Handley Page H.P.31 Harrow
H.P.31 Harrow | |
---|---|
First prototype in 1927 with new cowling | |
Role | Bomber, torpedo bomber and reconnaissance aircraft |
National origin | United Kingdom |
Manufacturer | Handley Page |
First flight | 24 April 1926 |
Retired | 1928 |
Number built | 2 |
The Handley Page H.P.31 was a two-seat single-engined biplane built to a British specification for a carrier-based torpedo bomber and reconnaissance aircraft. After trials, the Blackburn Ripon was preferred, though the Harrow played a significant role in the development of automatic slots.
Development
In early 1924 the Air Ministry specification 21/23 was issued, calling for a two-seat replacement for the Blackburn Dart capable of acting as a torpedo or conventional bomber over short ranges as well as having 12-hour reconnaissance capability. The Harrow, initially known as the Type E but retrospectively as the H.P.31 when the company introduced numerical designations in 1924, was Handley Page's tender. They were successful, receiving an order to build two prototypes.[1]
The Harrow was essentially a single-bay biplane, though there was an additional pair of interplane struts at the extremities of the centre section. The wings had the same span and constant chord and neither sweep nor stagger. Both upper and lower wings had outboard ailerons and inboard flaps, the latter ending at the centre section. Both wings also had
It was powered by a single water-cooled Napier Lion engine, initially a 470 hp (350 kW) mark V, mounted as low in the nose as airscrew ground clearance allowed so that the top of the fuselage could fall away in front of the cockpit for the best views during high-incidence carrier landings. There was a front-mounted radiator immediately beneath the propeller shaft. The pilot sat below the upper wing just behind the rear spar and with a cutout for visibility. The observer/gunner's position was close behind the pilot for ease of communication, since he had to do the work of navigation on long flights away from the carrier that had been traditionally assigned to a third crew member. Behind them the fabric-covered fuselage carried a conventional tail with horn-balanced control surfaces, though the incidence of the whole tailplane could also be adjusted.[1]
The Harrow had to have a clear space below the fuselage to allow torpedo dropping. The main legs were attached to the front spar at the ends of the centre section, and pairs of bracing struts ran from the stub axles to the lower fuselage longerons. Snap link hooks were fitted to the inner ends of the axles to engage with the longitudinal arrester wires of the time. The specification required that the land undercarriage could be replaced rapidly with floats. These were long, single stepped and fitted with water rudders, built by Short Brothers.[1]
The first flight of the Harrow was made by
During the late summer of 1927 the second prototype had been involved in continuing the series of Air Ministry tests of slats previously conducted on the Hendon III. It used the latest version of automatic wingtip slats and was hailed as a great success and a sure defence against the inadvertent spin. It was retired at the end of September.[1]
Specifications (Harrow II, landplane)
Data from Barnes & James 1987, pp. 368
General characteristics
- Crew: two
- Length: 34 ft 10 in (10.62 m)
- Wingspan: 46 ft 0 in (14.02 m)
- Wing area: 591 sq ft (54.9 m2)
- Empty weight: 4,125 lb (1,870 kg)
- Gross weight: 7,310 lb (3,316 kg)
- Powerplant: 1 × Napier Lion XIA 12-cylinder W configuration (broad arrow) water-cooled , 530 hp (395 kW)
Performance
- Maximum speed: 126 mph (202 km/h, 109 kn)
- Range: 450 mi (725 km, 390 nmi)
- Service ceiling: 15,300 ft (4,730 m)
Armament
- 1×0.303 in (7.7 mm) Vickers machine gun fixed forward firing through airscrew
- 1×0.303 in (7.7 mm) Lewis machine gun on Scarff ring
- 1×18 in (457 mm) torpedo or 3×520lb (236 kg) bombs
References
Bibliography
- Barnes, C.H.; James, D. N. (1987). Handley Page Aircraft since 1907. London: Putnam Publishing. ISBN 0-85177-803-8.