Too late for World War II, the Douglas AD series went on to achieve a stunning combat record in both Korea and Vietnam during a career that stretched over two decades. Its story began in September 1943, when BUAER circulated the new requirement for a single-seat bomber-torpedo (BT) aircraft intended to replace SBDs, SB2Cs, and TBMs. Douglas originally submitted a proposal for the XBTD-1, which was basically a rehash of its less than successful XSB2D design; then in June 1944, the company surprised BUAER by asking for cancellation of the BTD program in favor of a totally new concept. Its proposed XBT2D-1 was much closer to BUAER’s bomber-torpedo criteria: a simple design with a tailwheel layout in which weapons were carried on external racks beneath a bottom-mounted wing. For dive-bombing, Douglas introduced a new type of dive brake system consisting of flat panels that extended from the sides and belly of the fuselage. BUAER was sufficiently interested in the new concept to award Douglas a contract for 25 pre-production BT2D-1s, and after the first prototype flew on 15 March 1945, increased the order to 548 production aircraft.
The huge government cutbacks imposed after V-J Day resulted in the BT2D contract being reduced to 277 aircraft, and when the BT designation was changed to A for attack in early 1946, the plane became the AD-1. Service trials were completed in late 1946 and by early 1947, production AD-1s began replacing SB2Cs and TBMs in fleet units. The final 25 aircraft were delivered as AD-1Qs, a specialized ECM sub-variant that featured a separate compartment aft of the pilot for a radar operator. When the AD-1 had been in service less than a year, BUAER selected it as the Fleet’s standard single-seat attack type and made plans to acquire improved versions. Deliveries of 152 AD-2s having the more powerful R-3350-26W engine, stronger wings, a new canopy design, and fully enclosed wheel covers began in mid-1948 and were joined by an additional 21 AD-2Qs and one AD-2QU target tug. During 1948-1949 the Navy took delivery of 127 AD-3s possessing even more airframe strengthening, longer stroke landing gear, and a redesigned tailwheel, plus 15 three-seat night attack AD-3Ns, 31 three-seat early-warning AD-3Ws fitted with belly radomes, and 21 two-seat AD-3Qs.
The AD-4, introduced in 1949 with increased takeoff weight, a stronger tailhook, and a P-1 autopilot, also came in night attack, early-warning, and ECM sub-variants.
BUAER originally anticipated AD production would end in 1950 when the last of 180 AD- 4 variants were delivered, but naval involvement in the Korean War, which began in June 1950, had the unexpected effect of continuing AD production nonstop and led to demand for development of new versions. By the end of 1952, 1,051 AD-4s (all variants) had been delivered, and they were followed by 165 AD-4Bs armed with four 20-mm cannons and also configured to carry a tactical nuclear weapon, the first single-seat naval aircraft to have such capability.
Originally envisaged as a four-seat ASW platform, the AD-5 emerged with a fuselage lengthened by two feet and widened to permit side-by-side seating for a pilot and three crewmembers under an elongated canopy. Fin area was increased and the dive-brakes on the sides of the fuselage were deleted. But even before the first AD-5 flew in August 1951, BUAER changed its mind and earmarked it for production as an attack aircraft. The 212 standard attack versions subsequently built came with conversion kits, which, in addition to its basic attack function, allowed the type to be used either as a transport (12 seats), cargo carrier, ambulance, or target tug. Production AD-5s began entering service in late 1953 and were followed by 218 AD-5W early-warning and 239 AD-5N night/all-weather attack sub-variants, 54 of which were later modified as AD-5Q ECM aircraft.
The refinements of the AD-4B, plus LABS (low-altitude bombing system), new bomb racks, a jettisonable canopy, and a hydraulic tailhook were standardized in the single-seat AD- 6, which flew in 1953 and replaced AD-4s during 1954-1956. After delivery of 713 AD-6s, the final model was the single-seat AD-7, which differed in having a more powerful R-3350-26WB engine, stronger landing gear, and stronger outer wing panels. AD production finally ended in February 1957 when the last of 72 AD-7s rolled off El Segundo’s assembly line.
ADs were destined to remain in active naval service for 22 years-considerably longer than BUAER expected. In late 1946-early 1947, VA-19A, VA-3B, and VA-4B were the first squadrons to receive ADs, and by the eve of the Korean war, the type was equipping sixteen Navy and two Marine attack squadrons. In Korea, ADs operating from both carriers and land bases earned a reputation as the best all-around attack aircraft in the combat zone. Besides flying day attack, night attack, countermeasures, and early-warning missions, it was the only aircraft in the theater capable of delivering 2,000-lb. bombs against hardened targets (like bridges and dams) with dive-bomber precision. After Korea, AD’s carried on as naval aviation’s standard single-seat attack type and reached their peak in the mid-1950s when they equipped 29 Navy and 13 Marine squadrons. Even though a gradual phase-out of the type began in 1956 with the arrival of A4Ds, BUAER still planned to keep its ADs in service until the early 1960s. Moving somewhat faster, the Marine Corps retired its last AD-6 at the end of 1959.
When the tri-service system was adopted in September 1962, those ADs remaining in service were re-designated as follows: AD-5=A-1E; AD-5W= EA-1E; AD-5Q=EA-1E; AD- 5N=A-1G; AD-6=A-1H; and AD-7=A-1J. In 1964, plans to retire the type were postponed by military developments in Southeast Asia, where A-1s subsequently flew hundreds of combat sorties as part of the ongoing carrier task force stationed off the coast of Vietnam. Owing to their slower speed and excellent loiter range, A-1s were considered the best tactical aircraft available for escorting troop-laden helicopters and ground-fire suppression in rescue combat air patrol (RESCAP) operations. Though never intended for air-to-air confrontations, Navy A- 1Hs were in fact credited with the downing of North Vietnamese MiG-17s on two occasions. The type’s active naval career ended in 1968 when the last single-seat combat sortie was flown by an A-1H of VA-25 in February and the final ECM mission by an EA-1E of VAQ-33 in December.
In the early 1960s, as U. S. military involvement in Southeast Asia increased, the USAF found itself without any type of attack aircraft that could be adapted to slow, close-in operations like counter-insurgency (i. e., COIN: suppression and interdiction of guerilla troops and supplies) or RESCAP. Several different types of aircraft, all prop-driven, were evaluated at the Special Warfare Center located at Eglin AFB in Florida, including several ex-Navy A-1 Skyraiders. Once the tests were concluded, USAF officials immediately made plans to acquire 150 surplus wide-body A-1Es from Navy stocks to be overhauled for expected service in Vietnam. Modifications included addition of dual controls and weapons racks not normally carried on Navy E models. Actual combat operations commenced in early 1964 with the 34th Tactical Group based at Ben Hoa AB in South Vietnam. A-1E sorties were initially flown with a Vietnamese observer in the right seat for the purpose of target identification, but for most of its service the type was flown as a single-pilot attack aircraft. As they became available from Navy stocks in the mid and late 1960s, the USAF also began to operate single-seat A-1Hs and Js which became especially well-known for their “Sandy” operations-RESCAPs escorting the “Jolly Greens” (i. e., Sikorsky HH-53 helicopters) deep into North Vietnamese or Laotian airspace to rescue downed American pilots and aircrew. The USAF operated A-1s on Sandy missions up until November 7, 1972, when American involvement in Vietnam was almost at an end.
Skyraiders were probably the most numerically important aircraft to operate with the Air Force of the Republic of Vietnam (VNAF). In fact, the American government began the transfer of surplus Navy AD-6s (A-1Hs) to the VNAF in 1960, and as they became available, more followed. VNAF Skyraider pilots were initially trained by the Navy at NAS Corpus Christi and later by the Air Force at Hurlburt AFB. During the so-called “Vietnamization” of the war between 1969-1972, many Air Force A-1s were simply turned over to the VNAF when U. S. forces left the country. During this time the VNAF reached a peak strength of eight Skyraider squadrons, and they were operated in combat all the way up to the fall of Saigon in April 1975. Although a number of VNAF A-1s are known to have fallen into North Vietnamese hands, no apparent effort was made to put them back into service. Beginning in 1951, the British Royal Navy Fleet Air Arm (FAA) began taking delivery of AD-4Ws for use aboard its carriers in the airborne early-warning role. The first 20 aircraft were new, but the remaining 30 of 50 delivered were supplied from U. S. Navy stocks. Known as the Skyraider AEW. 1, the type remained in frontline service with the FAA until replaced by Fairey Gannets in 1962. A number of these aircraft were thereafter converted to target tugs and operated by the Swedish Air Force until the early 1970s. Forty surplus AD-4s were sold to the French Air Force in 1959 and thereafter flew combat in support of French forces in Algeria and Chad (1960) and in French Somaliland and Madagascar (1963). French Skyraiders remained in service in small numbers until the early 1970s, and some of these were turned over to the Cambodian Air Force, where they were briefly used against Viet Cong and North Vietnamese troops.
Korean War Skyraiders
By 1950, the TBM Avenger torpedo-bomber, SB2C Helldiver dive-bomber and the post-war AM Mauler had been replaced on fleet carriers by a new type in the form of the single-seat Douglas AD (formerly BT2D) Skyraider attack aircraft. A rugged, powerful aeroplane capable of carrying a 10,000-lb ordnance load of bombs, rockets and torpedoes, as well as 20 mm cannon, the AD, or `Able Dog’, as it was often called, prevailed over several competing designs and sidelined the similar AM Mauler to become the standard attack aircraft in the fleet.
More than 865 ADs had been built in four basic versions by the time hostilities broke out in Korea, including a wide range of specialised variants. The AD-1, a production version of the XBT2D-1 prototype, had been superseded by later versions by the time the conflict commenced in June 1950, and none of the 242 built saw combat. The AD-2, of which 156 were built, featuring greater structural strength, greater internal fuel capacity and a revised cockpit, saw extensive combat, however. The 125 AD-3 versions, which featured still more strengthening, a redesigned canopy, improved cooling of the engine and improved landing gear, also helped to equip US Navy attack (VA) squadrons during war deployments to Korea.
The AD-4 version and its sub-variants – the production standard in 1950 – were the most numerous to serve in the Korean War, equipping attack squadrons in 17 of the 25 combat deployments undertaken by Skyraider units. The AD-4 featured an uprated engine, an improved cockpit windscreen, a modified tailhook and a P-1 autopilot. Production totalled 372 examples, of which 63 were modified specifically for service in the harsh Korean winters. Designated AD-4Ls, they boasted anti-icing equipment and de-icer boots on the leading edges of the wings. The AD-4Ls were also fitted with an additional two cannon. When the `Able Dog’ was assigned the role of nuclear strike, 28 AD-4s were structurally strengthened for loft-bombing and designated AD-4Bs. An additional 165 AD-4Bs were built as such at the factory. One attack squadron and one composite (VC) squadron deployed to the Korean war zone with the AD-4B.
The versatility of the TBM was carried over into the AD, as the Skyraider was modified to perform a variety of specialised missions. The aft fuselage of an XBT2D-1 was converted to accommodate an electronic countermeasures (ECM) operator crew station and an access door to produce an XBT2D-1Q prototype. This change was made operational with the creation of 35 AD-1Qs. The modification followed with the production of 21 AD-2Qs, 23 AD-3Qs and 39 AD-4Qs. The AD-2Q, AD-3Q and AD-4Q saw combat over Korea with several attack and fighter AD units, plus VCs -33 and -35. Early Q-models had only an electronic surveillance measures capability, with ECM – jamming – coming later.
Similar in configuration to the Q versions were the night-attack variants, the AD-3N and AD-4N. Unlike the Q, the N featured two crew stations – one for a radar operator – in the aft fuselage, along with two access doors, but left no room for dive brakes. The AD-3N carried the APS-19A radar pod, while AD-4Ns were equipped with wing-mounted APS-31 radar and a searchlight. They also boasted an electronic surveillance measures (ESM) capability similar to the Q. Production of the AD-3N totalled only 15 aircraft, and the type saw combat on just two Korea deployments with VC-3 and VC-35. The AD-4N was much more abundant, with 307 built, of which 37 were modified with the AD-4L’s cold-weather upgrades and extra 20 mm cannon. These became AD-4NLs. Because of the increased demand for straight attack aircraft in Korea, 100 AD-4Ns were stripped of their two aft crew stations, fitted with the extra cannon and given the designation AD-4NA.
Succeeding the TBM-3W in the airborne early warning role were the unarmed AD-3W and AD-4W Skyraiders, modified with a similar belly radome housing an APS-20 search radar. The radar was operated by two crewmen housed in the aft fuselage under a turtleback extension of the cockpit. The W variants were primarily used to warn carrier battle groups of approaching aircraft, although they also performed the anti-submarine search role. The US Navy procured 31 AD-3Ws and 118 AD-4Ws.
The US Navy’s carrier force in June 1950 included only nine carrier air groups (CVGs), just three of which were based in the Pacific. This was principally because the Cold War was in full swing and support of the North Atlantic Treaty Organisation facing the Soviet Union in Europe was the top priority for US naval forces in early 1950. The US Navy had nine AD attack squadrons in service at the outbreak of the Korean War, one per carrier air wing.
By the end of the Korean War, the US Navy fielded 16 attack and two frontline fighter squadrons equipped with Ads.
Attack squadrons would initially deploy with a single attack version of the AD, but as the war progressed and attrition occurred other models were sent as replacement aircraft. Some VA squadrons flew AD-2/3/4/4Q versions during a single deployment, and AD-4L/NL/NAs entered the mix later in the war. When a carrier departed station for home, it would transfer some aeroplanes to other carriers or to the aircraft replacement pool at Atsugi, Japan. Some AD attack squadrons (typically equipped with 18 aircraft of all types) also included a few Q-models in their line-up. In addition, special mission composite squadrons (VC) for night attack, ESM/ECM and early warning included VC-3, VC-11 and VC-35 in the Pacific Fleet and VC-4, VC-12 and VC-33 in the Atlantic Fleet.
During this period, CVG staffs were also occasionally equipped with one or two ADs, usually including the Q versions. For administrative efficiency, the CVG staff and VC dets were organised into temporary squadrons, with the senior officer of the various VC detachments as the `commanding officer’. Although discontinued in June 1949, the practice of giving these temporary units a designation continued unofficially in some cases. `VC-110′ was such a unit in CVG-11, for example. For the purposes of this book, the dets will be discussed in terms of their parent units.
The numerous Naval Air Reserve Training Units had yet to receive any Skyraiders by June 1950, being equipped instead with AM-1s and TBMs.
Also of note, at the beginning of the Korean War the US Marine Corps did not field any attack squadrons (VMA), nor was it equipped with any Skyraiders. It relied instead on F4U-4/5/5N variants of the Corsair and on nightfighter versions of the F7F Tigercat. Although the Marine Corps was slated to begin receiving W- and Q-models of the AD in 1950, its Skyraiders did not reach Korea until mid-1951.
The units that flew Skyraiders in both the USAF and the Vietnamese Air Force (VNAF) during the Vietnam War. The 12 squadrons of these two air forces that were equipped with the Douglas aircraft saw extensive combat from 1960 to 1975. And this 15-year period is but five years short of spanning the entire existence of the VNAF. History will show that with the introduction of the AD-6 Skyraider in 1960, the VNAF truly had a capable, albeit demanding, aircraft – demanding in that it required a pilot’s full attention all of the time, whether in the air or on the ground. That it lasted 15 years as the VNAF’s frontline attack aircraft speaks volumes for its capabilities, and those of the men who flew it.
These capabilities, however, did not come without a price. Of the approximately 350 Skyraiders operated by the VNAF, only 70 remained by the end of 1973. And by the time the North Vietnamese Army (NVA) invaded South Vietnam in April 1975, just 40 Skyraiders were left at various VNAF bases for the enemy to use as they saw fit. It was the end of not only the VNAF, but also of the country the Skyraider units had fought so hard to defend.
Nestled inside this 15-year timeframe was the eight-year period that the USAF operated various models of the A-1 Skyraider in Southeast Asia. Commencing operations in-theatre in mid-1964, Skyraiders were the premier close air support (CAS) aircraft for the USAF until the end of 1972. The A-1 also became synonymous with the search and rescue (SAR) mission, and many a downed airman gave thanks when he heard the voice of a `Sandy’ on his survival radio, followed shortly after by the din of the Wright R-3350 radial engine as the Skyraider roared overhead. But make no mistake, the A-1 served well in all of its roles, from Special Forces fort defence to Military Assistance Command, Vietnam – Studies and Observations Group (MACV-SOG) support.
All Skyraider pilots gave some, but far too many gave their all. Of the approximately 330 A-1s operated by the USAF in Southeast Asia, nearly 200 were lost. More than 100 USAF Skyraider pilots were either killed in action or listed as missing in action.