The Bristol Bombay was a British troop transport aircraft adaptable for use as a medium bomber flown by the Royal Air Force (RAF) during the Second World War.
The Bristol Bombay was built to Air Ministry Specification C.26/31 which called for a monoplane bomber-transport aircraft to replace the Vickers Valentia biplane in use in the Middle East and India.
The aircraft was required to be capable of carrying 24 troops or an equivalent load of cargo as a transport, while carrying bombs and defensive guns for use as a bomber.
This dual-purpose design concept was common to British pre-war designs.
Other entries for the specification were the Armstrong Whitworth A.W.23 and the Handley Page HP.52.
Bristol’s design, the Type 130, was a high-wing cantilever monoplane of all-metal construction.
Bristol’s previous monoplane design, the 1927 Bagshot, had suffered from lack of torsional rigidity in the wings leading to aileron reversal.
This led to an extensive research program at Bristol which resulted in a wing design with a stressed metal skin rivetted to an internal framework consisting of multiple spars and the ribs.
This was the basis of the Bombay’s wing, which had seven spars, with high-tensile steel flanges and alclad webs.
The aircraft had a twin-tail and a fixed tailwheel undercarriage.
The aircraft’s crew consisted of a pilot, who sat in an enclosed cockpit, a navigator/bomb-aimer, whose working position was in the nose, and a radio-operator/gunner, who divided his time betwixt the radio operator’s position behind the cockpit and a gun turret in the nose.
When the aircraft was operated as a bomber, an additional gunner was carried to man the tail gun position.
In the prototype, this position was equipped with a Lewis gun on a Scarff ring but in production aircraft, both gun positions were hydraulically operated gun turrets each armed with a Vickers K machine gun.
Eight 250-pound (110 kg) bombs could be carried on racks under the fuselage.
A prototype Type 130 was ordered in March 1933 and first flew on 23 June 1935, powered by two 750 horsepower (560 kW) Bristol Pegasus III radial engines driving two-bladed propellers.
Testing was successful and an order for 80 was placed as the Bombay in July 1937.
These differed from the prototype in having more powerful (1,010 hp (750 kW)) engines driving three-bladed Rotol variable-pitch propellers, discarding the wheel spats fitted to the undercarriage main wheels in the prototype.
As Bristol’s Filton factory was busy building the more urgent Blenheim light bomber, the production aircraft were built by Short & Harland (owned by Short Brothers and Harland and Wolff) of Belfast.
The complex nature of the Bombay’s wing delayed production at Belfast.
The first Bombay was not delivered until 1939 and the last 30 were cancelled.
Variants
Type 130
Prototype
Type 130A Bombay Mk I
Twin-engined medium bomber and troop transport aircraft.
Original designation Type 130 Mark II.
Type 137A
Proposed civil transport version,
Unbuilt.
Type 137B
Combi version of Type 137A, Unbuilt.
Type 144 Unbuilt development with retractable undercarriage proposed for Specification B.4/34 (won by Handley Page Harrow).
Specifications
Bombay Mk.I
Crew
3-4
Capacity
24 armed troops or 10 stretchers
Length
69 ft 3 in (21.11 m)
Wingspan
95 ft 9 in (29.18 m)
Height
19 ft 11 in (6.07 m)
Wing area
1,340 sq ft (124 m2)
Empty weight
13,800 lb (6,260 kg)
Gross weight
20,180 lb (9,153 kg)
Powerplant
2 × Bristol Pegasus XXII
9-cylinder air-cooled radial piston engines,
1,010 hp (750 kW) each
Propellers
3-bladed variable-pitch propellers
Performance
Maximum speed
192 mph (309 km/h, 167 kn)
Cruise speed
160 mph (260 km/h, 140 kn)
Ferry range
2,230 mi (3,590 km, 1,940 nmi) with overload fuel
Rate of climb
750 ft/min (3.8 m/s)
Wing loading
14.9 lb/sq ft (73 kg/m2)
Power/mass
0.10 hp/lb (0.16 kW/kg)
Armament
Guns
2 × 0.303 in (7.7 mm) Vickers K machine guns in both manually operated nose and tail turrets.
Bombs
2,000 lb (907 kg) as 8 × 250 lb (113 kg) bombs on under fuselage racks.
