Armstrong Whitworth Albemarle

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Albemarle

Type	medium bomber/transport
Manufacturer	Armstrong Whitworth Aircraft A W Hawksley Ltd
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.

1 Design and development
2 Operational history
3 Variants
4 Specifications (ST Mk I)
5 Operators
6 References
7 External links
8 Related content
9 External links

[edit] Design and development

The origin of the Albemarle lay in Air Ministry Specification B.38/18 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 first of two prototypes built by Armstrong Whitworth flew on March 20, 1940. 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 never operated in a bomber role. 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 and some were supplied to the Soviet Air Force.

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.

[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 (8 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 ten 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)

General characteristics

Crew: 4
Length: 59 ft 11 in (18.26 m)
Wingspan: 77 ft (23.47 m)
Height: 15 ft 7 in (4.75 m)
Wing area: 804 ft² (74.6 m²)
Empty weight: 22,600 lb (10,6250 kg)
Max takeoff weight: 36,500 lb (16,556 kg)
Powerplant: 2× Bristol Hercules XI radial engine, 1,590 hp (1,190 kW) each

Performance

Maximum speed: 265 mph at 10,500 ft (426 km/h at 3,200 m)
Range: 1,300 miles (2,092 km) ()
Service ceiling: 18,000 ft (5,486 m)

Armament

4 x .303 in (7.7 mm) machine guns in dorsal turret

[edit] Operators

Ten aircraft were exported to the Soviet Union.
United Kingdom, Royal Air Force
- No. 161 Squadron RAF
- No. 295 Squadron RAF
- No. 296 Squadron RAF
- No. 297 Squadron RAF
- No. 511 Squadron RAF
- No. 570 Squadron RAF