Armstrong Whitworth Albemarle
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| Albemarle | |
|---|---|
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| Type | medium bomber/transport |
| Manufacturer | A W Hawksley Ltd |
| Designed by | Armstrong Whitworth Aircraft |
| Maiden flight | 20 March 1940 |
| Primary user | RAF |
| Number built | 600 |
The Armstrong Whitworth A.W.41 Albemarle was a British twin-engined transport aircraft that entered service during the Second World War. Originally designed as a medium bomber, the Albemarle never served in that role, instead being converted for general and special transport duties, paratroop transport and glider towing including significant actions such as Normandy and the assault on Arnhem during Operation Market Garden.
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[edit] Design and development
The origin of the Albemarle lay in Air Ministry Specification B.18/38 which required a twin-engined medium bomber of wood and metal construction that could be built by manufacturers outside the aircraft industry. Large parts of the aircraft were therefore constructed in steel to conserve aluminium. This had a negative effect on performance. The entire production run of 600 Albemarles were assembled by A.W. Hawkesley Ltd of Gloucester; the actual parts having been produced by some 1,000 subcontractors.[1].
The Albermarle was a mid-wing, cantilever monoplane with a steel tube framework fuselage built in three sections. The tail unit had twin fins and rudders and it had a hydraulically-operated, retractable tricycle landing gear, with the main wheels retracting back into the engine nacelles and the nose wheel raised backwards into the front fuselage. It had accommodation for a navigator in the nose and two pilots side-by-side and a radio operator in the forward fuselage. When used as a paratroop transport, 10 fully armed troops could be carried. The paratroopers had a dropping hole in the rear fuselage and a large loading door in the fuselage side.[2]
The first of two prototypes built by Armstrong Whitworth flew on 20 March 1940[3]. The original bomber design required for a crew of six including two gunners; one in a four-gun dorsal turret and one in a twin-gun ventral turret. However only the first 32 aircraft, the Mk I Series I, were produced in this configuration and they were only used in anger in the bomber role on two occasions.[4] This was because the Albermarle was considered inferior to other aircraft already in service, such as the Vickers Wellington.[4] All subsequent aircraft were built as transports, designated either "General Transport" (GT) or "Special Transport" (ST).
The most notable design feature of the Albemarle was its undercarriage which included a retractable nose-wheel (in addition to a semi-concealed "bumper" tail-wheel). It was the first British-built aircraft with this configuration to enter service with the Royal Air Force.
[edit] Operational history
The first squadron to operate the Albemarle was No. 295 at RAF Harwell in January 1943. Other squadrons to be equipped with the Albemarle were No. 296, No. 297 and No. 570. Other RAF squadrons operated small numbers of the aircraft. Albemarles took part in many of the major British airborne operations such as the invasions of Sicily and Normandy and the assault on Arnhem during Operation Market Garden.
In October 1942, the Soviet Air Force secured a contract for delivery of 200 Albemarles. No 503 Ferry Training Unit was set up at RAF Errol near Dundee to train Soviet aircrews.[4] During training, one aircraft was lost with no survivors. The first Albemarle from Scotland flew successfully to Vnukovo airfield on 3 March 1943,[4] followed by 11 more. Two planes were lost over the North Sea (one to German interceptors, one unaccounted for).
Tests of the surviving Albemarles revealed their weaknesses as transports (notably the cramped interior) and numerous technical flaws; in May 1943, the Soviet government put further deliveries on hold and eventually cancelled them in favor of abundant American C-47 Skytrains. The Soviet camp at Errol field continued until April 1944, apparently the Soviet command hoped to secure de Havilland Mosquito deliveries. Twelve Soviet Albemarles served for about two years; at least two were lost in accidents. Surviving aircraft were retired at the end of 1945.
[edit] Variants
Over the course of its production life, a number of variants of the Albemarle were built:
- ST Mk I - 99 aircraft
- GT Mk I - 69
- ST Mk II - 99
- ST Mk V - 49
- Mk IV - One prototype only.
- ST Mk VI - 133
- GT Mk VI - 117
Most Marks were divided into "Series" to distinguish differences in equipment. The ST Mk I Series 1 (eight aircraft) had only a twin gun dorsal turret. The 14 ST Mk I Series 2 aircraft were equipped with gear for towing gliders. The Mk II could carry 10 paratroops and the Mk V was essentially the same but with a fuel jettison capability. All production Albemarles were powered by a pair of 1,590 hp Bristol Hercules XI radial engines.
The Mk III and Mk IV Albemarles were development projects testing different powerplants; the former using the Rolls-Royce Merlin III and the latter with the 1,600 hp (1,190 kW) Wright Double Cyclone.
[edit] Specifications (ST Mk.I)
Data from The Unloved Albermarle
General characteristics
- Crew: 4
- Capacity: 10 paratroopers in ST
- Payload: 4,000 lb freight (1820 kg)
- Length: 59 ft 11 in (18.26 m)
- Wingspan: 77 ft 0 in (23.47 m)
- Height: 15 ft 7 in (4.75 m)
- Wing area: 804 ft² (74.6 m²)
- Empty weight: 22,600 lb[5] (10,270 kg)
- Loaded weight: 35,500 lb (16,556 kg)
- Max takeoff weight: 36,500 lb (16,590 kg)
- Powerplant: 2× Bristol Hercules XI radial engine, 1,590 hp (1,190 kW) each
Performance
- Maximum speed: 230 knots (265 mph, 426 km/h) at 10,500 ft (3,200 m)
- Cruise speed: 148 knots (170 mph, 274 km/h)
- Stall speed: 61 knots (70 mph,[6] 113 km/h)
- Range: 1,300 miles (2,092 km)
- Service ceiling 18,000 ft (5,486 m)
- Rate of climb: 980 ft/min (5.0 m/s)
Armament
- 4 x .303 in (7.7 mm) machine guns in dorsal turret.
- 2 x .303 in machine guns in ventral turret (first prototype only)
- Internal bomb bay for 4,500 lb bombs
[edit] Operators
- Twelve aircraft were exported to the Soviet Union (two more lost in transit).
- transport arm of 1st Air Division, later 10th Guards Air division (to 1944); naval air units until retirement in 1945
- Royal Air Force
- No. 161 Squadron RAF
- No. 271 Squadron RAF
- No. 279 Squadron RAF
- No. 295 Squadron RAF
- No. 296 Squadron RAF
- No. 297 Squadron RAF
- No. 502 Squadron RAF
- No. 511 Squadron RAF
- No. 521 Squadron RAF
- No. 570 Squadron RAF
[edit] See also
Related lists
[edit] References
[edit] Notes
- ^ British Aircraft of WWII Retrieved: 15 March 2007.
- ^ Bridgman, Leonard. Jane's Fighting Aircraft of World War II. New York: Crescent Books, 1988. ISBN 0-517-67964-7.
- ^ Mason 1994, p. 335-337.
- ^ a b c d Williams 1989
- ^ Albemarle
- ^ Air Transport Auxiliary Ferry Pilots Notes. Elvington, Yorks: Yorkshire Air Museum, Reproduction 1996. ISBN 0-9512379-8-5.
[edit] Bibliography
- Bowyer, Michael J.F. Aircraft for the Royal Air Force: The "Griffon" Spitfire, The Albemarle Bomber and the Shetland Flying-Boat. London: Faber & Faber, 1980. ISBN 0-571-11515-2.
- Mason, Francis K. The British Bomber since 1914. London: Putnam Aeronautical Books. 1994. ISBN 0-85177-861-5.
- Morgan, Eric B. "Albemarle". Twentyfirst Profile, Volume 1, No. 11. New Milton, Hants, UK: 21th Profile Ltd. ISBN 0-961-82100-4.
- Williams, Ray. "The Unloved Albermarle". Air Enthusiast, May-August 1989. p. 29-42. ISSN 0143-5450.
[edit] External links
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