Armstrong Whitworth A.W.41 Albemarle - Aircraft of World War II

Hobilar · 11-09-2007, 05:52 AM

The Albemarle originated as the Bristol type 155 design to meet an Air Ministry requirement of 1938 for a twin engined bomber. Production was transferred to Armstrong Whitworth when it became clear that the latter had spare design and production capacity. A design team under the supervision of John Lloyd was set the difficult task of taking over another company's creation and adapting it to meet a revised Ministry requirement for a reconnaissance bomber.

The revised Armstrong Whitworth design was very different from the original Bristol concept in detail and construction. The airframe was of mixed composite steel and wood (thereby reducing demand for strategic light alloys). Most of the components were produced by subcontractors (one source mentions almost 1,000 sub contractors even to small companies outside the aircraft industry), with final assembly being made by A.W. Hawksley Ltd.

The Albemarle was the first operational aircraft in RAF service to have a tricycle undercarriage. This was of Lockheed design.

Hobilar · 11-09-2007, 05:54 AM

The first of two prototypes flew on 20 March 1940 but proved to be a poor performer as a result of its great structural weight. This machine was destroyed in a crash before the flight of the second prototype in January 1941. The first three aircraft (after considerable delay in establishing production lines) emerged from the factory in December 1941.

The first 32 production aircraft were built as bombers, although they were not used as such. These aircraft were installed with a four-gun Boulton Paul dorsal turret, but weight considerations dictated the removal of this in later aircraft, being replaced by a pair of Vickers 'K' hand operated machine guns. Deliveries to the Royal Air Force began in January 1943 when No.295 Squadron received its first aircraft. By this time the decision had been made to adapt the type as a glider tug and airborne forces transport.

The Albemarle was blooded by No.296 and 297 Squadrons RAF (part of No.38 Wing) operating from North Africa, in the invasion of Sicily in July 1943. On D-Day (6 June 1944) six of No.295 Squadron's Albemarle aircraft. Operating from Harwell, served as pathfinders for the 6th Airborne Division's paratrooper drop over Normandy. In addition four squadrons of the type acted as glider tugs. In September 1944 two Squadrons of Albemarles towed gliders carrying troops of the 1st Airborne Division as a part of the Arnhem operation.

Hobilar · 11-09-2007, 05:57 AM

Production ceased in December 1944 after the completion of 602 aircraft. An order for a second batch of 478 machines was cancelled. Albemarle deliveries to the RAF consisted of 310 transport aircraft (78 Albemarle ST Mk.I, 99 Albemarle ST Mk.II and 133 Albemarle ST Mk.VI) and 246 glider tugs (80 Albemarle GT MkI, one Albemarle GT MkII, 49 Albemarle GT Mk V, and 117 Albemarle Mk VI ). In addition to these were the original 32 bonbers which were later converted to transport standard, and 10-12 Albemarle transports aircraft which were delivered to the Soviet Air Force from RAF stocks. All Albemarles utilised the same Bristol Hercules XI engine, with the exception of the sole Albemarle Mk IV prototype which was tried with a pair of Wright Double Cyclone radial engines. Albemarle marks mainly differed only in their equipment.

Whilst not a particularly significant type, the Albemarle did perform a useful role and therefore released other types for more vital tasks. In addition, because of Its method of construction and the materials used, production did not unduly disrupt the flow of more important aircraft at a time when these were vital to Britain's survival.

Bibliography

Aircraft of World War II by Chris Chant (Dempsey-Parr, 1999)
World Aircraft Information Files (Aerospace Publishing Periodical).

Hobilar · 11-09-2007, 06:00 AM

pbfoot · 11-09-2007, 06:44 PM

would it be possible for you to put all these posts together rather then several

Soundbreaker Welch? · 11-09-2007, 08:17 PM

Thanks the article. It's news to me.

Hobilar · 11-10-2007, 04:38 AM

Quote:

Originally Posted by pbfoot

would it be possible for you to put all these posts together rather then several

I could, but like many others I suspect, I find excessively long posts tiring to read on a bright screen. This is why I have elected to split longer posts into more manageable bites.

Airborne · 11-10-2007, 04:48 AM

Footy quote: would it be possible for you to put all these posts together rather then several

Hobilar is the post count king. You havn't changed Hobilar...LOL

Graeme · 11-10-2007, 04:00 PM

Flight testing at Boscombe Down was very critical of the Albemarle.

Performance was mediocre. (Speed and ceiling)
The twin rudders lacked sufficient travel, were too heavy to maintain straight flight on one engine and the aileron and rudder trimmers were poor.
The nose wheel brake was ineffective.
Trials of the upper turret revealed its draughtiness, and lowering the ventral turret at speeds up to 273mph caused snaking. Even when the turret was retracted flight characteristics were judged as unpleasant and distinctly uncomfortable at aft CG.
Poor crew heating-non existent aft of the spar, was expected to cause extreme discomfort for operational crews, especially in the cold upper turret.

Extremely poor performance at high weights.
Take-off distance was longer on concrete compared to grass.
Most damming of the comments following intensive flying was that the wooden structure of the wings warped in the rain when parked outside in spite of the use of a cover and liberal floor polish; the Albemarle was considered unsuitable for operational use.
Extremely difficult to load bombs. The hoisting winch was located outside the fuselage and the cable threaded tortuously down through the bay for each bomb, and it was found nearly impossible to reach around the bombs to make the necessary connections.
As a glider tug persistent overheating of the engines was the norm. Various shrouds, baffles, extra cooling holes in the nacelles and semi-flared propellers were all tried but the cylinders remained prone to overheating.
The Mk IV ceiling was even lower with Wright Cyclone engines and the mountings were too rigid, leading to structural breakages.

“The Secret Years” by Tim Mason.

pbfoot · 11-10-2007, 05:40 PM

Quote:

Originally Posted by Hobilar

I could, but like many others I suspect, I find excessively long posts tiring to read on a bright screen. This is why I have elected to split longer posts into more manageable bites.

Wildcat · 11-10-2007, 06:34 PM

Excellent info there Graeme!

11-09-2007, 05:52 AM	#1
Hobilar Senior Member Join Date: Nov 2007 Location: Lincoln Posts: 111	Armstrong Whitworth A.W.41 Albemarle The Albemarle originated as the Bristol type 155 design to meet an Air Ministry requirement of 1938 for a twin engined bomber. Production was transferred to Armstrong Whitworth when it became clear that the latter had spare design and production capacity. A design team under the supervision of John Lloyd was set the difficult task of taking over another company's creation and adapting it to meet a revised Ministry requirement for a reconnaissance bomber. The revised Armstrong Whitworth design was very different from the original Bristol concept in detail and construction. The airframe was of mixed composite steel and wood (thereby reducing demand for strategic light alloys). Most of the components were produced by subcontractors (one source mentions almost 1,000 sub contractors even to small companies outside the aircraft industry), with final assembly being made by A.W. Hawksley Ltd. The Albemarle was the first operational aircraft in RAF service to have a tricycle undercarriage. This was of Lockheed design.

11-09-2007, 08:17 PM	#6
Soundbreaker Welch? Senior Member Join Date: Feb 2006 Location: Colorado, USA Posts: 1,893	Thanks the article. It's news to me. __________________ "His motor's conked out!" "What's the differance, they're all Nazis!" "Luke, shut up!" "Fear the hook!" "Oh.....I wanna fly." "You mean the kind that go under water and fly up the stairs?" "What you doing? Oh Nooooo!"

11-10-2007, 06:34 PM	#11
Wildcat Senior Member Join Date: Apr 2005 Location: Queensland Posts: 4,543	Excellent info there Graeme! __________________

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11-09-2007, 05:54 AM	#2
Hobilar Senior Member Join Date: Nov 2007 Location: Lincoln Posts: 111	The first of two prototypes flew on 20 March 1940 but proved to be a poor performer as a result of its great structural weight. This machine was destroyed in a crash before the flight of the second prototype in January 1941. The first three aircraft (after considerable delay in establishing production lines) emerged from the factory in December 1941. The first 32 production aircraft were built as bombers, although they were not used as such. These aircraft were installed with a four-gun Boulton Paul dorsal turret, but weight considerations dictated the removal of this in later aircraft, being replaced by a pair of Vickers 'K' hand operated machine guns. Deliveries to the Royal Air Force began in January 1943 when No.295 Squadron received its first aircraft. By this time the decision had been made to adapt the type as a glider tug and airborne forces transport. The Albemarle was blooded by No.296 and 297 Squadrons RAF (part of No.38 Wing) operating from North Africa, in the invasion of Sicily in July 1943. On D-Day (6 June 1944) six of No.295 Squadron's Albemarle aircraft. Operating from Harwell, served as pathfinders for the 6th Airborne Division's paratrooper drop over Normandy. In addition four squadrons of the type acted as glider tugs. In September 1944 two Squadrons of Albemarles towed gliders carrying troops of the 1st Airborne Division as a part of the Arnhem operation.

11-09-2007, 05:57 AM	#3
Hobilar Senior Member Join Date: Nov 2007 Location: Lincoln Posts: 111	Production ceased in December 1944 after the completion of 602 aircraft. An order for a second batch of 478 machines was cancelled. Albemarle deliveries to the RAF consisted of 310 transport aircraft (78 Albemarle ST Mk.I, 99 Albemarle ST Mk.II and 133 Albemarle ST Mk.VI) and 246 glider tugs (80 Albemarle GT MkI, one Albemarle GT MkII, 49 Albemarle GT Mk V, and 117 Albemarle Mk VI ). In addition to these were the original 32 bonbers which were later converted to transport standard, and 10-12 Albemarle transports aircraft which were delivered to the Soviet Air Force from RAF stocks. All Albemarles utilised the same Bristol Hercules XI engine, with the exception of the sole Albemarle Mk IV prototype which was tried with a pair of Wright Double Cyclone radial engines. Albemarle marks mainly differed only in their equipment. Whilst not a particularly significant type, the Albemarle did perform a useful role and therefore released other types for more vital tasks. In addition, because of Its method of construction and the materials used, production did not unduly disrupt the flow of more important aircraft at a time when these were vital to Britain's survival. Bibliography Aircraft of World War II by Chris Chant (Dempsey-Parr, 1999) World Aircraft Information Files (Aerospace Publishing Periodical).

11-09-2007, 06:00 AM	#4
Hobilar Senior Member Join Date: Nov 2007 Location: Lincoln Posts: 111

11-09-2007, 06:44 PM	#5
pbfoot Senior Member Join Date: Apr 2005 Location: niagara falls Posts: 5,586	would it be possible for you to put all these posts together rather then several

11-10-2007, 04:48 AM	#8
Airborne Banned Join Date: Nov 2007 Location: Perth Australia Posts: 82	Footy quote: would it be possible for you to put all these posts together rather then several Hobilar is the post count king. You havn't changed Hobilar...LOL

11-10-2007, 04:00 PM	#9
Graeme Senior Member Join Date: May 2007 Posts: 2,081	Flight testing at Boscombe Down was very critical of the Albemarle. Performance was mediocre. (Speed and ceiling) The twin rudders lacked sufficient travel, were too heavy to maintain straight flight on one engine and the aileron and rudder trimmers were poor. The nose wheel brake was ineffective. Trials of the upper turret revealed its draughtiness, and lowering the ventral turret at speeds up to 273mph caused snaking. Even when the turret was retracted flight characteristics were judged as unpleasant and distinctly uncomfortable at aft CG. Poor crew heating-non existent aft of the spar, was expected to cause extreme discomfort for operational crews, especially in the cold upper turret. Extremely poor performance at high weights. Take-off distance was longer on concrete compared to grass. Most damming of the comments following intensive flying was that the wooden structure of the wings warped in the rain when parked outside in spite of the use of a cover and liberal floor polish; the Albemarle was considered unsuitable for operational use. Extremely difficult to load bombs. The hoisting winch was located outside the fuselage and the cable threaded tortuously down through the bay for each bomb, and it was found nearly impossible to reach around the bombs to make the necessary connections. As a glider tug persistent overheating of the engines was the norm. Various shrouds, baffles, extra cooling holes in the nacelles and semi-flared propellers were all tried but the cylinders remained prone to overheating. The Mk IV ceiling was even lower with Wright Cyclone engines and the mountings were too rigid, leading to structural breakages. “The Secret Years” by Tim Mason.