Consolidated B-24 Liberator - Design

Design

The B-24's spacious, slab-sided fuselage (which earned the aircraft the nickname "Flying Boxcar") was built around a central bomb bay with two compartments that could accommodate up to 8,000 lb (3,629 kg) of ordnance each. The bomb bay was divided into front and rear compartments and had a central catwalk just nine inches wide, which was also the fuselage keel beam. A universal complaint arose over the extremely narrow catwalk. The aircraft was sometimes disparaged as "The Flying Coffin" because the only entry and exit from the bomber was in the rear and it was almost impossible for the flight crew and nose gunner to get from the flight deck to the rear when wearing parachutes. An unusual set of "roller-type" bomb bay doors, which operated very much like the movable enclosure of a rolltop desk, retracted into the fuselage, creating a minimum of aerodynamic drag to keep speed high over the target area.

Like the B-17, the B-24 had an array of .50 caliber (12.7 mm) M2 Browning machine guns in the tail, belly, top, sides and nose to defend it from attacking enemy fighters. However, unlike the B-17, the ball turret could be retracted into the fuselage when not in use, a necessity given the low ground clearance of the fuselage. The ball turret first appeared on B-24Ds sometime in early 1943 but not before the early Ds had used tunnel guns and the Bendix remote controlled ventral turret, also used (unsuccessfully) on the initial B-17E examples and on some early B-25 Mitchell medium bombers. General use of the ball turrets by the U.S. would last until late July 1944 when performance gains outweighed the need for 360 degree belly defense. Bomber command Liberators generally dispensed with the belly turrets as unnecessary in areas where no enemy fighter presence would be found.