At the start of the Second World War the US Army Air Corps lacked a modern radar equipped night fighter, and so it was decided to copy the RAF and convert a number of Douglas A-20s. Under the rarely used name “Nighthawk” 270 P-70s were produced. Most were used for training purposes, but a number found their way to the South Pacific, where they were used by the 6th, 418th, 419th and 412th Night Fighter Squadrons, first as defensive night fighters and later as intruders. The P-70 was never really a satisfactory night fighter, lacking the high altitude performance to catch Japanese raiders, but it did help to prepare the way for the P-61 Black Widow and was used to train nineteen night fighter squadrons.
The prototype XP-70 was produced by adding British AI Mk IV radar to the nose of an A-20. The supercharged engine of the A-20 was replaced by an R-2600-11, which reduced the high altitude performance of the XP-70, and thus its usefulness as a night fighter. With the radar in the glass nose, firepower was provided by four 20mm cannon in a ventral tray under the bomb bay. The XP-70 carried a crew of two, with the radar operator in the rear gunner’s compartment.
Despite the unimpressive performance of the XP-70, no other aircraft were immediately available and so 59 of the remaining A-20s were turned into P-70 “Nighthawks”. These aircraft were virtually identical to the XP-70. Most remained in the United States, where they were used as training aircraft, but some were used by the 6th Night Fighter Squadron in the South Pacific. The P-70s were delivered between April and September 1942.
The thirty nine P-70A-1s were converted from A-20Cs during 1943. The main change from the P-70 was the use of six or eight 0.50in machine guns in place of the 20mm cannons of the earlier aircraft, the cannons have proved troublesome on the P-70 and on the first A-20Gs.
Sixty five P-70A-2s were produced by fitting radar to early production solid nosed A-20Gs. These aircraft were of the second type of A-20G, armed with six 0.50in machine guns in the nose (most of the cannon armed A-20Gs having gone to the Soviet Union). Most of these aircraft were used for training, but some did reach the 6th Night Fighter Squadron in the Pacific.
One P-70B-1 was produced by fitting American SCR-720 centimetric radar in the nose of a modified A-20G. The P-70B-1 was armed with six 0.50in machine guns, carried in two blister packs on the lower side of the fuselage, below the cockpit.
Finally 105 A-20Gs and A-20Js were converted into P-70B-2s, the vast majority of which were used for training purposes. Most carried the ACR-720 radar used in the B-1, while others were equipped with ACR-729 radar. The P-70B-2s carried a wide range of guns. The dorsal turret was kept on some and removed on others. The ventral gun pod was carried, armed with six or eight 0.50in machine guns, while some aircraft also carried the blister packs on the side of the fuselage.
The first squadron to use the P-70 in combat was the 6th Night Fighter Squadron, which received its first aircraft in September 1942. At first it operated from Hawaii, but early in 1943 two detachments moved to Guadalcanal and New Guinea, taking the P-70 into combat.
Detachment “B” was first to go, moving to Guadalcanal in February 1943. Its job was to protect the Marines against an increasing number of Japanese night intruder raids, but the P-70 really lacked the performance to catch the elusive enemy. Despite this on 19 April 1941 Captain Earl C. Bennet and radio operator Edwin E. Tomlinson scored the USAAF’s first night fighter victory when they shot down a Mitsubishi G4M Betty. A second victory, over a biplane float-plane, followed on 16 August 1943, before on 15 November the detachment was joined by the 419th Night Fighter Squadron. By that point most of the detachment’s P-70s had been swapped for P-38s, while the 419th NFS used its P-70s as intruders, flying offensive sorties over Japanese held territory.
Detachment “A” was sent to New Guinea, to help defend Port Moresby. It reached its new base at “3-mile strip” on 1 April 1943, but had to wait until 15 May for its first victory, when a Mitsubishi Ki-21 Sally was destroyed by 20mm cannon fire. This was the detachments only victory before it was absorbed by the 418th Night Fighter Squadron at the end of November 1943.
The 418th was joined by the 421st Night Fighter Squadron in January 1944. As on Guadalcanal the New Guinea based P-70s were used on intruder missions during 1944, before being replaced by the P-61 in June 1944.
The P-70 was probably the least successful version of the DB-7/ A-20 family, but it did at least give American night fighter crews some valuable practical experience of operating a radar equipped aircraft at night, and prepared them for the arrival of the purpose-built P-61.