Authored By Dan Alex (Updated: 3/20/2016):
Douglas had attempted to sell the USN on several "large" carrier-based aircraft designs in an effort to keep USN interest in Douglas aircraft products for as long as could be had. However, many projects became stillborn or forgotten ventures so an all-new approach was taken with the next attempt. The initiative was born through talks with USN authorities in June of 1944 and veteran Douglas engineers (including famous aircraft designer Ed Heinemann) immediately went to work, producing a large fighter concept in short order. The presented proposal from Douglas was enough to win over the USN and order for fifteen (later increased to twenty-five) prototypes under the "XBT2D-1" designation was handed down on July 21st.
The speed at which the war evolved also dictated development windows of wartime aircraft ventures and the XBT2D-1 proved no different. The design team had the mockup completed in August for review and a premium was placed on expediency so many existing components and proven design elements were incorporated into the new aircraft. Much thought was also given to the design based on first-hand accounts from pilots in the field and company personnel bringing these notes back stateside. The prototype was unveiled in February of 1945 and the aircraft flown for the first time on March 15th of that year - the XBT2D-1 coming in both under weight and some four months ahead of the intended development schedule.
The XBT2D-1 appeared as if an oversized fighter and was, on the whole, a most conventional looking aircraft for the time. Engineers did away with the idea of an internal bomb load to open space for fuel and other applicable equipment. Ordnance carrying capability came from the straight wing appendages which provided for seven hardpoints each. Additionally there lay a single hardpoint under the fuselage. At least two underwing positions and the fuselage centerline hardpoint were also plumbed for external fuel stores while internal fuel all resided in a single tank. A powerful Wright R-3350-8 supercharged radial piston engine of 2,300 horsepower was fitted in the nose and this drove a large four-blade propeller unit. Immediately aft of the engine compartment lay the single-seat cockpit under a bubble canopy offering elevated views over the nose and wings. As the aircraft was expected to fly in low against enemy air defenses the cockpit was protected with over 200 lb of armor plating. The wings were fixed ahead of amidships bringing most of the aircraft's mass forward. The fuselage was largely tubular in shape though somewhat deep (and awkward looking) in profile. The lower rear fuselage sides were slab-sided and contained dive brake panels with a third panel added to the belly. The tail unit utilized a rounded vertical fin and low-set horizontal planes. A typical "tail-dragger" undercarriage arrangement was used with the main legs retracting rearwards under the wings. An arrestor hook was fitted under the tail and the wing mainplanes were designed to fold outboard of the main legs for carrier storage.
The fifteen total hardpoints - coupled with the massive engine output - allowed for up to 6,000 lb of external stores to be carried. Standard armament included 2 x 20mm cannons (later four) installed in the wings. These weapons could be used as both an offensive and defensive measure by the pilot (as seen in the wars to follow).
The USN received the aircraft for trials in April of 1945 and, beyond some slight issues, the aircraft won over test pilots and authorities. With the war in Europe over in May of that year - and Japan to follow in August - the XBT2D-1 product was allowed to survive and was not cancelled as so many other programs were in the post-war drawdown. Instead, the USN cut its production order to help ease delivery of the product which was adopted as the AD-1 "Skyraider".
As such, the Skyraider missed out on combat actions in World War 2.
Skyraiders Over Korea
Nevertheless, the Skyraider was acquired in numbers significant enough to make up the strike arm of United States Navy carrier groups heading into the Korean War (1950-1953). It was also taken on by the United States Marine Corps (USMC) who could appreciate a heavy ordnance hauler for Close-Air Support (CAS). As the AD-1, Skyraider aircraft received their baptism of fire over the Korean Peninsula despite the arrival of jet fighters by this time - Skyraiders showcased better range and loitering times as well as ordnance flexibility when compared to thirsty jet fighters with limited air-to-ground armament. First actions for AD-1s were on July 3rd, 1950 from the deck of USS Valley Forge (CV-45). The Skyraider recorded its only air kill of the war on June 16th, 1953 when a USMC Skyraider claimed a Polikarpov Po-2 "Mule" biplane. Beyond its traditional bombing sorties, Skyraiders accounted for other missions inthe theater including radar jamming and night strikes. The Hwacheon Dam was struck by a torpedo released by a Skyraider back on May 2nd, 1951 - torpedo delivery being one of the Skyraiders original battlefield roles when developed. Skyraider losses in Korea totaled 128 aircraft though 27 of this total was to non-combat-related incidents - particularly tricky handling of the powerful aircraft.