraft Launch System’ (EMALS) and hydraulic arresting gear by the ‘Advanced Arresting Gear’ (AAG).

-EMALS: Unlike steam, it provides a constant acceleration curve throughout the launch. This reduces the ‘shock loading’ stress on the aircraft’s airframe, thereby extending the aircraft’s service life.

-AAG: Using digitally controlled water turbines and induction motors, it provides damping that adapts in real time to the aircraft’s weight and speed. This eliminates the manual and coarse adjustment limitations of the MK 7.

Result: The Golden Age of Naval Aviation Engineering

Spanning from the late 1940s to the 1960s, this period represents one of the most intensive engineering transformation processes in aviation history. The transition from the simple frames of propeller-driven aircraft to ‘beasts’ such as the F-4 Phantom and F-8 Crusader—capable of reaching twice the speed of sound and taking off and landing safely every day from an impossible platform like an aircraft carrier—was made possible by revolutions in materials science, precision in hydraulic damping technologies, and genius in aerodynamic flow control.

Many structural elements now considered standard in naval aviation—such as the massive landing gear made from 300M steel, tail hooks with dashpot damping, and heavy-load-carrying beams running the length of the fuselage—are all legacies of the bitter lessons and engineering achievements of that era. This integration, which enables the aircraft and the ship to function as a single machine, formed the foundation of the US Navy’s global power projection capability and elevated the concept of ‘maritimisation’ in aeronautical engineering from a mere sub-discipline to a distinct scientific field in its own right. The transition to the jet age was not merely a change of engine, but a comprehensive reconstruction process in which the physical form of the aircraft adapted to the harsh environment of the aircraft carrier.

Our Naval Aviation series will continue.

Reading the first two articles that form the foundation of our Naval Aviation series will help you understand the technical details and doctrinal background in this article much more clearly. I have provided the link to the relevant publications below for your reference.

Take-off and Landing Configurations on Naval Aviation Platforms: CATOBAR, STOBAR and STOVL

https://strasam.org/savunma/deniz-silah-ve-sistemleri/deniz-havaciligi-platformlarinda-inis-kalkis-konfigurasyonlari-catobar-stobar-ve-stovl-4160

The Evolution of US Navy Jets from an Engine Architecture Perspective

https://strasam.org/savunma/deniz-silah-ve-sistemleri/motor-mimarisi-perspektifinden-abd-donanma-jetlerinin-evrimi-4166

References

1. Evolution of Aircraft Carriers - GovInfo, https://www.govinfo.gov/content/pkg/GOVPUB-D221-PURL-gpo67727/pdf/GOVPUB-D221-PURL-gpo67727.pdf
2. Aircraft carrier centennial: Evolution of the aircraft carrier - Navsea, https://www.navsea.navy.mil/Media/News/Article-View/Article/3089193/aircraft-carrier-centennial-evolution-of-the-aircraft-carrier/
3. Steam Catapults - Naval Marine Archive, https://navalmarinearchive.com/research/docs/steam_catapults.html
4. Hydraulics in flight-deck machinery - IMarEST, https://library.imarest.org/record/9523/files/v17b1p04a.pdf
5. RESEARCH MEMORANDUM, https://ntrs.nasa.gov/api/citations/19930090149/downloads/19930090149.pdf
6. Differences in USAF and USN jet fighters : r/WarCollege - Reddit, https://www.reddit.com/r/WarCollege/comments/1qzz0oq/differences_in_usaf_and_usn_jet_fighters/
7. McDonnell Douglas F-4 Phantom II - Wikipedia, https://en.wikipedia.org/wiki/McDonnell_Douglas_F-4_Phantom_II
8. Aircraft Load Factors and Design Loads | PDF | Aircraft | Force - Scribd, https://www.scribd.com/document/677541130/Aircraft-Loads-1-1
9. A Brief History of Tailhook Design - U.S. Navy Aircraft History, https://thanlont.blogspot.com/2011/12/brief-history-of-tailhook-design.html
10. Historical Background - Heatblur F-4E Phantom II, https://f4.manuals.heatblur.se/intro/history.html
11. Variable-incidence wing - Wikipedia, https://en.wikipedia.org/wiki/Variable-incidence_wing
12. US Navy F-8 Pilot explains why the Crusader variable incidence ..., https://theaviationgeekclub.com/us-navy-f-8-pilot-explains-why-the-crusader-variable-incidence-wing-led-to-a-ramp-strike-if-the-lso-couldnt-determine-the-f-8-energy-state/
13. Aircraft catapult - Wikipedia, https://en.wikipedia.org/wiki/Aircraft_catapult
14. How Many F-4 Phantoms Were Built? - Simple Flying, https://simpleflying.com/how-many-f-4-phantoms-built/
15. Analysis of Carrier-Based Aircraft Catapult Launching Based on Variable Topology Dynamics - MDPI, https://www.mdpi.com/2076-3417/11/19/9037
16. Milestones and Developments in U.S. Naval Carrier Aviation - Aerospace Research Central, https://arc.aiaa.org/doi/pdfplus/10.2514/6.2003-5543
17. McDonnell Aircraft/Douglas F-4B “Phantom II” | Hickory Aviation Museum, https://www.hickoryaviationmuseum.org/wp-content/uploads/2023/03/McDonnell-F-4-Phantom-II-March-1.pdf
18. Aircraft Landing Gear Design: Principles and Practices - rexresearch1, https://rexresearch1.com/AeroEngineeringLibrary/AircraftLandingGearDesignPrinciplesPractices.pdf
19. Aircraft Hydraulic System: Purpose, Components, Operation, Application, https://tsunamiair.com/airplane/hydraulics/purpose
20. Why Was 300M Steel Widely Used in Aircraft? (The Advantages of 300M Steel), https://no.baogangpipe.com/news/why-was-300m-steel-widely-used-in-aircraft-t-66430979.html
21. Why was 300M steel widely used in aircraft? (The advantages of 300M steel), https://www.shew-esteelpipe.com/news/why-300m-steel-was-widely-used-in-aircraft-t-13036743.html
22. Requirements for Ferrous-Base Aerospace Alloys - Carpenter Technology, https://www.carpentertechnology.com/blog/requirements-for-ferrous-base-aerospace-alloys
23. Corrosion Behaviour of Landing Gear Steels - DTIC, https://apps.dtic.mil/sti/tr/pdf/ADA285862.pdf
24. What is done to prevent the tail hook from bouncing off the carrier deck?, https://aviation.stackexchange.com/questions/36515/what-is-done-to-prevent-the-tail-hook-from-bouncing-off-the-carrier-deck
25. Tailhook - Wikipedia, https://en.wikipedia.org/wiki/Tailhook
26. Dashpot - Wikipedia, https://en.wikipedia.org/wiki/Dashpot
27. Dashpot Mechanism Explained: How It Works, Parts, Damping Formula, and Uses, https://www.firgelliauto.com/blogs/mechanisms/dashpot
28. Dashpot - BikeParts Wiki - Fandom, https://bikeparts.fandom.com/wiki/Dashpot
29. How Jets Stop In 2 Seconds On Aircraft Carriers - YouTube, https://www.youtube.com/watch?v=UwNYaedtCR4
30. Technical Description - Blackburn Buccaneer - Cambridge University Press & Assessment, https://www.cambridge.org/core/books/blackburn-buccaneer/technical-description/4278A51F69804FDEB2CE90709DDB912C
31. McDonnell Douglas F-4 Phantom II - The Aviation History Online Museum, http://www.aviation-history.com/mcdonnell/f4.html
32. Difference between the USAF Phantoms? : r/FighterJets - Reddit, https://www.reddit.com/r/FighterJets/comments/1lnj9zy/difference_between_the_usaf_phantoms/
33. Phantom conversion advice, F4B to F4C. - Aircraft Modern - Britmodeller.com, https://www.britmodeller.com/forums/index.php?/topic/234942462-phantom-conversion-advicef4b-to-f4c/
34. Aircraft scale models: McDonnell Douglas F-4J and USAF F-4C - Team-BHP, https://www.team-bhp.com/news/aircraft-scale-models-mcdonnell-douglas-f-4j-and-usaf-f-4c
35. Development of the steam catapult - IMarEST, https://library.imarest.org/record/9505/files/v16b3p04a.pdf
36. Mk 7 Mod 3 Aircraft Recovery Gear | PDF | Valve | Machines - Scribd, https://www.scribd.com/document/428134474/14310A-ch4-01-63
37. Mk 7 Mod 3 Aircraft Recovery Overview | PDF | Valve | Manufactured ... , https://www.scribd.com/document/406805104/14310A-ch4-pdf
38. EMALS & AAG - General Atomics, https://www.ga.com/alre
39. Advanced Arresting Gear - Wikipedia, https://en.wikipedia.org/wiki/Advanced_Arresting_Gear
40. US6758440B1 - Electromagnetic aircraft arrestor system - Google Patents, https://patents.google.com/patent/US6758440B1/en
41. Aircraft Arresting Gear (AAG) system - Neometrix Group, https://neometrixgroup.com/products/aircraft-arresting-gear-system
42. https://theaviationgeekclub.com/the-night-carrier-landing-where-a-navy-f-4-pilot-turned-in-his-wings-after-blowing-his-phantom-ii-main -landing-gear-tires-because-it-snagged-the-single-wire-mid-flight-and-impacted-the-top-of-the-third-ar/