B-25C 41-12800 in flight
The B-25C and D were the first production models to see combat action. Despite being virtually identical, they were differentiated only by the suffix to denote their respective manufacturing sites, with the B-25C-NA built in Inglewood and the B-25D-NC in Fairfax Field, Kansas City. From the outside, the B-25C/D looked similar to the earlier B-25B, with only a minor difference in the rear fuselage bumper giving away the variant. However, significant changes had been made to the original design, including the installation of a pair of 1,700 hp (1,268 kW) R-2600-13 engines to cope with the increased weight. The first batch of planes also had a new de-icing system, stronger wing panels, and the addition of self-sealing 152-gallon fuel tanks in each wing (576 liters in total), which increased the bomber’s range. Later production models included modified exhaust systems, cabin heaters, provisions for a fuel tank in the bomb bay, and underwing racks for bombs and torpedoes. The B-25C/D was also 10 inches shorter (25.4 cm) than its predecessor, and from the 383rd aircraft onwards, it had a navigator’s astrodome. Initially, the armament was the same as the B-25B, but later on, the nose gun was upgraded from a single machine gun to a pair of 0.5-inch guns. The B-25C made its first flight in November 1941, followed by the B-25D in January 1942.