While the German Luftwaffe operated many different aircraft during World War II, none were more prominent than the Messerschmitt Bf-109 fighter. A technological marvel when it first flew in 1935, the Bf-109 served on all fronts through the entire war, and was produced in great quantity even as it was becoming increasingly obsolescent relative to Allied fighters

The "Bf-109G" was direct follow-on to the Bf-109F. The "Gustav", as it came to be known, was fitted with the still more powerful DB-605-series engine, with was effectively a DB-601 with bored-out cylinders, higher compression, and 1,082 kW (1,450 HP) for takeoff. The new engine was heavier and generated higher torque, requiring airframe reinforcement and modifications. Some Gustav variants also featured a pressurized cockpit. Initial deliveries of the Gustav began in early 1942. The Bf-109G-6 was the most heavily produced of the Gustavs, with different subvariants using different versions of the DB-605. It was sometimes fitted as a Jabo but particularly used as a bomber destroyer, with the "gunboat" modifications.