The Bréguet Leviathan was a family of large all-metal biplane aircraft built in France in the early 1920s.
The Bréguet XX and XXI were notable for being powered by Bréguet-Bugatti multiple engines, in two forms.
The Bréguet XXI was powered by individual Bréguet-Bugatti U.16 engines initially and Lorraine-Dietrich 8b engines in tandem later.
The Bréguet XXII had accommodation for about twenty passengers and was destroyed during a 1923 transport aircraft competition.
Development of all three aircraft types was halted largely due to technical issues with power-plants and aircraft structure.
In 1922 Bréguet Aviation flew their all-metal Bréguet 19, a bomber/reconnaissance aircraft and the Bréguet XX.
The latter was another all-metal biplane but much larger and powered by a Bréguet-Bugatti 32A Quadimoteur Type A, this was two Bréguet-Bugatti U.24 engines mounted in tandem on a cradle, driving a single output shaft, for the first time on 20 June 1922.
The engine assembly was placed in the forward fuselage and drove the nose-mounted single propeller via a shaft running through the forward engine half’s cylinder banks from the combining gearbox between the two engine halves.
A bomber variant, the Bréguet XXI, was also built with limited success; the partially built fuselage was displayed at the 1921 Paris Aero Salon, clearly showing the installation of the Bréguet-Bugatti 32A Quadimoteur Type A engine.
The Bréguet XXI was later fitted with a Bréguet-Bugatti 32B Quadimoteur Type B, which grouped four 8-cylinder banks around a combining gearbox in an ‘H’ configuration.
Bréguet XX Leviathan
(Bréguet 20 Leviathan)
A large all-Duralumin biplane airliner powered by a Bréguet-Bugatti 32A Quadimoteur Type A multi-engine, mounted inside the forward fuselage.
Bréguet XXI Leviathan
(Bréguet 21 Leviathan)
A bomber version of the Bréguet XX / XXII, powered initially by a Quadimoteur Type A multi-engine, but later fitted with a Bréguet-Bugatti 32B Quadimoteur Type B multi-engine, both mounted inside the forward fuselage.
Bréguet XXII Leviathan
(Bréguet 22 Leviathan)
A development of the Bréguet XX powered initially by two individual Bréguet-Bugatti U.16 engines mounted conventionally between the wings and later by four Lorraine-Dietrich 8B V-8 engines mounted in tandem between the wings.
25 including crew
14.016 m (46 ft 0 in)
25.538 m (83 ft 9 in)
5.135 m (16 ft 10 in)
140 m2 (1,500 sq ft)
3,150 kg (6,945 lb)
6,400 kg (14,110 lb)
1,500 l (396 US gal; 330 imp gal)
2 × Bréguet-Bugatti U.16 U-16, (two straight-eight engines in parallel), water-cooled inline piston engines, 360 kW (480 hp) each