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Royal Aircraft Factory B.E.12


The Royal Aircraft Factory B.E.12 was a British single seat aircraft of The First World War designed at the Royal Aircraft Factory.

It was essentially a single seat version of the B.E.2.

Intended for use as a long-range reconnaissance and bombing aircraft, the B.E.12 was pressed into service as a fighter, in which role it proved disastrously inadequate, mainly due to its very poor manoeuvrability.

The B.E.12 was essentially a B.E.2c with the front (observer’s) cockpit replaced by a large fuel tank, and the 90 hp RAF 1 engine of the standard B.E.2c replaced by the new 150 hp RAF 4.

The prototype a modified B.E.2c airframe fitted with the more powerful 150 hp (112 kW) RAF 4a air-cooled V12 engine was in the process of conversion in June 1915.

At the time the B.E.12 was conceived the necessity for an aircraft to defend itself was by no means as clear as it became later.

The idea of dispensing with defensive armament altogether and replacing the observer’s seat with extra fuel capacity and / or bomb load was typified by several contemporary designs, such as the bomber versions of the Avro 504, and Sopwith 1½ Strutter.

In mid 1915 there was no way for a British single seat tractor aircraft to carry a forward firing armament as the Vickers-Challenger interrupter gear did not exist until December and was not available in numbers until the following March.

The latest Royal Aircraft Factory single seat fighter of the time, the F.E.8, was a nimble little pusher proving if nothing else that its designers were very well aware of the basic requirements of a successful fighter.

Nor was the B.E.12 rushed into service as would have been relatively easy as it was a straight forward conversion of a type in production.

Trials with the prototype continued through late 1915 and seem to have been mainly concerned with the development of the new RAF 4 engine, especially the design of a satisfactory air scoop.

Cooling of the rear cylinders of the RAF 4, an air-cooled V12 and later the engine of the R.E.8, was always rather dubious.

The type was also tested as a bomber.

It was May 1916 (when the “Fokker scourge”, as a period of German air superiority was over) that it was decided to fit a synchronised Vickers gun to the type, armament trials had already been undertaken with upward firing Lewis guns, similar to those used by the night fighter version of the B.E.2c.

The B.E.12a variant flew for the first time in February 1916 and had the modified wings of the B.E.2e.

It was rather more manoeuvrable than the B.E.12 but was otherwise little improved.

The B.E.12b used the B.E.2c airframe but had the 200 hp Hispano-Suiza engine.

It was intended as a night fighter and carried wing mounted Lewis guns in place of the synchronised Vickers.

Apparently it had a good performance but the engine was more urgently needed for the S.E.5a and very few B.E.12b fighters went into service with home defence squadrons.

Some of those built may never have received engines.





27 ft 3 in (8.31 m)


37 ft 0 in (11.28 m)


11 ft 1.5 in (3.391 m)

Wing area

371 sq ft (34.5 m2)

Empty weight

1,635 lb (742 kg)


RAF 4a, V-12 air cooled piston engine,

150 hp (110 kW)


4 bladed fixed pitch wooden propeller


Maximum speed

102 mph (164 km/h, 89 kn) at sea level


3 hours

Service ceiling

12,500 ft (3,800 m)

Time to altitude

5,000 ft (1,500 m) in 11 minutes



1× .303 in (7.7 mm) synchronised Vickers machine gun

(Some aircraft carried various arrangements of rearward firing Lewis guns).


Up to 336 lb (150 kg) bombs

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