Blackburn Cubaroo
| T.4 Cubaroo | |
|---|---|
| Role | Torpedo Bomber |
| Manufacturer | Blackburn Aircraft |
| Designer | F A Bumpus |
| First flight | 1924 |
| Status | Prototype |
| Number built | 2 |
The Blackburn T.4 Cubaroo was a prototype British biplane torpedo bomber of the 1920s. Built by Blackburn Aircraft and intended to carry a large 21 in (533 mm) torpedo, the Cubaroo was one of the largest single-engined aircraft of the world at the time of its first flight.
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[edit] Design and development
In 1921, the British Air Ministry issued Specification 8/21 to Blackburn for a Coastal Defence Torpedo Aeroplane, the resulting design was designated the T.4 Cubaroo. Due to the change change of policy in the Air Ministry to favour a twin-engined design a new sepcification was issued in 1922, the British Air Ministry drew up Specification 16/22, for a long-range torpedo bomber capable of carrying a 21 in (533 mm) torpedo (which was at the time thought capable of sinking the largest warship) over a range of 800 mi (1,300 km)[1]. Major F. A Bumpus, chief designer of Blackburn Aircraft submitted the design for the Blackburn T.4 Cubaroo, which was a large biplane powered by a single example of the new 1,000 hp (750 kW) Napier Cub engine. Avro also submitted a design against this specification, the Avro 557 Ava, which was a similarly large biplane, powered by two 600 hp (450 kW) Rolls-Royce Condor engines.
In order to carry the heavy (over 2,000 lb/907 kg) torpedo over a long range, the Cubaroo was massive. With a wingspan of 88 ft (27 m), it may have been the largest single-engine military aircraft in the world at the time[1], and was fitted with the most powerful aircraft engine available [2], the Napier Cub, which was an unusual X-type engine which weighed over a ton excluding radiators. The Cubaroo, with a mainly metal structure, had a deep fuselage to accommodate the Cub engine, and was fitted with folding, two-bay wings. In order to allow the torpedo to be carried, the Cubaroo was fitted with a main undercarriage comprising two sets of two wheels, with the torpedo being carried on a crutch between the two sets of wheels.
[edit] Operational history
The first prototype (with serial N166) flew in secrecy in the summer of 1924[1], proving to have good handling characteristics, with the engine not causing problems (the Cub had already been test flown in an Avro Aldershot test bed) [1]. It was then fitted with a metal, three-blade adjustable-pitch propeller and was delivered for testing at RAF Martlesham Heath, but was written off after its undercarriage collapsed on 2 February 1925. A second prototype flew in 1925, but the Air Ministry abandoned the requirement for a torpedo bomber to carry the 21 in (533 mm) torpedo, and lost interest in single-engine heavy bombers, so the second prototype Cubaroo was used as an engine test bed, flying with the experimental 1,100 hp (820 kW) Beardmore Simoon compression ignition engine [1].
[edit] Operators
- Royal Air Force operated aircraft for evaluation and as a test bed only.
[edit] Specifications (Cubaroo)
Data from The British Bomber since 1914 [1]
General characteristics
- Crew: Four - Pilot, Navigator, Bomb-aimer/gunner and midships gunner
- Length: 54 ft 0 in (16.46 m)
- Wingspan: 88 ft 0 in (26.83 m)
- Height: 19 ft 4 in (5.89 m)
- Empty weight: 9,632 lb (4,378 kg)
- Max. takeoff weight: 19,020 lb (8,645 kg)
- Powerplant: 1 × Napier Cub 16-cylinder water-cooled X-type engine, 1,000 hp (746 kW)
Performance
- Maximum speed: 100 kn (115 mph, 185 km/h)
- Range: 1,565 nmi (1,800 mi, 2,900 km)
- Endurance: 10 hours [3]
- Service ceiling: 11,800 ft (3,600 m) absolute
Armament
- 3 × .303 in (7.7 mm) Lewis Guns in midship gunners cockpit and at beam hatches
- 1 × 21 in (533 mm) naval torpedo
or
- 4 × 551 lb (250 kg) bombs
[edit] See also
- Aircraft of comparable role, configuration and era
[edit] References
- ^ a b c d e f Mason, Francis K (1994). The British Bomber since 1914. London: Putnam Aeronautical Books. ISBN 0 85177 861 5.
- ^ Lewis, Peter (1980). The British Bomber since 1914 (Third Edition ed.). London: Putnam. ISBN 0 370 30265 6.
- ^ Flight 1959
[edit] External links
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