B-36 Peacemaker Turns 80: No Combat Aircraft Since Has Matched Its 70-Meter Wingspan

Eighty years ago, on August 8, 1946, the prototype Convair XB-36 lifted off from Fort Worth, Texas, on a 37-minute first flight flown with the landing gear locked down throughout. The bomber that came out of that program never dropped a bomb in combat, but it set a mark that has stood ever since: no combat aircraft has been built with a longer wingspan.

The B-36 Peacemaker spanned 70 meters (230 ft), on a wing thick enough at the root, about 1.8 meters, for crew members to crawl out to the engines in flight. Six Pratt & Whitney R-4360 Wasp Major radials drove pusher propellers mounted behind the trailing edge; from the B-36D onward, four General Electric J47 turbojets were added under the outer wings, giving the type ten engines, more than any other mass-produced aircraft. Convair completed 384 airframes between 1946 and 1954.

Deliveries to Strategic Air Command began in June 1948, and the B-36 became the primary carrier for the first generation of US thermonuclear weapons, the only bomber cleared for the largest of them. Maximum range approached 16,000 km and combat radius exceeded 6,400 km, enough to reach targets inside the Soviet Union from bases in the continental United States without refueling. RB-36 reconnaissance variants flew higher and farther than any other US aircraft until the U-2 arrived, and one modified airframe, the NB-36H, carried an operating nuclear reactor aloft to test the feasibility of nuclear-powered flight.

What has never been repeated is the sheer scale. GMN specifications put the B-52 Stratofortress at 56.4 meters of span, the Tu-160 Blackjack at 55.7 meters and the B-2 Spirit at 52 meters. The B-21 Raider now entering service is smaller again, at roughly 40 meters: modern bomber design is driven by low observability rather than by the raw wing area a piston-engined aircraft needed to reach 13,000 meters. A direct comparison with the B-52 shows the trade-off, with the jet roughly 55 percent faster on eight engines but 14 meters shorter across the wing.

The B-36 never flew a combat mission. Its role was to be seen: Strategic Air Command deployed it to Britain and French Morocco to demonstrate intercontinental reach in the opening years of the Cold War. The "Peacemaker" name was submitted by Convair to a naming contest and never formally adopted by the Air Force, but it stuck for exactly that reason.

The last aircraft was retired on February 12, 1959, displaced by the jet-powered B-52 barely a decade after the type entered service. That successor is still in the inventory: GMN fleet data credits the US Air Force with 76 B-52s, 45 B-1B Lancers and 19 B-2 Spirits in 2026, plus the first three B-21 Raiders against a program of record of 100 aircraft, by some distance the heaviest bomber force among the air forces of the world ranked by fleet strength. Four B-36s survive intact, in museums at Dayton, Tucson, Ashland and Atwater.