The Douglas A-1 Skyraider, previously known as the AD before the 1962 Navy and Air Force designations unification, was an American single-seat attack aircraft that served from 1946 to the early 1980s.
It played an essential role in both the Korean War and Vietnam War, and its long career spanned the Jet Age, where most piston-engine attack or fighter aircraft had been replaced by jet aircraft.
The Skyraider was used by the United States Navy (USN), the United States Marine Corps (USMC), and the United States Air Force (USAF), and it also saw service with the British Royal Navy, the French Air Force, the Republic of Vietnam Air Force (RVNAF), and other countries.
It remained in service in the US until the early 1970s.
The Skyraider was a piston-engine, propeller-driven aircraft designed by Ed Heinemann of the Douglas Aircraft Company during World War II to meet the requirements of the United States Navy for a carrier-based, single-seat, long-range, high-performance dive/torpedo bomber.
Prototypes for the XBT2D-1 were ordered on July 6, 1944, and it made its first flight on March 18, 1945.
After evaluation by the USN at the Naval Air Test Center (NATC) in April 1945, it was designated AD-1 in December 1946 and delivered to VA-19A, the first fleet squadron.
The AD-1 was built in Southern California at Douglas’s El Segundo plant and had a low-wing monoplane design with a Wright R-3350 Duplex-Cyclone radial engine that was upgraded several times.
It had large, straight wings with seven hardpoints and was optimized for ground attack, carrying a large amount of ordnance over a considerable combat radius.
Due to its excellent manoeuvrability at low speed, it was armoured against ground fire in key locations, unlike faster fighters adapted to carry bombs, such as the Vought F4U Corsair or North American P-51 Mustang.
Its long loiter time for its size compared to much heavier subsonic or supersonic jets made it an effective close air support aircraft for the USAF and RVNAF during the Vietnam War.
Heinemann initiated a weight reduction program for the XBT2D-1 design, resulting in over 1,800 lb (820 kg) of weight reduction.
The AD series was initially painted in glossy sea blue, but the colour scheme was changed to light gull grey and white (Fed Std 595 27875) following the Korean War.
Later, the USAF began to paint its Skyraiders in a camouflaged pattern using two shades of green and one of tan.
The Skyraider went through seven versions, starting with the AD-1, then AD-2 and AD-3 with various minor improvements, and then the AD-4 with a more powerful R-3350-26WA engine.
The AD-5 was significantly widened, allowing two crew to sit side-by-side, and it also came in a four-seat night-attack version, the AD-5N.
The AD-6 was an improved AD-4B with improved low-level bombing equipment, and the final production version AD-7 was upgraded to an R-3350-26WB engine.
Skyraider production ended in 1957 with a total of 3,180 having been built.
In 1962, existing Skyraiders were redesignated A-1D through A-1J and later used by both the USAF and Navy in the Vietnam War.
It was replaced in the mid-1960s by the Grumman A-6 Intruder as the Navy’s primary medium-attack plane in supercarrier-based air wings, but Skyraiders continued to operate from smaller Essex-class aircraft carriers.
It was also modified to serve as a carrier-based airborne early warning aircraft, replacing the Grumman TBM-3W Avenger, and fulfilled this function in the USN and Royal Navy, being replaced by the Grumman E-1 Tracer and Fairey Gannet, respectively.
The A-1 was famous for being able to take hits and keep flying thanks to armour plating around the cockpit area for pilot protection. Variants XBT2D-1 Single-seat dive-bomber, torpedo-bomber prototype for the U.S. Navy. XBT2D-1N Three-seat night attack prototypes; only three aircraft built. XBT2D-1P Photographic reconnaissance prototype; only one built. XBT2D-1Q Two-seat electronic countermeasures prototype; one aircraft only. BT2D-2 (XAD-2) Upgraded attack aircraft; one prototype only. AD-1 The first production model; 242 built. AD-1Q Two-seat electronic countermeasures version of the AD-1; 35 built. AD-1U AD-1 with radar countermeasures and tow target equipment, no armament, and no water injection equipment. XAD-1W Three-seat airborne early warning prototype.
AD-3W prototype; one aircraft only. AD-2 An improved model, powered by a 2,700 hp (2,000 kW) Wright R-3350-26W engine; 156 built. AD-2D Unofficial designation for AD-2s used as remote-control aircraft, to collect and gather radioactive material in the air after nuclear tests. AD-2Q Two-seat electronic countermeasures version of the AD-2; 21 built. AD-2QU AD-2 with radar countermeasures and target towing equipment, no armament and no water injection equipment; one aircraft only. XAD-2 Similar to XBT2D-1 except for the engine, increased fuel capacity. AD-3 Stronger fuselage, improved landing gear, new canopy design; 125 built. AD-3S Anti-submarine warfare model: only two prototypes were built. AD-3N Three-seat night attack version; 15 built. AD-3Q Electronic countermeasures version, countermeasures equipment relocated for better crew comfort; 23 built. AD-3QU Target towing aircraft, but most were delivered as AD-3Qs. AD-3W Airborne early warning version; 31 built. XAD-3E AD-3W modified for ASW with Aeroproducts propeller. AD-4 Strengthened landing gear, improved radar, G-2 compass, anti-G suit provisions, four 20 mm (0.79 in) cannon, and 14 Aero rocket launchers; 372 built. AD-4B Specialized version designed to carry nuclear weapons, also armed with four 20 mm (0.79 in) cannon; 165 built plus 28 conversions. AD-4L Equipped for winter operations in Korea; 63 conversions. AD-4N (A-1D) Three-seat night attack version; 307 built. AD-4NA Designation of 100 AD-4Ns without their night-attack equipment, but fitted with four 20 mm cannon, for service in Korea as ground-attack aircraft. AD-4NL The winterized version of the AD-4N; 36 conversions. AD-4Q Two-seat electronic countermeasures version of the AD-4; 39 built. AD-4W Three-seat airborne early warning version; 168 built. A total of 50 AD-4Ws were transferred to the Royal Navy as Skyraider AEW Mk 1s. AD-5 (A-1E) Side-by-side seating for pilot and co-pilot, without dive brakes; 212 built. AD-5N (A-1G) Four-seat night attack version, with radar countermeasures; 239 built. AD-5Q (EA-1F) Four-seat electronic countermeasures version; 54 conversions. AD-5S One prototype to test magnetic anomaly detector (MAD) anti-submarine equipment. AD-5U The AD-5 when modified for target towing became the UA-1E in 1962. The same model converted as a transport was sometimes referred to as the AD-5R. AD-5W (EA-1E) Three-seat airborne early warning version with an AN/APS-20 radar installed; 218 were built. UA-1E Utility version of the AD-5. AD-6 (A-1H) Single-seat attack aircraft with three dive brakes, centreline station stressed for 3,500 lb (1,600 kg) of ordnance, 30 in (760 mm) in diameter, combination 14 in (360 mm) and 30 in (760 mm) bomb ejector and low/high altitude bomb director; 713 built. AD-7 (A-1J) The final production model, powered by an R-3350-26WB engine, with structural improvements to increase wing fatigue life; 72 built. Specifications Crew 1 Length 38 ft 10 in (11.84 m) Wingspan 50 ft 0.25 in (15.2464 m) Height 15 ft 8.25 in (4.7816 m) Wing area 400.33 sq ft (37.192 m2) Airfoil Root NACA 2417 Tip NACA 4413 Empty weight 11,968 lb (5,429 kg) Gross weight 18,106 lb (8,213 kg) Fuel capacity 380 US gal (320 imp gal; 1,400 L) internal tanks Powerplant 1 × Wright R-3350-26WA Duplex-Cyclone,
18-cylinder air-cooled radial piston engine,
2,700 hp (2,000 kW) Propellers 4-bladed Aeroproducts constant-speed propeller Performance Maximum speed 322 mph (518 km/h, 280 kn) at 18,000 ft (5,500 m) Cruise speed 198 mph (319 km/h, 172 kn) Range 1,316 mi (2,118 km, 1,144 nmi) Service ceiling 28,500 ft (8,700 m) Rate of climb 2,850 ft/min (14.5 m/s) Wing loading 46.6 lb/sq ft (228 kg/m2) Power/mass 0.149 hp/lb (0.245 kW/kg) Armament Guns 4 x 20 mm AN/M3 cannon with 200 rounds per gun Hardpoints 15 external hardpoints with a capacity of 8,000 lb (3,600 kg), with provisions to carry combinations of: Bombs, torpedoes, mine dispensers, unguided rockets, and gun pods.
Sources Douglas AD/A-1 Skyraider Part 1-Steve Ginter. Warpaint Series No. 18, Douglas Skyraider Including AD-1 to AD-7-Ken Wixley. Warbird Tech Series, Vol 13 – Douglas A-1 Skyraider- Kris Hughes & Walter Dranem. Douglas A-1 Skyraider, Osprey Air Combat, Robert F. Dorr. Douglas AD/a-1 Skyraider: Part Two-Steve Ginter. McDonnell Douglas aircraft since 1920: Volume 1-René J Francillon. San Diego Air and Space Museum Archive. The National Museum of the U.S. Air Force.
