Armstrong Whitworth Albemarle

The Armstrong Whitworth A.W.41 Albemarle was a British twin-engine transport aircraft that entered service during the Second World War.

The Albemarle was originally designed as a medium bomber, but never served in that role, instead being used 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.

Armstrong Whitworth Albemarle
Class Aircraft
Type Transport
Manufacturer Armstrong Whitworth
Production Period 1940 - 1945
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1940
Country Name Operational Year Retirement Year
Russia (USSR) View
United Kingdom - UK (Great Britain) 1940 1946 View
ManufacturerName Production From Production To Quantity
Armstrong Whitworth 1940 1945 600 View

The Albemarle was a mid-wing, cantilever monoplane with twin fins and rudders. The fuselage was built in three sections; the structure being unstressed plywood over a steel tube frame. The forward section used stainless steel tubing to reduce interference with magnetic compasses. It had a Lockheed hydraulically operated, retractable tricycle landing gear, with the main wheels retracting back into the engine nacelles, and the nose wheel retracting backwards into the front fuselage.

The two pilots side-by-side, a radio operator sat behind the pilots, and the navigator sat in the nose forward of the cockpit. The bomb aimer's sighting panel was incorporated into the crew hatch in the underside of the nose. In the rear fuselage were glazed panels, so a "fire controller" could coordinate the turrets against attackers. The dorsal turret was a Boulton-Paul design with four Browning machine guns. A fairing forward of the turret automatically retracted as the turret rotated to fire forwards. Fuel was in four tanks, and additional tanks could be carried in the bomb bay.

A 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.

The original bomber design required 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 operationally in the bomber role on two occasions. That was because the Albemarle was considered inferior to other aircraft already in service, such as the Vickers Wellington. All subsequent aircraft were built as transports, designated either "General Transport" (GT) or "Special Transport" (ST).

When used as a paratroop transport, 10 fully armed troops could be carried. The paratroopers were provided with a dropping hatch in the rear fuselage, and a large loading door in the fuselage side.

The entire production run of 600 Albemarles was assembled by A.W. Hawksley Ltd of Gloucester, a subsidiary of the Gloster Aircraft Company formed for the purpose of the construction of the Albemarle. Gloster was a part of the Hawker Siddeley group which included Armstrong Whitworth. Individual parts and sub-assemblies for the Albemarle were produced by about 1,000 subcontractors.

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
  •     Mk III - One prototype only.
  •     Mk IV - One prototype only.
  •     ST Mk V - 49
  •     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 the four gun turret replaced with hand operated twin-guns under a sliding hood. As a special transport, a loading door was fitted on the starboard side; the rear fuel tank was removed. 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 (1,186 kW) Bristol Hercules XI radial engines.

The Mk III and Mk IV Albemarles were development projects for testing different powerplants; the former used the Rolls-Royce Merlin III, and the latter used the 1,600 hp (1,190 kW) Wright Double Cyclone.

The first Albemarle (P1360) first flew on 20 March 1940 at Hamble Aerodrome, where it was assembled by Air Service Training, and was the first of two prototypes built by Armstrong Whitworth. To improve take-off, a wider span (77 from 67 ft) wing was fitted after the 8th aircraft. Plans for using it as a bomber were dropped due to delays in reaching service, it was not an improvement over current medium bombers (such as the Vickers Wellington) and it had obvious shortcomings compared to the four-engined heavy bombers about to enter service, but it was considered suitable for general reconnaissance.

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. On 9 February 1943, the first operational flight was a 296 Squadron Albemarle which dropped leaflets over Lisieux in Normandy. Albemarles took part in many of the major British airborne operations, such as the invasion of Sicily and of Normandy and the assault on Arnhem during Operation Market Garden.

In October 1942, the Soviet Air Force placed a contract for delivery of 200 Albemarles. No. 305 Ferry Training Unit was set up at RAF Errol near Dundee to train Soviet aircrews. During training, one aircraft was lost with no survivors. On 3 March 1943, the first Soviet AF Albemarle flew successfully from Scotland to Vnukovo airfield, followed by 11 more. Two aircraft were lost over the North Sea; one to German interceptors, and the other 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 favour of abundant American Douglas 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

The pinnacle of the aircraft's career was a series of operations for D-Day on 5 June 1944. 295 and 296 Squadrons sent aircraft to Normandy with the pathfinder force, and 295 Squadron claimed to be the first squadron to drop Allied troops during Operation Overlord. On 6 June 1944, four Albemarle squadrons and the operational training unit all sent aircraft during Operation Tonga; 296 Squadron used 19 aircraft to tow Airspeed Horsas, 295 Squadron towed 21 Horsas, although it lost six in transit, 570 Squadron sent 22 aircraft with ten towing gliders, and 42 OTU used four aircraft. For Operation Mallard on 7 June 1944, the squadrons towed 220 Horsas and 30 Hamilcars to Normandy.

On 17 September 1944, during Operation Market Garden at Arnhem, 54 Horsas and two Waco Hadrian gliders were towed to the Netherlands by 28 Albemarles of 296 and 297 squadrons; 45 aircraft were sent the following day towing gliders.

Of the 602 aircraft delivered, 17 were lost on operations, and 81 lost in accidents. The last Royal Air Force unit to operate the type was the Heavy Glider Conversion Unit, which replaced the Albemarles with Handley Page Halifaxes in February 1946, and the type was retired from operational units.

Role Transport, glider tug
Manufacturer A W Hawksley Ltd
Designer Armstrong Whitworth Aircraft
First flight 20 March 1940
Primary user RAF
Produced 1941–1945
Number built 602


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 ft (74.6 m)
  • Empty weight: 22,600 lb (10,270 kg)
  • Loaded weight: 35,500 lb (16,556 kg)
  • Max takeoff weight: 36,500 lb (16,590 kg)
  • Powerplant: 2 x 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, 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

End notes