Historical Note:  

The Douglas A-26 Invader (designated B-26 between 1948 and 1965) is a twin-engined light bomber and attack aircraft built by Douglas Aircraft during World War II which also saw service during several major Cold War conflicts. A limited number of highly modified US Air Force aircraft (designation A-26) served in combat until 1969.^{[clarification needed]}

It was found to be a fast aircraft capable of carrying twice its specified bomb load. A range of guns could be fitted to produce a formidable ground-attack aircraft.

The re-designation of the type from A-26 to B-26 has led to popular confusion with the Martin B-26 Marauder, a design that first flew in November 1940, some 16 months before the Douglas design's maiden flight. Although both types utilized the much-used Pratt & Whitney Double Wasp eighteen-cylinder, double-row engine, they were completely different designs. The last A-26 in active US service was assigned to the Air National Guard; that aircraft being 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.

Info: B-26K Counter Invader 609th SOS, 59th SOW, Thailand 1969