In the beginning of the 1950’s the US Navy began to look for a replacement of the AD Skyraider attack aircraft. Such aircraft would have to be capable of carrying 2000 pounds/907 kg payload (default – a nuclear bomb), at range of 300 naval miles (557 km), with a maximum speed of 500 knots (928 km/h) and have a maximum take-off weight of 30 000 pounds (13 608 kg). The Douglas company started to work on an aircraft like specified in the January of 1952 and the company’s chief engineer, Ed Heinemann decided to use proven design features together with the jet propulsion. The US Navy then refined their specifications to look like follows: The new aircraft’s empty weight was not to exceed 8 136 pounds (3 690 kg) and the takeoff weight 15 000 pounds (27 825 kg), including twice the bomb load of the previous specification, and the range was to be 100 miles (160 km) bigger than before. The Douglas company went on to work on the new aircraft and on the 21st of June 1952 it signed the contract to deliver two prototypes of aircraft designated XA4D-1. In September the US Navy got so confident in the success of the new aircraft, that the contract was increased to 19 pre-series machines not waiting on the flight tests of the prototypes.
The prototype of the XA4D-1 was ready on 6th of June 1954 and it was called “Skyhawk” – in line with the names of previous Douglas designs for the US Navy (such as Skyraider, Skyknight and Skywarrior). Even before that the new aircraft was known as “Heinemann’s Hot Rod”. The first flight of the prototype was conducted on June 22nd, 1954 in the Edwards Air Force Base, in the Mojave desert. It was the beginning of a long and intensive program of flight tests of the new design. Test carrier landings started on the 13th of September, 1955. In October 1955 the first production-type A4D-1s were delivered to VA-72 stationed in Quonset Point, Rhode Island where pilots were training on the new type of aircraft.
Even before the first A4D-1s reached the units, the work started to develop the improved variant designated A4D-2. The changes included the addition of in-flight refueling gear, strengthening the landing gear and improving the air to surface armament systems. All A4D-2s had the “inside out” rudders (with reinforcement ribs visible on the outside), they were also capable of carrying the “buddy pack” – a device enabling them to serve as airborne tankers. The A4D-2 first flew on 26th of March 1956. Their delivery to the units started in September 1957. There were 165 A4D-1s and 542 A4D-2s produced.
The Skyhawk was a very compact and thought-out design, with a focus to reduce the mass and complexity of the aircraft. First of all the wing span was adjusted to the width of the aircraft carrier elevator, which allowed to omit the wing fold mechanism. The design of the wings was further simplified by giving up full landing gear retraction – it’s struts don’t penetrate the main spar of the wing, they are only stored in the fairings on the wing’s lower surface – that makes the spar simpler and lighter. Also the way the landing gear retracts (forward and up) allows to omit the emergency extension equipment – gravity and ram air does it instead. Likewise the slats that extend automatically save weight and make the design simpler.
In 1962 the designation system of American military aircraft was changed and in the new system A4D-1s were designated A-4A, and the A4D-2s – A-4B.
At the beginning of the Vietnam War, in 1964, the A-4Bs were already obsolete. There were new versions available and the A-4B wasn’t capable of conducting its mission at night or in bad weather. In spite of these deficiencies many of those aircraft made it to Vietnam early in the war. The model in the photos above depicts an A-4B in the colors of the VA-15 “VALions”. This unit sailed in 1965 from the Mediterranean, through the Indian Ocean and from April to November 1966 took part in the Vietnam War. It conducted 2 627 combat sorties with 4 777 hours cumulative duration, mostly over North Vietnam.
|Length :||12 002 mm|
|Height:||4 560 mm|
|Wing span:||8 382 mm|
|Empty weight:||4 152 kg|
|Maximum takeoff weight:||10 206 kg|
|Propulsion:||One Curtiss-Wright J65-W-16A jet engine, 34 250 N thrust|
|Armament:||Two Colt Mk12 calibre 20mm machine cannons with 100 rounds of ammo per cannon; The A-4B could in addition carry 3587 kg of ordnance (bombs and rockets) externally, on 2 stations under wings and 1 under the fuselage|
|Range:||3 000 km (depending on configuration, flight profile, weapon loadout etc.)|
|Max speed:||1 064 km/h|