Bristol Bagshot

Bristol Aeroplane Company

Industry	Aerospace
Founder	Frank Barnwell (designer)
Headquarters	Filton , United Kingdom

The Bristol Bagshot, designated as the Type 95, was a British twin-engine fighter prototype developed by the Bristol Aeroplane Company and conducted its maiden flight in 1927. Testing revealed significant deficiencies, ultimately leading to the cessation of the project.

Development

Conceived in response to the Air Ministry Specification F.4/24 issued in December 1924, the Bagshot was intended as a large twin-engine fighter featuring a crew of three—pilot plus two gunners—with a maximum speed target of 125 mph (201 km/h) and a landing velocity around 50 mph (80 km/h). Armament details were initially unspecified. Designed by Frank Barnwell, the Bagshot was characterized by a high-wing, all-metal monoplane layout, incorporating an unconventional triangular-section fuselage constructed from fabric-covered steel tubing with two upper longerons and a single lower member. The pilot's cockpit was aligned with the wing's leading edge, while gun positions were arranged in the nose and just aft of the wing. Its wing featured two spars with a steel main framework combined with duralumin nose ribs and end components; it was a semi-cantilever type supported by pairs of diagonal struts on each side. The fixed undercarriage legs attached at the same point as these struts, with an airfoil-shaped axle fairing that contributed lift. Propulsion came from two wing-mounted 450 hp (340 kW) Bristol Jupiter VI engines.

In September 1925, modifications to the specification required engine superchargers, increased fuel capacity, and improved high-altitude speed. Barnwell participated in a design meeting where it was clarified that the aircraft was to carry two Coventry Ordnance Works COW 37 mm guns, commonly referred to as COW guns. Upon receiving full armament requirements—which included two additional Lewis guns—Barnwell recognized that the resulting weight increase would elevate the landing speed to approximately 57 mph (92 km/h). He proposed an alternative fuselage constructed from rolled steel strip to reduce weight and recommended abandoning the project if load tests failed. Despite these concerns, the Air Ministry insisted on continuation, leading to completion of the Bagshot, which was provisionally accepted on 12 May 1927 and assigned serial number J7767.

Operational history

The Bagshot's maiden flight took place unarmed at Filton on 15 July 1927, piloted by Bristol's chief test pilot, Cyril Uwins. This initial sortie was brief, which Archibald Russell—then working in the stress analysis department at Filton and later knighted—considered an unfavorable indicator. Uwins noted inadequate control over the roll axis during the flight. On a subsequent attempt, as Uwins accelerated to 100 mph (160 km/h), the control difficulties intensified. Due to a prior neck injury from an aviation accident, Uwins was unable to directly monitor the wing's behavior. Consequently, it was deemed safe enough to include an observer on board if speed remained limited. Russell, who had recently focused on measuring wing spar deflections under load, was assigned this task. Positioned in the rear gunner’s station, he had an unobstructed view of the wing and established a straightforward hand signal communication method with Uwins. By the time they reached the predetermined speed and altitude for testing, Russell was deeply troubled by the pronounced and unsettling "writhing movements" of the wing. However, lacking a signal to halt the test, Uwins completed the entire flight schedule. The investigation determined that control reversal caused by wing twisting when operating the ailerons was responsible for these issues. Following this, the aircraft was grounded for structural testing. It was later transferred to the Air Ministry’s experimental unit and briefly flown again in 1931 before being dismantled and scrapped.