The Bristol F.2.B of World War 1
On 25 October 1916, the second prototype was completed, powered by a Hispano-Suiza engine, and otherwise differing from the first prototype in its tail-skid, which was integrated into the base of the rudder.
It was found that the prototype’s radiator arrangement obscured the pilot’s field of view, and the nose was redesigned around a new circular-shaped frontal radiator housed within the cowling.
Other changes made to the first prototype during flight testing included the elimination of the end-plates from the lower wing roots and the addition of a shallow coaming around the cockpits.
Between 16 and 18 October 1916, the type underwent its official trials at the Central Flying School, Upavon, during which it was tried with both a four-bladed 9 ft 2 in the propeller and a two-bladed 9 ft 8 in the propeller.
By the time of its arrival at the experimental armament station at Orfordness, it had also been fitted with a Scarff ring mounting over the rear cockpit and an Aldis optical sight.
Only 52 F.2A aircraft were manufactured before production was switched to the definitive model, the F.2B (retrospectively designated Bristol Type 14 which first flew on 25 October 1916.
The first 150 or so F.2Bs were powered by either the Falcon I or Falcon II engine, but the remainder were equipped with the 275 hp (205 kW) Falcon III engine.
The additional power gave the F.2B a 10 mph (16 km/h) advantage in level speed over the F.2A, while it was three minutes faster in a climb to 10,000 ft (3,000 m).
Armament The Bristol F.2 Fighter was armed in what had by then become the standard weapons configuration for a British two-seater military aircraft: one synchronised fixed, forward-firing .303 in (7.7 mm) Vickers machine gun (in this case mounted under the cowling to avoid freezing) and a single flexible .303 in (7.7 mm) Lewis Gun on a Scarff ring over the observer’s rear cockpit.
The F.2B variant often carried a second Lewis gun on the rear cockpit mounting, although observers found the weight of the twin Lewis gun mounting difficult to handle in the high altitudes at which combat increasingly took place in the last year of the war, many preferring to retain a single gun.
Bristol Fighter with Foster-mounted Lewis gun Attempts was made to add a forward-firing Lewis gun on a Foster mounting or similar on the upper wing either instead of, or in addition to, the Vickers gun.
Among other problems, this caused interference with the pilot’s compass, which was mounted on the trailing edge of the upper wing: to minimise this effect the Lewis gun was offset to starboard.