Original author: Spark1645.

The Douglas A-20F was the designation given to a version of the Havoc armed with a large 37mm gun in the nose, built on a modified A-20A chassis. Sources disagree on the numbers that were actually constructed. At least one was produced with upper and lower General Electric remote controlled turrets.

Photographs exist of what may be two different aircraft or the same aircraft at different stages of development. One shows an aircraft number 67, armed with the nose cannon, and with the fitting for the upper turret visible but no turret installed, while a second picture shows aircraft number 69, named Porcupine I, armed with both upper and lower turrets. The numbers might indicate different aircraft or different stages of development of the same aircraft. The second alternative seems most likely.