FSX/P3D v3,v4 IIyushin Il-4. The DB-3F was redesignated Il-4 in March 1942. The most notable change was the addition of larger defensive guns in the turret, using the 12.7 mm (0.5 in) UBT machine gun in place of the earlier 7.62 mm (0.3 in) weapons. Although the Il-4 was only a medium bomber, it could be used on strategic missions. FSX/Prepar3D v3,v4 model by A.F. Scrub.