
The Bristol Type 133 after its first flight, showing open cockpit and full span ailerons/flaps.
The Bristol 133 was a prototype single-seat monoplane fitted with a single engine and retractable undercarriage. It was the second offering from the Bristol Aerplance Company (after the Rolls-Royce Goshawk-powered Bristol Type 123 biplane) against Air Ministry Specification F.7/30 calling for a four-gun day and night fighter.
The Type 133 used a 620hp Bristol Mercury VI engine and was that of an inverted gull-wing configuration, with fairings for the retractable main wheels, mounted from the ‘knuckle’ of the wing.
The first Type 133 (R-10) with an open cockpit, was first flown by Bristol test pilot Cyril Unwins on 8th June 1934. A cockpit enclosure was subsequently fitted. Another striking feature included a monocoque rear fuselage and (initially), full span ailerons that could be symmetrically drooped as flaps.

A side view of the Type 133 R-10 fitted with an enclosed cockpit canopy.
The aircraft later reverted to more conventional ailerons with split flaps under the centre-section. The clean engine cowling featured a long-chord Townend-ring cowling, with an integral exhaust collector-ring.

The Bristol Type 133 looked elegant in flight, like a precursor of the Vought Corsair.
Sadly, the Type 133 did not actually reach the Aeroplane & Armament Experimental Establishment (A&AEE) at Martlesham Heath for official trials, being lost in a spinning accident on 8th March 1935, with the pilot escaping by parachute. Apparently, the problem occurred whilst spinning with the undercarriage down and it was evident that when the aircraft entered a flat spin, it had very little forward speed when it struck the ground.

The promising Bristol Type 133 came to a sad end during its spinning trials.
The Hawker Hurricane, which flew barely six months after the Bristol Type 133, was a much more mature design and carried twice the gun armament. However, Specification F.7/30 was eventually awarded to the Gloster Gladiator
Consequently, it is considered unlikely that despite its initial potential, the Type 133 would ever have been selected for RAF service.
Specification
Powerplant | One 640 hp Bristol Mercury VIS.2 |
Span | 39 ft 0 in |
Maximum Weight | 4,738 lb |
Capacity and armament | Pilot only; four forward firing Vickers machine guns |
Maximum Speed | 260 mph equipped |
Variants
Single example only, flown marked as R-10.
Survivors
None (prototype destroyed during spinning trials in March 1935).