Douglas military aircraft Army. The Douglas A-20 (Havoc) light bomber, called the Boston by the British, is used by both the American Air Force and the Royal Air Force. It was designed as an attack bomber for hedge hopping and strafing operations against ground troops and installations. Because of the speed and performance abilities of this plane, the British have converted a number for use as night fighters. Some have also been used for reconnissance work. Armament details vary according to use, light and heavy guns being mounted in varying combinations