| C.A.15C | |
|---|---|
 | |
| Blackburn CA 15C monoplane | |
| Role | experimental biplane and monoplane civil passenger aircraft |
| National origin | United Kingdom |
| Manufacturer | Blackburn Aeroplane and Motor Co. Ltd |
| Designer | B.A.Duncan |
| First flight | 10 June 1932 |
| Number built | 2 |
The Blackburn C.A.15C Monoplane and Biplane were a pair of British aircraft intended to be as similar as possible apart from their wing arrangement. Tests in 1933 did not favour either design conclusively.
Though best known for military aircraft, Blackburn did investigate the commercial market. In particular they designed, but did not build, the C.A.15A (C.A. being Blackburn's designation for commercial aircraft), an 11-seat passenger tri-motor monoplane. This had the central engine mounted above and clear of the high wing, the other two engines suspended below the wings. [1] Unusually, they intended to offer a biplane equivalent, an option made easy by the monoplane's wing-engine configuration. They also investigated a slightly smaller version, the C.A.15B. [2] These designs suggested to the Air Ministry that two otherwise identical aircraft could be built in monoplane and biplane versions to settle the constant dispute over which of these two configurations was the superior. Blackburn received a contract to build them.
The two C.A.15Cs were [1] [3] all-metal aircraft apart from the fabric-covered wings and tail surfaces. The fuselage, cabin and empennage were the same in both versions. The tailplane was braced and the fin and rudder rather angular and flat-topped, the rudder horn-balanced. Because the Air Ministry envisaged the aircraft going to Imperial Airways after the trials, the cabins were fully fitted out for ten passengers, with two compartments containing six and four seats placed singly on either side of a central aisle. Warm air heating was fed from the engines. Between the enclosed cockpit for the two crew and the passenger cabins was a baggage compartment. [1]
The wings were built in standard Blackburn fashion with steel spars and duralumin ribs. The biplane was of single-bay construction with equal-span, un-staggered wings. The upper wing was well clear of the fuselage. The monoplane had a high, braced wing. Total wing areas were similar, that of the monoplane some 3% greater. The desire to make the two aircraft as similar as possible somewhat penalised the monoplane because the divided undercarriage that fitted easily on the biplane's lower wing required some elaborate bracing on the monoplane. [1]
The two versions used the same engines, a pair of 400 hp (300 kW) Armstrong Siddeley Jaguar IVC radials driving wooden two-blade propellers. They were, however, mounted differently, unlike the proposed C.A.15A and C.A.15B. The monoplane had engines embedded in the wings, while those in the biplane were mounted between the wings. [1]
The biplane G-ABKW flew first on 10 June 1932 and the monoplane G-ABKV on 4 October 1932. The biplane turned out to be heavy to fly and with unreliable brakes making taxying difficult. Tailwheels were quite new at the time and the aircraft was troubled by shimmy. The monoplane posed fewer problems. [1]
The two machines went to RAF Martlesham Heath in January 1933 for comparative trials. Despite the hopes, the trials were not conclusive. At the same all-up weight, the monoplane was faster and had a better rate of climb, but having an empty weight about 10% greater, it could not carry so great a payload. [1]
The proposed post-trial move to Imperial Airways did not happen for they were already re-equipping, so the biplane was immediately broken up. The monoplane did do useful service at the Royal Aircraft Establishment at Farnborough in the development of automatic pilots and in wireless experiments in RAF colours as K4241. It then served a few months as an RAF taxi before being scrapped at the end of 1937. [1]
Data from Jackson 1968, pp. 307–8
General characteristics
| Monoplane | Biplane | |
|---|---|---|
| Length | 55 ft 3 in (16.84 m) | 55 ft 0 in (16.76 m) |
| Span | 86 ft 0 in (26.21 m) | 64 ft 0 in (19.5 m) |
| Height | 16 ft 9 in (5.10 m) | 16 ft 0 in (4.88 m) |
| Wing area | 1,068 ft2 (99.22 m2) | 1,037 ft2 (96.34 m2) |
| Empty weight | 8,818 lb (4,000 kg) | 7,931 lb (3,597 kg) |
| All-up weight | 13,074 lb (5,930 kg) | 12,150 lb (5,511 kg) |
| Maximum speed | 128 mph (206 km/h) | 118 mph (190 km/h) |
| Cruising speed | 110 mph (177 km/h) | 110 mph (177 km/h) |
| Initial climb rate | 665 ft/min (3.38 m/s) | 535 ft/min (2.72 m/s) |
| Service ceiling | 13,500 ft (4,115 m) | 9,000 ft (2,743 m) |
| Range | 350 miles (563 km) | 350 miles (563 km) |
Blackburn Aircraft Limited was a British aircraft manufacturer that concentrated mainly on naval and maritime aircraft during the first part of the 20th century.
The Blackburn Iris was a British three-engined biplane flying boat of the 1920s. Although only five Irises were built, it was used as a long-range maritime reconnaissance aircraft by the Royal Air Force, where it equipped a squadron for four years, being used to carry out a number of notable long-distance flights. The final version of the Iris, the Iris Mark V was developed into the aircraft that replaced it in Squadron service, the Blackburn Perth.
The Armstrong Whitworth AW.15 Atalanta was a four-engine airliner designed and produced by the British aircraft manufacturer Sir W.G. Armstrong Whitworth Aircraft Limited at Coventry.
The de Havilland Moths were a series of light aircraft, sports planes, and military trainers designed by Geoffrey de Havilland. In the late 1920s and 1930s, they were the most common civilian aircraft flying in Britain, and during that time every light aircraft flying in the UK was commonly referred to as a Moth, regardless if it was de Havilland-built or not.
The Supermarine Air Yacht was a British luxury passenger-carrying flying boat. It was designed by Supermarine's chief designer R. J. Mitchell and built in Woolston, Southampton in 1929. It was commissioned by the brewing magnate Ernest Guinness, and was the first British flying yacht built to the order of a private owner. Only one machine was built.
The Saro Cloud was a British passenger amphibian flying boat designed and built by Saunders-Roe as the A.19. It was later produced as the A.29 for the Royal Air Force for pilot and navigator training.
The Blackburn F.1 Turcock was a British single-seat single-engine biplane fighter built in 1927. Designed to be produced in several variants, only one was completed.
The Blackburn R.2 Airedale was a single-engine three-seat monoplane deck-landing aircraft for land and sea reconnaissance, built in the UK in 1924. Only two were built.
The Blackburn T.R.1 Sprat was a British single-engine two-seat biplane trainer, built in 1926 for advanced training, deck-landing and seaplane experience. Just one was built.
The Blackburn 2F.1 Nautilus was a British single-engine two-seat biplane spotter/fighter built in 1929. Only one was completed.
The Blackburn B.T.1 Beagle was a British single-engine, two-seat biplane bomber/torpedo aircraft from 1928. Designed to Air Ministry specifications which led to no contracts for any manufacturer, only one Beagle was built.
The Blackburn Second Monoplane was strongly influenced by the French Antoinette and was much more successful than Robert Blackburn's first aircraft. The lone aircraft was built in Leeds, UK in 1910.
The Blackburn White Falcon was a two-seat single-engine monoplane built as a personal transport for Blackburn's test pilot during the First World War. Only one was built.
The Vickers Viastra was an all-metal 12-seat passenger high-wing monoplane, with variants powered by one, two and three engines. Two twin-engined Viastras operated commercially in Australia from 1931-6; another served as a Royal transport.
The de Havilland DH.72 was a large British three-engined biplane bomber, designed as a Vickers Virginia replacement. It did not go into production.
The Fairey G.4/31 was a British single-engined, two-seat biplane contender for an Air Ministry specification for a multi-role or general purpose aircraft. Unsuccessful, only one was built.
The Parnall Pixie was a low powered British single-seat monoplane light aircraft originally designed to compete in the Lympne, UK trials for motor-gliders in 1923, where it was flown successfully by Norman Macmillan. It had two sets of wings, one for cross-country flights and the other for speed; it later appeared as a biplane which could be converted into a monoplane.
The Parnall Perch was a single-engined, side-by-side-seat aircraft designed in the UK to meet an Air Ministry specification for a general-purpose trainer. No contract on this specification were awarded and only one Perch was built.
The Blackburn Type E was a development of the earlier Blackburn Mercury single-engined monoplanes, but was innovative in its use of steel tubing to construct the fuselage. It was built during 1912 to compete in the Military Aeroplane Trials. A single-seat version flew, but the military two-seater did not.
The Junkers J 15 was an all-metal monoplane built in Germany in 1920 to explore the design parameters of small single-engined passenger transports. In particular, it could fly in either high or low wing configurations. It led to the Junkers J 16 light airliner.
 | Wikimedia Commons has media related to Blackburn C.A.15C . |