C-108 Flying Fortress

The C‑108 Flying Fortress was a transport conversion of the legendary B‑17 bomber, produced by Boeing during World War II. In 1942 the United States Army Air Forces ordered a series of B‑17Es to be modified for cargo and personnel ferry duties, creating the C‑108A, C‑108B, and later the C‑108D “Flying Fortress”. The conversion removed armament, armor and bomb‑bay equipment, replacing them with reinforced floor beams, a large cargo door, and a dual‑crew cockpit to accommodate up to 30 passengers or bulky freight such as engines, ammunition and medical supplies. Powered by four Wright R‑1820‑97 Cyclone radial engines delivering 1,200 horsepower each, the aircraft retained the original B‑17’s robust airframe, long range of 2,000 miles, and a cruising speed of 230 mph, giving it the ability to operate from forward airfields with limited infrastructure. Although only 27 airframes were completed, the C‑108 proved essential for rapid logistical support in the European and Pacific theaters, moving critical materiel and personnel where conventional transports were scarce. Its versatility demonstrated how a combat‑proved bomber could be repurposed, influencing post‑war cargo aircraft design and highlighting Boeing’s adaptability in meeting emerging military transport needs.