In early 1942, with the need for a purpose-built transport with better high-altitude performance and longer range than the Douglas C-47 Skytrain, the San Diego plant began sending B-24D models to Fort Worth for conversion into the C-87 transport. The conversion had a hinged cargo door at the nose eliminating transparent nose and large cargo doors installed in the waist area. The C-87 had a large cargo floor, less powerful supercharged engines, no gun turrets, a floor in the bomb bay for freight, and some side windows. The navigator's position was relocated behind the pilot. Indigenous Fort Worth C-87 and AT-22 production began with the FY 1943 order for 80 serial numbered airframes 43-30548 through 43–30627.