The Adolphe Bernard AB was a twin-engined

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

aircraft, built near the end of the

First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

. Ten AB 1 BN2 bombers were produced for the

Armée de l'Air The French Air and Space Force (, , ) is the air force, air and space force of the French Armed Forces. Formed in 1909 as the ("Aeronautical Service"), a service arm of the French Army, it became an independent military branch in 1934 as the Fr ...

but did not reach squadron service; post-war, two civil derivatives were considered but only one aircraft was built.

Design and development

The AB 1, built near the end of the First World War, was the first original design from the Adolphe Bernard factory, which had previously produced SPAD aircraft to government contracts. It was a twin engine biplane bomber, carrying of bombs.Liron, 1990, pp.145, 215, 224 The AB 1 BN2 was a wooden three bay biplane, without stagger but with greater span on the upper planes. Only the lower wings carried dihedral. The outer and mid

interplane struts In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of struts, which act in ...

were outward leaning pairs but the inner bay was defined by a complex of struts supporting the engines midway between the wings. Head on, these appeared as a V based on the lower wing but had M and W arrangements seen side-on above and below the engine. The AB 1 used

Hispano-Suiza Hispano-Suiza () is a Spanish automotive company. It was founded in 1904 by Marc Birkigt and as an automobile manufacturer and eventually had several factories in Spain and France that produced luxury cars, aircraft engines, trucks and weapons. ...

V-8 piston engines, of which type there was a surplus after the

Armistice An armistice is a formal agreement of warring parties to stop fighting. It is not necessarily the end of a war, as it may constitute only a cessation of hostilities while an attempt is made to negotiate a lasting peace. It is derived from t ...

. It had

ailerons An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

on both upper and lower wings, externally connected. The fuselage of the AB 1 BN2 was flat-sided, with a narrowed but flat topped decking. There was a gunner's position in the extreme nose fitted with a machine gun on a TO 4 mounting. The fuselage tapered rearwards with the

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

tailplane, which carried separate

elevators An elevator (American English) or lift (English in the Commonwealth of Nations, Commonwealth English) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive tracti ...

, mounted on top. The

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...

carried a horn balanced rudder which extended down to the bottom of the fuselage, moving between the elevators. Its main undercarriage had a wide track, with twin wheels on short axles mounted below each engine on inverted V struts, themselves further braced to the lower fuselage

longerons In engineering, a longeron or stringer is a load-bearing component of a framework. The term is commonly used in connection with aircraft fuselages and automobile chassis. Longerons are used in conjunction with stringers to form structural frame ...

. The first AB 1 BN2 was built in 1918 and probably flew that year. There were plans for a variant using more powerful

Hispano-Suiza 8Ba The Hispano-Suiza 8 is a water-cooled V8 SOHC aero engine introduced by Hispano-Suiza in 1914 that went on to become the most commonly used liquid-cooled engine in the aircraft of the Entente Powers during the First World War. The original Hisp ...

engines, the AB 2, but this was not built. Post war, two civilian variants were started, the post-carrying AB 3 and the passenger only or passenger plus post AB 4. The AB 3, one of which was completed in 1920, could carry a useful load of . The AB 4, which had the same engines as the proposed AB 2, carried a maximum of seven passengers. Its fuselage was on display at the 6th Paris Aero Show in December 1919, but it was not completed.Flight, 1920, pp.10–11

Operational history

Ten AB 1s were produced after the

but do not seem to have achieved squadron service.

Variants

;AB 1 BN2 :Night Bomber to the 1918 BN2

Service Technique de l'Aéronautique The (STAé) was a French state body responsible for coordinating technical aspects of aviation in France. Formed in 1916 as the the STAé continued until 1980 when its functions were distributed among other French governmental bodies, includin ...

(STAe) specification, as supplied to the

, powered by two

Hispano-Suiza 8 Ab The Hispano-Suiza 8 is a Internal combustion engine cooling, water-cooled V8 engine, V8 SOHC aero engine introduced by Hispano-Suiza in 1914 that went on to become the most commonly used liquid-cooled engine in the aircraft of the Entente Powers ...

water-cooled v-8 engines:Eleven built. ;AB 2 :Proposed version with

engines: Not built. ;AB 3 :Post carrying civil version of AB 1, powered by two

engines, with span wings: One built 1920. ;AB 4 :Airliner/post carrier version of AB 2, powered by two

engines. Maximum seven passengers, depending on postal load: One partly built 1919.

Specifications (AB 1 BN2)

References

Citations

Bibliography

* * * * {{Bernard aircraft 1910s French bomber aircraft AB001 Biplanes Aircraft first flown in 1918 Twin piston-engined tractor aircraft