The Douglas A-26 Invader was a United States twin-engined light attack bomber built by the Douglas Aircraft Co. during World War II. It also saw service during several of the Cold War's major conflicts. Some models in service between 1948-1965 were designated B-26, which has led to popular confusion with the Martin B-26 Marauder. Although both types used the R-2800 engine, they are completely different designs.
The A-26 was an unusual design for an attack bomber of the early 1940s period, as it was designed as a single-pilot aircraft (sharing this characteristic with the RAF's de Havilland Mosquito, among others). The A-26 was originally built in two different configurations. The A-26B had a "solid" nose, which originally could be equipped with a combination of anything from .50 caliber machine guns, 37mm auto cannon, 20mm or even a 75mm pack howitzer, but normally the solid nose version housed six (or later eight) .50 caliber machine guns, officially termed the "all-purpose nose", later commonly known as the "six-gun nose" or "eight-gun nose". The A-26C's "glass" nose, officially termed the "Bombardier nose", contained a Norden bombsight for medium altitude precision bombing. The A-26C nose section included two fixed M-2 guns, later replaced by underwing gun packs or internal guns in the wings.
The Douglas company began delivering the production model A-26B in August 1943 with the new bomber first seeing action with the Fifth Air Force in the Southwest Pacific theater on 23 June 1944, when they bombed Japanese-held islands near Manokwari. A-26s began arriving in Europe in late September 1944 for assignment to the Ninth Air Force. Besides bombing and strafing, tactical reconnaissance and night interdiction missions were undertaken successfully. In contrast to the Pacific-based units, the A-26 was well received by pilots and crew alike in the European theater, and by 1945, the 9th AF had flown 11,567 missions, dropping 18,054 tons of bombs, recording seven confirmed kills while losing 67 aircraft.
B-26 Invaders of the 3d Bombardment Group, operating from bases in Southern Japan, were some of the first USAF aircraft engaged in the Korean War, carrying out missions over South Korea on 27 and 28 June, before carrying out the first USAF bombing mission on North Korea on 29 June 1950 when they bombed an airfield outside of Pyongyang.
The last A-26 in active US service was assigned to the Air National Guard; that aircraft was retired from military service in 1972 by the US Air Force and the National Guard Bureau and donated to the National Air and Space Museum.
Source: Wikipedia, "Douglas A-26 Invader", available under the CC-BY-SA License.