At its inception, the B-24 was a modern design featuring a highly efficient shoulder-mounted, high aspect ratio Davis wing. The wing gave the Liberator a high cruise speed, long range and the ability to carry a heavy bomb load. Early RAF Liberators were the first aircraft to cross the Atlantic Ocean as a matter of routine. In comparison with its contemporaries the B-24 was relatively difficult to fly and had poor low speed performance; it also had a lower ceiling and was less robust than the Boeing B-17 Flying Fortress. While aircrews tended to prefer the B-17, General Staff favored the B-24, and procured it in huge numbers for a wide variety of roles.[4][5] At approximately 18,500 units – including over 4,600 manufactured by Ford Motor Company – it holds records as the world's most produced bomber, heavy bomber, multi-engine aircraft, and American military aircraft in history.The B-24 was used extensively in World War II. It served in every branch of the American armed forces, as well as several Allied air forces and navies, and saw use in every theater of operations. Along with the B-17, the B-24 was the mainstay of the U.S. strategic bombing campaign in the Western European theater. Due to its range, it proved useful in bombing operations in the Pacific, including the bombing of Japan. Long range anti-submarine Liberators played an instrumental role in closing the Mid-Atlantic gap in the Battle of the Atlantic.