The Douglas Skyraider was designed in the last days of World War II to meet the requirements for a carrier-based dive/torpedo bomber to succeed such airplanes as Curtis Helldiver or Grumman Avenger. The prototype of the new machine, constructed by the famed Ed Heinemann was ordered on the 6th of June 1944 under the designation XBT2D-1. It's first flight was conducted on 18th of March 1945 and in April of the same year the US Navy begun to test the new design. In December 1946 the tests were finished and the new aircraft went into production under the designation AD-1.
AD Skyraider was the main attack aircraft of the US Navy after World War II, and was modified many times (versions from AD-1 to AD-7), it could also carry almost every external weapon in the US inventory, including torpedoes and even nuclear bombs. There was also the AD-5 variant, in which two pilots sat side-by-side, and the fuselage had enough room for cargo, ten passengers or four stretcher patients.
During the Korean War the Skyraiders performed their duties very well, serving the US Navy and the Marines.
In 1962 the designations of all types of aircraft used by US Navy were changed to become part of the United States Tri-Service aircraft designation system. From that moment on all variants of the AD family changed their designations to A-1. Main variants of the Skyraider are shown in the table below:
| Old designation | New designation | Description |
| AD-1 | First variant of the aircraft | |
| AD-1Q | Electronic Counter-Measures (ECM) variant. The so-called "Q-bird". Additional electronic equipment and a place for an additional crew member in the rear fuselage | |
| AD-2 | Corrected and strengthened variant | |
| AD-2Q | ECM variant, similar to AD-1Q | |
| AD-2QU | Target towing variant, one AD-2Q (122373) aircraft was modified | |
| AD-3 | Further improvements, slightly corrected undercarriage, exhaust and propeller | |
| AD-3Q | ECM variant, improved on AD-2Q | |
| AD-3W | Early warning version, with radar in a large radome under the fuselage and place for two additional crew members in the fuselage | |
| AD-3E | Special electronic equipment variant, two AD-3W aircraft were modified | |
| AD-3N | Night attack variant, with crew of three | |
| AD-3S | Anti-submarine variant, two AD-3N were modified | |
| AD-4 | New attack variant, with altered electronic equipment, improved canopy and armament increased from two to four 20mm cannons | |
| AD-4L | Winterized attack variant, equipped with de-icing gear | |
| AD-4B | Nuclear weapons capable variant | |
| AD-4Q | ECM variant | |
| AD-4N | Night attack variant | |
| AD-4NL | Winterized night attack variant | |
| AD-4NA | A-4D | Day attack variant, resulted from removal of additional equipment from AD-4N aircraft for use in Korean War |
| AD-4W | Early warning variant, with radar under the fuselage | |
| AD-5 | A-1E | Attack variant, extensively modified in comparison to previous variants, with two-man crew sitting side-by-side, widened and lengthened fuselage and enlarged vertical stabilizer |
| AD-5U | UA-1E | AD-5/A-1E aircraft assigned for utility duties and towing practice targets |
| AD-5N | A-1G | Night attack variant |
| AD-5Q | EA-1F | ECM variant. Due to modular structure, this variant was very versatile, also known as "12 in 1" |
| AD-5W | EA-1E | Early warning variant, with radar under the fuselage |
| AD-5S | Anti-submarine variant, one prototype was built | |
| AD-6 | A-1H | Single-seated attack variant, development of the nuclear-capable AD-4B. Variant in production parallel to the AD-5 |
| AD-7 | A-1J | Further development of the AD-6, with strengthened motor and landing gear |
As the war in Vietnam begun, the Skyraider was actually obsolete, the future belonging to jet-powered aircraft. Nevertheless the Skyraiders of the US Navy (also called Able Dogs from the old AD designation) conducted strike missions, for which they were designed, over both South and North Vietnam. When the US Navy begun to withdraw the Skyraiders and replace them with the Douglas A-4 Skyhawk, the US Air Force expressed its interest in the older machine. Initially it was meant to provide the air force of Republic of Vietnam (VNAF) with a close support aircraft with the capability to carry a crew of two, the Vietnamese pilot and the American "Advisor". The availability of "wide face" double-seated Skyraiders gave an opportunity to use those cheap and simple to maintain machines, which were at the same time very effective against lightly armed opponent. Later the USAF also adopted the single-seated variant.
The USAF introduced several significant modifications in its airplanes after acquiring them from the Navy. The most important was the installation of the ejection seat with a tractor rocket, also known as the "Yankee seat" enabling the pilot to bail out at low speed, low altitude and unusual aircraft stance. Additionally the tail wheel got bigger with a pneumatic tire, landing lights were added as well as additional radios for communication with the troops on the ground. After some time the cast main landing gear wheels were usually exchanged to stamped sheet metal ones, due to problems with cracking of the cast wheels.
A special variant of the close air support mission was the search and rescue mission, in which the Skyraider was to escort the rescue helicopters in their effort to extract the shot down airmen. In such a mission, the Skyraiders, callsign "Sandy", were unequalled by other aircraft. Sandys, sometimes also called "SPAD" (from a popular WWI fighter type), were able to fly slowly to improve the accuracy and also were able to stay on target longer than any comparable jet aircraft of that time, and with a huge weapon load which allowed for long work over the site where the downed airman was.
After the Skyraider was withdrawn from service, which happened directly after withdrawal of the American forces from Vietnam in 1972, for a long time there was no aircraft capable of replacing it. Just after the USAF introduced the A-10 Thunderbolt II in it's inventory it regained the "low and slow" capability.
| Length : | 11 938 mm |
| Height: | 4775 mm |
| Wing span: | 15 240 mm |
| Empty weight: | 5 400 kg |
| Maximum takeoff weight: | 8 213 kg |
| Propulsion: | One 1986 kW (2700 HP) Wright R-3350-26WB 18-cylinder air-cooled radial engine |
| Armament: | Four 20mm M3 cannons in the wings; The Skyraider could in addition carry 3629 kg of ordnance (bombs, rockets, cannon pods) externally, on 15 stations under wings and fuselage |
| Range: | 2116 km |
| Max speed: | 518 km/h |
| Crew: | 1 pilot |
