Boeing B-17 Flying Fortress in the context of "Electronic-warfare aircraft"

The Boeing B-29 Superfortress is a retired American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Boeing B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. Silverplate B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat.

One of the largest aircraft of World War II, the B-29 was designed with state-of-the-art technology, which included a pressurized cabin, dual-wheeled tricycle landing gear, and an analog computer-controlled fire-control system that allowed one gunner and a fire-control officer to direct four remote machine gun turrets. The $3 billion cost of design and production (equivalent to $52 billion in 2024), far exceeding the $1.9 billion cost of the Manhattan Project, made the B-29 program the most expensive of the war. The B-29 remained in service in various roles throughout the 1950s, being retired in the early 1960s after 3,970 had been built. A few were also used as flying television transmitters by the Stratovision company. The Royal Air Force flew the B-29 with the service name Washington from 1950 to 1954 when the jet-powered Canberra entered service.

The Consolidated B-24 Liberator is an American heavy bomber, designed by Consolidated Aircraft of San Diego, California. It was known within the company as the Model 32, and some initial production aircraft were laid down as export models designated as various LB-30s, in the Land Bomber design category.

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. 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. At approximately 18,500 units – including 8,685 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.

In military terminology, friendly fire or fratricide is an attack by belligerent or neutral forces on friendly troops while attempting to attack enemy or hostile targets. Examples include misidentifying the target as hostile, cross-fire while engaging an enemy, long range ranging errors or inaccuracy. Accidental fire not intended to attack enemy or hostile targets, and deliberate firing on one's own troops for disciplinary reasons is not called friendly fire, and neither is unintentional harm to civilian or neutral targets, which is sometimes referred to as collateral damage. Training accidents and bloodless incidents also do not qualify as friendly fire in terms of casualty reporting.

Use of the term friendly in a military context for allied personnel started during the First World War, often when shells fell short of the targeted enemy. The term friendly fire was originally adopted by the United States military; S.L.A. Marshall used the term in Men Against Fire in 1947. Many North Atlantic Treaty Organization (NATO) militaries refer to these incidents as blue on blue, which derives from military exercises where NATO forces were identified by blue pennants and units representing Warsaw Pact forces by red pennants. In classical forms of warfare where hand-to-hand combat dominated, death from a "friendly" was rare, but in industrialized warfare, deaths from friendly fire are more common.

The Boeing Model 307 Stratoliner (or Strato-Clipper in Pan American service, or C-75 in USAAF service) is an American stressed-skin four-engine low-wing tailwheel monoplane airliner derived from the B-17 Flying Fortress bomber, which entered commercial service in July 1940. It was the first airliner in revenue service with a pressurized cabin, which, along with supercharged engines, allowed it to cruise above the weather. As such it represented a major advance over contemporaries, with a cruising speed of 220 mph (350 km/h) at 20,000 ft (6,100 m) compared to the Douglas DC-3's 160 mph (260 km/h), at 8,000 ft (2,400 m) then in service. When it entered commercial service it had a crew of five to six, including two pilots, a flight engineer, two flight attendants, and an optional navigator and had a capacity for 33 passengers, which later modifications increased, first to 38, and eventually to 60.