Designed for mixed composite steel and wood construction, the prototype flew in 1939, but was destroyed in a crash before the first flight of the second prototype on 20 March 1940. The Albemarle's form of structure enabled wide use of sub-contracting, even to small companies outside the aircraft industry (one source mentions almost 1,000 sub-contractors), and an additional bonus came from conservation of light alloy and other strategic materials. The tricycle landing gear was of Lockheed design and rare on British aircraft.

The first 32 aircraft were built as bombers, although not used as such, and there was considerable delay in establishing production lines. The first three production Albemarles left the factory in December 1941, by which time the decision had been made to adapt the aircraft as a glider tug and airborne forces transport.

An Armstrong Whitworth A.W.41 Albemarle Mk I of the Royal Air Force. Generally an unpopular aircraft with both crews and passengers

Deliveries to the RAF began in January 1943 when No. 295 Squadron received its first aircraft. The type was blooded with Nos. 296 and 297 Squadrons, part of No. 38 Wing operating from North Africa, in the invasion of Sicily in July 1943. On D-Day (6 June 1944) six No. 295 Squadron Albemarles, operating from Harwell, served as pathfinders for the 6th Airborne Division, dropping paratroops from the 22nd Independent Parachute Company over Normandy.

In the glider tug role they were fitted with Malcom Glider Towing gear. Four squadrons of Albemarles were used to tow Airspeed Horsas to France in support of ground operations, while in September 1944 two of No. 38 Group's squadrons participated in the ill-fated Arnhem operation, towing gliders carrying troops of the 1st Airborne Division. But probably the most abiding memory of the aircraft is the pall of smoke in which they taxied on return, caused by the overheating of the engines having to supply high power at low speed.

Production of the Albemarle, apart from the prototypes, was undertaken by A.W. Hawksley Ltd, part of the Hawker Siddeley Group. Production came to an end in December 1944 when 600 Albemarles had been built. Original orders had covered 1,080, but 478 from the second production batch were cancelled. Deliveries to the RAF consisted of 380 transport versions, (99 Mk I, 99 Mk 11, 49 Mk V and 133 Mk VI) and 186 glider tugs (69 Mk I and 117 Mk VI). Additional to these were the original 32 bombers which were subsequently converted to transports. Ten Albemarles were delivered to the Russian air force from RAF stocks and were used as transports.

All Albemarles used the 1,590 hp (1186 kW) Bristol Hercules XI 14-cylinder radial engine, apart from a single Mk IV prototype with Wright Double Cyclones, and differences in the marks were primarily in equipment. The original bomber versions were fitted with a four-gun Boulton Paul dorsal turret, but weight considerations dictated the removal of this in the transports and glider tugs which, instead, mounted twin Vickers 'K' hand-operated guns.

While the Albemarle was not a particularly significant aircraft, it did perform a useful role, releasing other types for more vital tasks. In addition, because of its method of construction and the materials used, production did not unduly disturb the flow of more important types at a time when these were vital to the United Kingdom's survival. As a "Special Transport" it had also been used to carry mail and equipment for the RAF from Great Britain to Gibraltar, North Africa and Malta.

Variants

Albemarle Mk I Series I - Aircraft built as reconnaissance bombers, powered by two 1,590 hp (1186 kW) Bristol Hercules XI 14-cylinder radial engines, which became standard for all types. The crew consisted of two pilots, navigator/bomb-aimer, radio operator and two gunners. Armament consisted of four 7.7 mm (0.303 in) Browning machine-guns in a Boulton Paul dorsal turret and two 7.7 mm (0.303 in) Vickers "K" machine-guns in a powered ventral turret. First deliveries to the RAF were on 23 October 1941. The aircraft was equipped with a bomb bay. All these aircraft were later converted to the transport/glider tug standard.

Albemarle S.T. I Series I - A Special Transport version with all the bombing equipment and the rear fuselage fuel tank removed. The four gun Boulton Paul dorsal turret was replaced with a hand operated installation covered by a sliding hood and containing two 7.7 mm (0.303 in) Vickers "K" machine-guns. The two gun ventral turret was removed and a freight loading door was fitted in the starboard side of the centre fuselage. The bomb bay doors were sealed over.
 

Albemarle Mk I Series II - Similar to the Albemarle Mk I Series I but with Malcolm Glider Towing gear. The bomb bay was converted over to accommodate three addition fuel tanks.

Albemarle S.T. I Series II - A Special Transport version equipped with Malcolm Glider Towing gear.

Albemarle Mk II - A Paratroop-carrier and Glider Tug. Ten paratroops carried forward of the large drooping hole in the floor of rear fuselage with rails on each side of the fuselage for parachute static drops. Tubular guard under tailplane to prevent free drops from fowling the elevators. Also fitted with Malcolm Glider Towing gear. First deliveries to the RAF in January 1943.

Albemarle Mk IV - A single prototype only consisting of a single Mk I fitted with two 1,600 hp Wright GR-2600-A5B Cyclone 14 air-cooled radial engines.

Albemarle Mk V - Similar to the Mk II but with the addition of fuel jettisoning equipment.

Albemarle Mk VI Series I - Same as the Mk V plus a large freight loading door in the fuselage to facilitate the loading of bulky materials which may be required to be carried on paratroop operations.

Albemarle Mk VI Series II - Same as the Mk VI Series I but with the addition of special radio equipment for glider towing. The upper gun position was deleted leaving the aircraft unarmed. 

Specifications (Armstrong Whitworth A.W.41 Albermarle Mk VI)

Type: Four Seat General Purpose Transport, Paratroop Carrier & Glider Tug

Accommodation/Crew: (Mk I Series I) Two Pilots, Navigator/Bomb-aimer, Radio Operater and two gunners. (Armed Transport version) Two Pilots, Navigator, Radio Operator/Gunner

Design: Armstrong Whitworth Aircraft Limited under Chief Designer John Lloyd based on an original design by the Bristol Aeroplane Company

Manufacturer: Armstrong Whitworth Aircraft Limited produced the prototypes but A.W. Hawksley Limited (Division of the Hawker Siddeley Group) produced all production aircraft at its Gloucester Plant. The Hawker Siddeley Aircraft Company owned the Armstrong Siddeley Development Company which had controlling interest in Armstrong Whitworth Aircraft Limited.

Powerplant: Two 1,590 hp (1186 kW) Bristol Hercules XI 14-cylinder air-cooled sleeve-valve radial engines driving a three-bladed D.H. Hydromatic fully-feathering airscrew. The engines are mounted in Briston interchangeable power-units, to which the oil-cooler installation and accessory system peculiar to the airframe have been added. There are four oil tanks located in each nacelle.

Performance: Maximum speed 265 mph (426 km/h) at 10,550 ft (3200 m); cruising speed 170 mph (274 km/h); service ceiling 18,000 ft (5485 m); initial climb rate of 980 ft (299 m) per minute.

Range: 1,341 miles (2160 km) on internal fuel, but could be extended by the addition of three auxiliary fuel tanks mounted in the bomb bay.

Weight: Empty 22,600 lbs (10260 kg) with a maximum overload take-off weight of 36,500 lbs (16570 kg).

Dimensions: Span 77 ft 7 in (23.47 m); length 59 ft 11 in (18.26 m); height 15 ft 7 in (4.75 m); wing area 803.5 sq ft (74.65 sq m).

Armament: (Mk I Series I - Bomber) Four 7.7 mm (0.303 in) Browning machine-guns in a Boulton Paul dorsal turret and two 7.7 mm (0.303 in) Vickers "K" machine-guns in a powered ventral turret. (S.T. I Series I) A "Special Transport" version with only two 7.7 mm (0.303 in) Vickers "K" machine-guns in a manally operated dorsal installation. This became the "standard" armament for the transport versions although some aircraft were unarmed. (Mk VI Series II) The dorsal position was eliminated leaving this version unarmed.

Variants: Mk I Series I (recon/bomber), Mk I Series II (glider tug), S.T. Mk I Series I (special transport), S.T. Mk I Series II (special transport), Mk II (paratroop/glider tug), Mk IV (single prototype), Mk V (paratroop/glider tug), Mk VI Series I (paratroop/transport), Mk VI Series II (paratroop/glider-tug).

Equipment/Avionics: Malcom Glider Towing gear equipped aircraft used special radio equipment.

History: First flight (1st prototype) 1939 but was soon destroyed in a crash; first flight (2nd prototype) 20 March 1940; first delivery (Mk I Series I) 23 October 1941; end production December 1944.

Operators: Great Britain (RAF Transport Command), Soviet Union (10 aircraft).