The Douglas A-20 Havoc, derived from their DB-7 design, also flew as the Boston. Some were reequipped and redesignated P-70, for use as an interim night fighter while the P-61 was being developed. The US nickname was always Havoc; most sources agree that that name came from the British, who applied it to the night intruder and the nightfighter versions. An alternate version is that when they took off the glass nose and put on the gun nose the Boston became the Havoc, as in "Cry 'Havoc!', and let slip the dogs of war." The gun-nosed version would certainly seem to fit the "dogs of war" description.

A preliminary draft version of the Aviation Design Analysis article [ PDF, 11.5 MiB ], recovered from microfilm, is included. An HTML version, with illustrations recovered from the magazine [ HTML ], is also provided.
The design analysis from Air Tech [ HTML ] is also included.

Combat experience and the availability of improved engines led to the development of the A-26 Invader.