General Aircraft Hotspur
GAL.48 Hotspur | |
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Two Hotspur Mark IIs in free flight over the Oxfordshire countryside. | |
Role | Training glider |
Manufacturer | General Aircraft Ltd |
First flight | 5 November, 1940[1] |
Primary users | British Army Royal Air Force |
Produced | 1940–1943 |
Number built | 1,015[1] |
The General Aircraft GAL.48 Hotspur was a military glider designed and built by the British company General Aircraft Ltd during the Second World War. When the British airborne establishment was formed in 1940 by the order of the Prime Minister, Winston Churchill, it was decided that gliders would be used to transport airborne troops into battle. General Aircraft Ltd were given a contract by the Ministry of Aircraft Production in June 1940 to design and produce an initial glider for use by the airborne establishment which resulted in the Hotspur.
Although originally conceived as an "assault" glider which necessitated a compact design, a change in tactical philosophy predicated against the use of small numbers of troops being sent into battle aboard gliders. Due to limitations in its design, the Hotspur was mainly relegated to training where it excelled and became the basic trainer for the glider schools that were formed. [2]
Development
Operational requirements
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/80/Hotspur_training.jpg/220px-Hotspur_training.jpg)
The German military was one of the pioneers of the use of airborne formations, conducting several successful airborne operations during the Battle of France in 1940, including the Battle of Fort Eben-Emael.[3] Impressed by the success of German airborne operations, the Allied governments decided to form their own airborne formations.[4] This decision would eventually lead to the creation of two British airborne divisions, as well as a number of smaller units.[5] The British airborne establishment began development on 22 June 1940, when the Prime Minister, Winston Churchill, directed the War Office in a memorandum to investigate the possibility of creating a corps of 5,000 parachute troops.[6] When the equipment to be used by the airborne forces was under development, it was decided by War Office officials that gliders would be an integral component of such a force; these would be used to transport troops and heavy equipment.[7]
On 21 June, 1940, the Central Landing Establishment was formed at Ringway airfield near Manchester; although tasked primarily with training parachute troops, it was also directed to investigate the possibilities of using gliders to transport troops into battle.[8][9] It had been decided that the Royal Air Force and the Army would cooperate in forming the airborne establishment, and as such Squadron Leader L.A. Strange and Major J.F. Rock were tasked with gathering together potential glider pilots and forming a glider unit; this was achieved by searching for members of the armed forces who had pre-war experience of flying gliders, or were interested in learning to do so.[9] The two officers and their newly-formed unit were provided with four obsolecent Armstrong Whitworth Whitley bombers and a small number of Tiger Moth and Avro 504 biplanes for towing purposes.[10]
As this new unit was in the process of being formed, in June the Ministry of Aircraft Production contracted General Aircraft Ltd to design and produce an initial glider type for use by the airborne establishment.[11] It would be used for both assault and training purposes, and would be capable of transporting eight airborne troops.[10] The glider had to be capable of a long approach during landing, due to the prevailing belief at the time that gliders would have to be cast off from a considerable distance from the target and glide in to ensure the sound of the towing aircraft did not alert the enemy. It therefore had to be aerodynamically stable, but also cheap and easy to construct as it would only be used once.[1] The Hotspur was intended to have an operational range of 100 miles (160 km) when released at high altitude, although in practice this was reduced to 80 miles (130 km) when released from a height of 20,000 feet (6,100 m). [12]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/75/Hotspur_IWM.jpg/220px-Hotspur_IWM.jpg)
Design
The GAL.48 was primarily designed by F.F. Crocombe (team leader)[13] to the Air Ministry specification X.10/40, and was to be similar in design to the German DFS 230 assault glider which had been used during the Battle of the Netherlands.[14][15] The first prototype of the glider, built under the company designation GAL.48 and which would receive the service name Hotspur Mk I, flew in November, only four months after General Aircraft Ltd had been given the requirement for the glider.[10] An initial order of 400 Hotspurs was placed with General Aircraft Ltd in September by the Ministry of Aircraft Production, a month before the prototype first flew.[11]
The Hotspur Mark I was constructed from wood and was designed to accommodate eight fully-armed airborne troops. It possessed a wingspan of 62 feet (19 m) and was 39 feet 3.5 inches (11.976 m) in length.[16] With a full load, which was approximately 1,880 pounds (850 kg),[17] it weighed approximately 3,600 pounds (1,600 kg).[18] The Mk I was distinguished from its other variants by the addition of cabin portholes along its fuselage,[16] as well as the addition of hooks on the nose and tail to allow multiple Hotspurs to be towed together.[19] The two pilots, and later the pilot and instructor when the Hotspurs were used as training gliders, sat in tandem next to each other in the cockpit.[20] It also possessed a jettisonable undercarriage, as well as an unusual fuselage that functioned like a lid; once the Hotspur had landed, the troops inside would throw off the top half of the fuselage and then climb out of the lower half, much like leaving a small boat.[1] A total of 18 Hotspur Mk Is were produced, 10 by GAl and eight by Slingsby Aircraft. [13]
The first operational Hotspur arrived at the Central Landing Establishment between February and April of 1941,[Note 1] with 15 being delivered by 22 August.[21] Towing trials began in February 1941 with a Boulton & Paul Overstrand bomber. [22]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Hotspur_on_ground.jpg/220px-Hotspur_on_ground.jpg)
Further development
Even as the initial 400 gliders were being produced, several problems with the Hotspur's design were rapidly discovered, the primary one being that the glider did not carry sufficient troops. Although it had been designed to transport eight airborne troops and a cargo of 1,880 pounds (850 kg), this was found to be inadequate. Tactically it was believed that airborne troops should be landed in groups far larger than eight, and the number of aircraft therefore required to tow the gliders needed to land larger groups would be unfeasible; there were also concerns that the gliders would have to be towed in tandem if used operationally, which would be extremely difficult during nighttime and through cloud formations.[17] The inability to meet operational requirements for range was also a contributing factor to reevaluate the assault glider concept. [23]
Due to the limitations inherent in the Hotspur design, the decision was made to continue with the development of several other types of gliders, including a 15-seater which would become the Airspeed Horsa and a tank-carrying glider, which would eventually come in the form of the General Aircraft Hamilcar.[17] The Hotspur remained in production primarily as a training aircraft and as a "stop-gap" in case the other programmes failed.[13]
Three variants on the original Hotspur Mk I were created. The first was the heavily-modified Mk II (Specification X.22/40 and X.23/40), which was redesigned partially to address changes in operational requirements and also to bolster the ground handling of the initial series of aircraft. In operations, rather than casting the glider off from a long distance away and allowing it to glide gently to the ground, it was decided that the towing aircraft would approach the landing zone and only then release the glider, requiring a more robust glider.[1] The Hotspur Mk I wings had also shown considerable flex and the type had proved difficult to handle on the ground. In order to reduce stresses on the airframe, the fuselage was strengthened and wings were "shortened" by eight ft to a length of 45 feet 10.75 inches (13.9891 m) with the tips made square-cut and ailerons moved from the end of the wings to an inset position. [23]
While maintaining its original all-wood construction and overall dimensions, the Mk II incorporated a modified fuselage which included altering the cockpit enclosure and a "deeper" canopy. Instead of using the "lid" (where the two pilots still boarded via the hinged Plexiglass canopy),[24] two side doors were added from which troops would enter and depart.[1] Further alterations included a new seating arrangement and a braking parachute added to the rear.[16] Its other dimensions remained the same, however, with a length of 39 feet 3.5 inches (11.976 m) and a weight of approximately 3,600 pounds (1,600 kg) when it was fully loaded with eight airborne troops and a cargo weighing approximately 1,880 pounds (850 kg).[25]
A total of 50 early production Mk IIs were modified into trainers as the Mark III.[13] This variant added completely duplicated dual controls and instruments for the student pilot, and an externally braced tailplane.[26]
The third variant of the Hotspur was known as the GAL.48B "Twin Hotspur", although it did not progress past the prototype phase.[16] The Twin Hotspur was an attempt in 1942 to create a glider capable of carrying 15 airborne troops as an interim glider until production of the Horsa reached sufficient levels. It was created by taking two Hotspurs, removing their inner wings and then attaching them to each other with a centre section 12 feet (3.66 m) long, as well as a new tail centre section spanning the distance between the two fuselages. Two pilots sat tandem-style in the port fuselage.[27] In August 1942, the sole "Twin Hotspur" prototype (MP486) underwent testing, towed behind an Armstrong Whitworth Whitley tug. [13] The project was abandoned before production could begin, primarily due to the fact that the glider was unpopular with those chosen to pilot it.[19]
Production
When production of the Hotspur came to an end in early 1943, a total of 1,015 gliders had been produced. The primary sub-contractor, Harris Lebus was responsible for 996 Mk IIs and Mk IIIs while the parent company produced only 10 Mk Is and a single Mk II prototype. Slingsby was the only other sub-contractor involved in production with eight Mk Is completed.[13]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/bc/Hotspur_in_air.jpg/220px-Hotspur_in_air.jpg)
Operational history
Due to the problems perceived with its design, no Hotspurs were eventually used in combat operations, and were instead exclusively used for training purposes; it was the glider in which all pilots belonging to the Glider Pilot Regiment received their initial instruction.[17] Although relatively heavy with a high sink rate, the Hotspur exhibited good flying characteristics and could even be flown aerobatically, allowing novice pilots to quickly gain proficiency. [12]
Glider pilots first trained at an Elementary Flying Training School on de Havilland Tiger Moths or Miles Magisters before converting to glider training. At the Glider Schools, a Hotspur MK III was first employed for dual instruction with the rear seats weighted for ballast and only the instructor and student aboard. The gliders were usually towed by Hawker Hector or Hawker Audax biplanes (later Miles Master and Westland Lysander "tugs")[13] during training.[28] An average of 8 to 11 flights were required before the pupil was allowed to solo. At Operational Training Glider Schools, the flights were made with troops instead of ballast in Hotspur MK IIs. Release at high altitudes and night-flying was also part of the training. [29]
A total of 250 Hotspurs were retained for operational use if they were required, but the remainder of the production series were issued for use as a training glider.[15] In 1942, a total of 22 Hotspur Mk IIs were sent to Canada, eventually six were redeployed to the United States Navy and one to the United States Army Air Forces. [13] In the build-up to Operation Overlord in 1944, a scheme was considered in which Hotspurs would have been used as freighters to transport cargo and equipment, but this did not get past the planning stage.[1] At war's end, the type was retired and relatively few Hotspurs were preserved for display.
Variants
- Hotspur Mk I
- Single prototype, production run of 18 aircraft.
- Hotspur Mk II
- Production series, modified with reduced wingspan, inset ailerons, new seating arrangement, deeper cockpit canopy, side doors, braking parachute; fuselage strengthened.
- Hotspur Mk III
- Production series, duplicated dual controls and instruments for the student pilot, external bracing for tailplane.
- Twin Hotspur
- Two standard Hotspur fuselages and outer wing panels joined together with common centre section and tailplane; single prototype made. This variant did not enter series production.[27]
Operators
![](http://upload.wikimedia.org/wikipedia/en/thumb/9/9f/Hotspur_RCAF.jpg/220px-Hotspur_RCAF.jpg)
Survivors
A Hotspur Mark II (HH268) replica is on display at the Museum of Army Flying in Hampshire, England.[30] The front fuselage of a Hotspur was preserved at the Parachute Regiment And Airborne Forces Museum in Aldershot prior to the museum closing in 2007, in anticipation of a move to the Imperial War Museum Duxford.[31]
Specifications (Hotspur Mk II)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/TWIN_HOTSPUR.jpg/200px-TWIN_HOTSPUR.jpg)
Data from The Encyclopedia of Weapons of World War II[16][18]
General characteristics
- Crew: 2
- Capacity: 8 troops
Performance
See also
Aircraft of comparable role, configuration, and era
Related lists
- List of aircraft of the RAF
- List of aircraft of the Army Air Corps
- List of World War II military gliders
Notes
- ^ Smith (p. 13) and other sources, e.g. Ringway state that the first Hotspur arrived at the CLE on 6 February 1941 while Otway (p. 30) states that it arrived in April 1941.
References
- Notes
- ^ a b c d e f g Otway 1990, p. 390.
- ^ Munson 1972, p. 199.
- ^ Flanagan 2002, p. 6.
- ^ Harclerode 2005, p. 197.
- ^ Harclerode 2005, p. 107.
- ^ Otway 1990, p. 21.
- ^ Flint 2006, p. 15.
- ^ Otway 1990, pp. 28–29.
- ^ a b Smith 1992, p. 7.
- ^ a b c Lynch 2008, p. 31.
- ^ a b Flint 2006, p. 73.
- ^ a b Brown 1999, p. 18.
- ^ a b c d e f g h Swanborough 1997, p. 50.
- ^ Flint 2006, p. 35.
- ^ a b Otway 1990, p. 23.
- ^ a b c d e Bishop 2002, p. 412.
- ^ a b c d Smith 1992, p. 13.
- ^ a b Otway 1990, p. 397.
- ^ a b Otway 1990, p. 391.
- ^ Smith 1992, pp. 12–13.
- ^ Otway 1990, p. 30.
- ^ "Gliders." Ringway. Retrieved: 7 June 2009.
- ^ a b Mondey 2002, p. 108.
- ^ Morrison 1999, p. 64 (illustration caption)
- ^ Smith 1992, pp. 13–14.
- ^ March 1998, p. 122.
- ^ a b Bridgman 1989, p. 122.
- ^ Brown 1999, p. 24.
- ^ Morrison 1999, pp. 19–22.
- ^ "Collection - The Glider Pilot Regiment." Museum of Army Flying. Retrieved: 20 May 2009.
- ^ Vituci, Vince. "Museums Etc.: Hampshire & Dorset." daveg4otu.tripod.com, Hampshire Aviation Museums. Retrieved: 7 June 2009.
- Bibliography
- Bishop, Chris. The Encyclopedia of Weapons of World War II: The Comprehensive Guide to Over 1,500 Weapons Systems, Including Tanks, Small Arms, Warplanes, Artillery, Ships and Submarines. New York: Sterling Publishing Company, Inc., 2002. ISBN 1-58663-762-2.
- Brown, Robert G. On the Edge: Personal Flying Experiences During the Second World War. Renfrew, Ontario, Canada: General Store Publishing House, 1999. ISBN 978-1896182872.
- Bridgman, Leonard, ed. Jane's Fighting Aircraft of World War II. London: Bracken Books, 1989. ISBN 1-85170-199-0.
- Flanagan, E. M. Jr. Airborne: A Combat History Of American Airborne Forces. New York: The Random House Publishing Group, 2002. ISBN 0-89141-688-9.
- Flint, Keith. Airborne Armour: Tetrarch, Locust, Hamilcar and the 6th Airborne Armoured Reconnaissance Regiment 1938-1950. Solihull, W. Midlands, UK: Helion & Company Ltd, 2006. ISBN 1-874622-37-X.
- Harclerode, Peter. Wings Of War: Airborne Warfare 1918-1945. London: Weidenfeld & Nicolson, 2005. ISBN 0-30436-730-3.
- Lynch, Tim. Silent Skies: Gliders At War 1939-1945. Barnsley, UK: Pen & Sword Military, 2008. ISBN 0-75030-633-5.
- March, Daniel J. British Warplanes of World War II. London: Aerospace Publishing, 1998. ISBN 1-874023-92-1.
- Mondey, David. The Hamlyn Concise Guide to British Aircraft of World War II. London: Chancellor Press, 2002. ISBN 1-85152-668-4.
- Morrison, Alexander. Silent Invader: A Glider Pilot's Story of the Invasion of Europe in World War II (Airlife Classics). Shrewsbury, UK: Airlife, 1999. ISBN 978-1840373684 .
- Munson, Kenneth. Aircraft of World War II. New York: Doubleday and Company, 1972. ISBN 0-385-07122-1.
- Otway, Lieutenant-Colonel T.B.H. The Second World War 1939-1945 Army: Airborne Forces. London: Imperial War Museum, 1990. ISBN 0-90162-75-77.
- Smith, Claude. History of the Glider Pilot Regiment. London: Pen & Sword Aviation, 1992. ISBN 1-84415-626-5.
- Swanborough, Gordon. British Aircraft at War, 1939-1945. East Sussex, UK: HPC Publishing, 1997. ISBN 0-9531421-0-8.
- Thetford, Owen. Aircraft of the Royal Air Force 1918-57. London: Putnam, 1968. ISBN 0-370-00101-X.