The Douglas A-4 Skyhawk is a carrier-capable ground-attack aircraft designed for the United States Navy and U.S. Marine Corps. The delta winged "Skyhawk", powered by a single turbojet was designed and produced by Douglas Aircraft Company (later McDonnell Douglas). The "Skyhawk" was originally designated the A4D under the US Navy's pre-1962 designation system.
The Skyhawk was designed by Douglas Aircraft's Ed Heinemann in response to a U.S. Navy call for a jet-powered attack aircraft to replace the older A-1 Skyraider. Heinemann opted for a design that would minimize its size, weight, and complexity. The result was an aircraft that weighed only half of the Navy's weight specification. It had a wing so compact that it did not need to be folded for carrier stowage. The diminutive Skyhawk soon received the nicknames "Scooter", "Kiddiecar", "Bantam Bomber", "Tinker Toy Bomber", and, on account of its nimble performance, "Heinemann's Hot-Rod".
The aircraft is of conventional post-World War II design, with a low-mounted delta wing, tricycle undercarriage, and a single turbojet engine in the rear fuselage, with two air intakes on the fuselage sides. The tail is of cruciform design, with the horizontal stabilizer mounted above the fuselage. Armament consisted of two 20 mm Colt Mk 12 cannon, one in each wing root, with 200 rounds per gun, plus a large variety of bombs, rockets, and missiles carried on a hardpoint under the fuselage centerline and hardpoints under each wing (originally one per wing, later two).
The design of the A-4 is a good example of the virtues of simplicity. The choice of a delta wing, for example, combined speed and maneuverability with a large fuel capacity and small overall size, thus not requiring folding wings, albeit at the expense of cruising efficiency. The leading edge slats are designed to drop automatically at the appropriate speed by gravity and air pressure, saving weight and space by omitting actuation motors and switches. Similarly the main undercarriage did not penetrate the main wing spar, designed so that when retracted only the wheel itself was inside the wing and the undercarriage struts were housed in a fairing below the wing. The wing structure itself could be lighter with the same overall strength and the absence of a wing folding mechanism further reduced weight. This is the opposite of what can often happen in aircraft design where a small weight increase in one area leads to a compounding increase in weight in other areas to compensate, leading to the need for more powerful, heavier engines and so on in a vicious cycle.
The A-4 pioneered the concept of "buddy" air-to-air refueling. This allows the aircraft to supply others of the same type, eliminating the need of dedicated tanker aircraft— a particular advantage for small air arms or when operating in remote locations. A designated supply A-4 would mount a center-mounted "buddy store", a large external fuel tank with a hose reel in the aft section and an extensible drogue refueling bucket. This aircraft was fueled up without armament and launched first. Attack aircraft would be armed to the maximum and given as much fuel as was allowable by maximum take-off weight limits, far less than a full tank. Once airborne, they would then proceed to top-off their fuel tanks from the tanker using the A-4's fixed re-fueling probe on the starboard side of the aircraft nose. They could then sortie with both full armament and fuel loads.
The A-4 was also designed to be able to make an emergency landing, in the event of a hydraulic failure, on the two drop tanks nearly always carried by these aircraft. Such landings resulted in only minor damage to the nose of the aircraft which could be repaired in less than an hour. Ed Heinemann is credited with having a large "K.I.S.S." sign put up on the wall of the drawing office when the aircraft was being designed. Whether this is true, the A-4 certainly is a shining example of the application of that principle to aircraft design.
The Navy issued a contract for the type on 12 June 1952, and the first prototype first flew from Edwards Air Force Base, California on 22 June 1954. Deliveries to Navy and U.S. Marine Corps squadrons (to VA-72 and VMA-224 respectively) commenced in late 1956.The Skyhawk remained in production until 1979, with a total of 2,960 aircraft built, including 555 two-seat trainers..
he A-4 Skyhawk was introduced to a training role in the two-seat TA-4J configuration replacing the TF-9J Cougar as the advanced jet trainer The TA-4J served as the advanced jet trainer in white and orange markings for decades until being replaced by the T-45 Goshawk. Additional TA-4J Skyhawks were assigned to Instrument Training RAGs at all the Navy "master jet bases" under RCVW-12 and RCVW-4. The Instrument RAGs initially provided jet transition training for Naval Aviators during the time period when Naval Aviation still had a great number of propeller-driven aircraft and also provided annual instrument training and check rides for Naval Aviators. The assigned TA-4J models were installed with collapsible hoods so the aviator under training had to demonstrate instrument flying skills without any outside reference. These units were VF-126 at NAS Miramar, VA-127 (later VFA-127) at NAS Lemoore, VF-43 at NAS Oceana and VA-45 (later VF-45) at NAS Key West.
Additional single-seat A-4 Skyhawks were also assigned to composite squadrons (VC) worldwide to provide training and other services to deployed units. These included VC-1 at NAS Barber's Point, VC-7 at NAS Miramar, VC-5 at NAS Cubi Point, the Philippines, VC-8 at NAS Roosevelt Roads, Puerto Rico, VC-10 at Guantánamo Bay NB, Cuba, VC-12 (later VFC-12) at NAS Oceana and VC-13 at NAS Miramar.
With renewed emphasis on Air Combat Maneuvering (ACM) training brought on with the establishment of the Navy Fighter Weapons School (TOPGUN) in 1968, the availability of A-4 Skyhawks in both the Instrument RAGs and Composite Squadrons at the "master jet bases" presented a ready resource of the nimble Skyhawks that had become the TOPGUN preferred surrogate for the MiG-17. At the time, the F-4 Phantom was just being exploited to its full potential as a fighter and had not performed as well as expected against the smaller North Vietnamese MiG-17 and MiG-21 opponents. TOPGUN introduced the notion of dissimilar air combat training (DACT) using the A-4E in the stripped "Mongoose" configuration with fixed slats.
The small size of the Skyhawk and superb low speed handling in the hands of a well trained aviator made it ideal to teach fleet aviators the finer points of DACT. The squadrons eventually began to display vivid threat type paint schemes signifying their transition into the primary role of Adversary training. To better perform the Adversary role, single-seat A-4E and F models were introduced into the role, but the ultimate adversary Skyhawk was the "Super Fox," which was equipped with the uprated J52-P-408 engine similar to the configuration used by the Blue Angels.
The surplus of former USMC Skyhawks resulted in A-4M versions being used by both VF-126 and TOPGUN. Even though the A-4 was augmented by the F-5E, F-21 (Kfir), F-16, and F/A-18 in the Adversary role, the A-4 remained a viable threat surrogate until it was retired by VF-43 in 1993 and shortly thereafter by VFC-12. The last A-4 fleet operators were VC-8, which retired its Skyhawks in 2003.
General characteristics: Crew: 1 (2 in TA-4J, TA-4F, OA-4F), Length: 40 ft 3 in (12.22 m) Wingspan: 26 ft 6 in (8.38 m), Height: 15 ft (4.57 m), Wing area: 259 ft² (24.15 m²), Airfoil: NACA 0008-1.1-25 root, NACA 0005-0.825-50 tip, Empty weight: 10,450 lb (4,750 kg), Loaded weight: 18,300 lb (8,318 kg), Max takeoff weight: 24,500 lb (11,136 kg), Powerplant: 1× Pratt & Whitney J52-P8A turbojet, 9,300 lbf (10,000+ USMC A-4M and OA-4M) (41 kN)
Performance: Maximum speed: 585 knots (673 mph, 1,077 km/h), Range: 1,700 nm (2,000 mi, 3,220 km), Service ceiling 42,250 ft (12,880 m), Rate of climb: 8,440 ft/min (43 m/s), Wing loading: 70.7 lb/ft² (344.4 kg/m²), Thrust/weight: 0.51, g-limit: -3/+8 g. Armament:
Guns: 2× 20 mm (0.787 in) Colt Mk 12 cannon, 100 rounds/gun, Missiles: 4× AIM-9 Sidewinder, AGM-45 Shrike ARM (anti-radiation missile), AGM-65 Maverick ASM (air-to-surface missiles), AGM-62 Walleye glide bomb, AGM-12 Bullpup ASM (air-to-surface missiles), Bombs: 9,900 lb (4,490 kg) on five external hardpoints, Rockeye Mk.20 Cluster Bomb Unit, Rockeye Mk.7/APAM-59 Cluster Bomb Unit, Mk.81 (250 lb) and Mk.82 (500 lb) general-purpose bombs, various tactical nuclear missiles and bombs, Mk.76 practice bombs
USN 09 René Hieronymus Scale 1:72 Building time: 19 hrs