Heavy bomber

Heavy bombers are bomber aircraft with the greatest bomb load carrying capacity and longest range of their time. They have also typically been among the largest size aircraft in contemporary military or civil service. Delivery of the largest possible amount of air-to-ground weaponry over long distances to strike enemy targets is the heavy bomber's mission (see also strategic bomber).

The type was first developed in World War I but came to prominence during World War II, when advancements in powerplants and aircraft design enabled four-engined bombers to attack industrial targets in Germany and Japan. Availability of such large, long range aircraft in mass-produced quantity also allowed methodologies of strategic bombing to be developed and employed during the 1940s. Parallel mid-war developments as well enabled the much smaller typical fighter aircraft to carry an increased 2,000-pound (910 kg) bomb load, and fighter-bombers were taking over from light and medium bombers in the tactical bombing role. In August 1945, the U.S. B-29 heavy bombers delivered two atomic bombs against enemy targets.