The Gloster Gauntlet was a British single-seat biplane fighter of the RAF.
It was the last RAF fighter to have an open cockpit and the penultimate biplane fighter in service.
The Gauntlet had a somewhat lengthy development process, linking back to the S.S.18 prototype of 1929.
Extensive modifications, including multiple engine changes and changes to suit varying specifications, resulted in a relatively fast fighter aircraft for the era as well as a heavy armament and favourable manoeuvrability.
By mid-1933, the Gauntlet name had been applied to the type and the Air Ministry placed an initial order for 24 aircraft during September of that year.
It was procured as a replacement for the Bristol Bulldog, being roughly 50 MPH faster while also being more heavily armed.
In May 1935, No. 19 Squadron became the first unit to receive the Gauntlet I.
An improved model, the Gauntlet II, featuring structural improvements sourced from Gloster’s new parent company, Hawker was developed during 1934; deliveries of this new model commenced in the following year.
Gloster received orders for over 200 Gauntlet IIs, with the type eventually being operated by 14 RAF squadrons of RAF Fighter Command.
It was used for various duties, including a secretive series of exercises that included the first interception of an aircraft using information relayed from ground-based radar, a technique that would prove to be vital during the Second World War.
However, as early as 1936, frontline squadrons begun to be reequipped with more advanced fighters, such as the Gloster Gladiator, Hawker Hurricane and Supermarine Spitfire.
Gauntlets were increasingly used in secondary roles and by overseas squadrons, serving in a reduced capacity into the Second World War.
The last examples were withdrawn during 1943.
The Gloster Gauntlet can be traced back to the S.S.18 prototype, which made its maiden flight during January 1929.
While its performance had proven the basic design to be sound, having demonstrated a maximum speed of 189 MPH, difficulties with the Bristol Mercury IIA engine that powered the aircraft motivated Gloster to explore other powerplants, which ultimately resulted in the structurally similar Gloster S.S.19.
Around this time, the Air Ministry was formulating Specification F.10/27, which called for a single-seat fighter aircraft that was to be armed with six machine guns and function as a high-altitude interceptor; Henry Folland, Gloster’s chief designer, opted to modify the S.S.19 to carry a heavier armament (four machine guns in the wings and two in the fuselage), in order to conform with these requirements.
Extensive trials of the aircraft were conducted at RAF Martlesham Heath during late 1930, in which it was found to be free of major detects and to have superior handling to any single-seat aircraft up to that point.
Despite the S.S.19’s promising performance, attitudes within the Air Staff as to what the armaments of the prospective future fighter had shifted, and changes were requested.
Folland decided to respond by refining the aircraft’s design, such as the addition of mainwheel spats, a spatted tailwheel, and a modified tail unit with greater fin area and thus increased stability.
Re-designated as the S.S.19A, the aircraft underwent a full-service evaluation during late 1931, during which it achieved a top speed of 204 mph (328 km/h).
Further modifications were made to satisfy Specification F.20/27, resulting in the Gloster S.S.19B.
Evaluation flights of this revision revealed the aircraft to possess a maximum speed of 212 mph (341 km/h).
By the summer of 1933, testing had progressed with the S.S.19B and plans to procure the type had advanced to the point where the Gauntlet name was assigned to the type.
Having been re-engined with a Bristol Mercury VIs engine, the type proved itself capable of a top speed of 215.5 mph (346.8 km/h) as well as attaining an altitude of 20,000 feet in 11 minutes and 43 seconds.
Having been sufficiently satisfied by the demonstrated performance, the Air Ministry opted to place an initial order via a draft production schedule for 24 Gauntlets as a replacement for one squadron of Bristol Bulldog fighters during September 1933; both the finalised specification and contract No. 285263/35 were issued to Gloster in February 1934.
The aircraft was fitted with a 450-hp (336-kW) Bristol Mercury IIA radial piston engine.
The SS.18 was fitted with a 480 hp (358 kW) Bristol Jupiter VIIF radial piston engine.
The SS.18 was later fitted with a 560 hp (418 kW) Armstrong Siddeley Panther III radial piston engine.
Single-seat prototype; fitted with a Bristol Jupiter radial piston engine.
The SS.19 was later fitted with two-wheel spats and a single spatted tail wheel.
Single-seat prototype; fitted with a 536 hp (400 kW) Bristol Jupiter VIS radial piston engine.
Gauntlet Mk I
Single-seat fighter aircraft for the RAF.
Gauntlet Mk II
Single-seat fighter aircraft; modified version of the Gauntlet Mk I.