Avro 549 Aldershot
| Industry | Aerospace |
|---|---|
| Founded | 1910 |
| Founder | Alliott Verdon Roe |
| Headquarters | Manchester , United Kingdom |
| Products | Aircraft |
The Avro 549 Aldershot was a British heavy bomber aircraft featuring a single engine, constructed by Avro.
Development and design
Conceived to satisfy the British Specification 2/20 issued in 1920, the Aldershot was intended as a heavy bomber capable of long-range operations both day and night, powered by a Rolls-Royce Condor engine.[1] The specification demanded a range of 500 miles (800 km) and a bomb load of 2,000 lb (900 kg). Initially, this comprised one World War I-era 1,800 lb (820 kg) SN bomb but was later altered to either four externally carried 500 lb (230 kg) bombs or eight internally housed 250 lb (114 kg) bombs.[2][3] On 2 December 1920, the Air Ministry awarded Avro a contract for two prototypes designated Aldershot I, competing against the de Havilland Derby.[1]
The maiden flight of the first prototype took place at Hamble Aerodrome, near Southampton, in October 1921.[4] Testing revealed the need for improved directional stability, leading to an extension of the fuselage by six feet (2 m). This lengthened version was presented at the RAF Display held at Hendon on 24 June. The second prototype flew in July featuring this extended fuselage alongside a redesigned undercarriage.[4][5]
The initial prototype was later adapted as a test platform for the water-cooled Napier Cub engine, reclassified as the Aldershot II and flying in this configuration on 15 December 1922.[6] Subsequently, it served to evaluate the slow-turning inline Beardmore Typhoon I engine producing 850 hp (630 kW), with its first flight in this setup occurring on 10 January 1927.[7]
Structurally, the Aldershot was a three-bay biplane featuring a fuselage framework made from steel, covered with plywood and fabric, while its wings were constructed from wood. The pilot and navigator occupied side-by-side positions in a cockpit situated behind the upper wing's trailing edge. Additional space inside the fuselage accommodated the navigator—also serving as bomb-aimer—in a cabin equipped with four circular windows on each side. A separate cockpit behind the pilot housed a gunner armed with a Lewis gun mounted on a Scarff ring. Another Lewis gun could be installed on a ventral mounting within the cabin. There was also provision for a fixed forward-firing Vickers machine gun operated by the pilot; however, this armament was seldom installed.[4] Bombs were carried in a bay located ahead of the cabin capable of housing eight 250 lb (114 kg) bombs internally, with larger ordnance mounted externally beneath the fuselage.[8]
The design of the Aldershot also served as the foundation for the Avro Andover transport aircraft which retained its wings, tail assembly, and powerplant but featured an entirely new fuselage.[9]
Operational history
During comparative trials with the de Havilland Derby, the Aldershot demonstrated clear superiority,[10] largely due to its mixed-material construction, which resulted in a weight approximately 800 lb (360 kg) less than the entirely wooden Derby. The Derby lacked internal bomb-carrying capability and did not feature any ventral armament options.[11]
On 26 January 1923, the Air Ministry placed an order for 15 units designated as Aldershot III.[12] The sole user of this aircraft was No. 99 Squadron RAF, which was re-established on 1 April 1924,[13] and began receiving Aldershots from July of that year.[9] Primarily deployed for nocturnal flights, the Aldershot was occasionally used in daytime bombing drills. Unlike other heavy bombers in RAF service, it featured a distinctive all-silver paint finish rather than the standard dark-green NIVO camouflage typically applied for night missions.[14] By 1925, the Air Ministry had concluded that multi-engine configurations were preferable for heavy bombers. Consequently, No. 99 Squadron began transitioning to the twin-engine Handley Page Hyderabad starting January 1926, fully phasing out the Aldershot by March of the same year.[9]
Variants
- Avro 549 Aldershot I
- Prototype model; two units constructed.
- Avro 549A Aldershot II
- Modified first prototype equipped with a 1,000 hp (746 kW) Napier Cub engine.
- Avro 549B Aldershot III
- Production variant with 15 units built. One example was altered to incorporate metal wings and re-designated as Avro 549M.[15]
Photograph of Avro 549C Aldershot IV from L'Air, February 15, 1927 - Avro 549C Aldershot IV
- First prototype adapted to use a Beardmore Typhoon engine.
Operators
Specifications (Aldershot III)
See also
Notes
- ↑ 1.0 1.1 Jarrett 1993, p.9.
- ↑ Mason 1994, p.136.
- ↑ Sharpe, Michael. Biplanes, Triplanes, and Seaplanes. London, England: Friedman/Fairfax Books, 2000. ISBN 1-58663-300-7.
- ↑ 4.0 4.1 4.2 Mason 1994, p.137.
- ↑ Jarrett 1993, p.11.
- ↑ Jackson 1990, p.195.
- ↑ Jackson 1990, p.197.
- ↑ Jarrett 1993, pp.9–10.
- ↑ 9.0 9.1 9.2 Thetford 1993, p.10.
- ↑ Thetford 1993, p.7.
- ↑ Mason 1994, pp.138–139.
- ↑ Thetford 1993, p.8.
- ↑ Lewis 1959, p.49.
- ↑ Thetford 1993, p.8–9.
- ↑ Mason 1994, p.138.
References
- Jackson, A.J. (1990). Avro Aircraft since 1908 (Second ed.). London: Putnam. ISBN 0-85177-834-8.
- Lewis, Peter (1959). Squadron Histories: R.F.C, R.N.A.S and R.A.F. 1912–59. London: Putnam.
- Mason, Francis K. (1994). The British Bomber since 1914. London: Putnam. ISBN 0-85177-861-5.
- Jarrett, Philip (March 1993). "By Day and By Night: Part 10 Avro Aldershot Development History". Aeroplane Monthly. Vol. 24, no. 3. London: IPC. pp. 8–13, 28. ISSN 0143-7240.
- Thetford, Owen (April 1993). "By Day and By Night: Part 11 Avro Aldershot Service History". Aeroplane Monthly. Vol. 24, no. 4. London: IPC. pp. 6–10. ISSN 0143-7240.
- The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985). Orbis Publishing.
External links
- Avro Aldershot – British Aircraft Directory