The mechanical structure of an aircraft is known as the airframe . This structure is typically considered to include the fuselage , undercarriage , empennage and wings , and excludes the propulsion system .
116-612: The Aircraft Restoration Company (formally Historic Flying Limited ) is a British company that specialises in the restoration and new-build of Supermarine Spitfires and other historic aircraft. It is based at the former RAF Duxford in Cambridgeshire, UK. The company was founded in the late 1980s to restore five Spitfires to flying condition; these had been " gate guardians " at Royal Air Force stations. Since then, over 30 Spitfires have been restored or built from scratch - using salvaged parts where available - or restored. This
232-577: A commercial aircraft ; composites are increasingly used since in Airbus airliners: the horizontal stabilizer of the A320 in 1987 and A330 / A340 in 1994, and the center wing-box and aft fuselage of the A380 in 2005. The Cirrus SR20 , type certificated in 1998, was the first widely produced general aviation aircraft manufactured with all-composite construction, followed by several other light aircraft in
348-799: A dry-fiber resin transfer infusion wing with a lightweight aluminium-lithium alloy fuselage for damage resistance and repairability, a combination which could be used for future narrow-body aircraft . In 2016, the Cirrus Vision SF50 became the first certified light jet made entirely from carbon-fiber composites. In February 2017, Airbus installed a 3D printing machine for titanium aircraft structural parts using electron beam additive manufacturing from Sciaky, Inc. Airframe production has become an exacting process. Manufacturers operate under strict quality control and government regulations. Departures from established standards become objects of major concern. A landmark in aeronautical design,
464-490: A few aerobatic tests to determine how good or bad she was. The production test was usually quite a brisk affair; the initial circuit lasted less than 10 minutes and the main flight took between 20 and 30 minutes. Then, the aircraft received a final once-over by our ground mechanics, any faults were rectified, and the Spitfire was ready for collection. I loved the Spitfire in all of her many versions, but I have to admit that
580-606: A field of aerospace engineering that combines aerodynamics , materials technology and manufacturing methods with a focus on weight, strength and aerodynamic drag , as well as reliability and cost. Modern airframe history began in the United States during the Wright Flyer's maiden flight, showing the potential of fixed-wing designs in aircraft. In 1912 the Deperdussin Monocoque pioneered
696-498: A jig and the eight horizontal tail formers were riveted to them. A combination of 14 longitudinal stringers and four main longerons attached to the frames helped form a light but rigid structure to which sheets of alclad stressed skinning were attached. The fuselage plating was 24, 20, and 18 gauge , decreasing in order of thickness towards the tail, while the fin structure was completed using short longerons from frames 20 to 23, before being covered in 22 gauge plating. The skin of
812-483: A large penalty for their fuel injection. When the fuel is fed before the supercharger, as on the Merlin, it evaporates and cools the air by 25°C. This cooling enhances the performance of the supercharger, and increases the power of the engine, with a corresponding increase in aircraft speed, particularly at high altitude." However, the early Merlin engine's lack of fuel injection meant that Spitfires and Hurricanes, unlike
928-567: A large, fixed, spatted undercarriage powered by the 600-horsepower (450 kW), evaporatively cooled Rolls-Royce Goshawk engine. It made its first flight in February 1934. Of the seven designs tendered to F7/30, the Gloster Gladiator biplane was accepted for service. The Type 224 was a big disappointment to Mitchell and his design team, who immediately embarked on a series of "cleaned-up" designs, using their experience with
1044-515: A lower attrition rate and a higher victory-to-loss ratio than Hurricanes, most likely due to the Spitfire's higher performance. During the battle, Spitfires generally engaged Luftwaffe fighters—mainly Messerschmitt Bf 109E –series aircraft, which were a close match for them. After the Battle of Britain, the Spitfire superseded the Hurricane as the principal aircraft of RAF Fighter Command , and it
1160-507: A maximum rate of 320 per month, making CBAF the largest Spitfire factory in the UK and the largest and most successful plant of its type during the 1939–45 conflict. During the Battle of Britain, the Luftwaffe made concerted efforts to destroy the main manufacturing plants at Woolston and Itchen , near Southampton. The first bombing raid, which missed the factories, came on 23 August 1940. Over
1276-589: A piecemeal basis. The British public first saw the Spitfire at the RAF Hendon air display on Saturday 27 June 1936. Although full-scale production was supposed to begin immediately, numerous problems could not be overcome for some time, and the first production Spitfire, K9787 , did not roll off the Woolston , Southampton assembly line until mid-1938. In February 1936, the director of Vickers-Armstrongs, Sir Robert MacLean guaranteed production of five aircraft
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#17327978527821392-567: A result, the Spitfire's performance and capabilities improved over the course of its service life. During the Battle of Britain (July–October 1940), the more numerous Hurricane flew more sorties resisting the Luftwaffe , but the Spitfire captured the public's imagination as the main RAF fighter, in part because the Spitfire was generally a better fighter aircraft than the Hurricane. Spitfire units had
1508-446: A similar fashion to a leaf spring ; two of these booms were linked together by an alloy web, creating a lightweight and very strong main spar. The undercarriage legs were attached to pivot points built into the inner, rear section of the main spar, and retracted outwards and slightly backwards into wells in the non-load-carrying wing structure. The resultant narrow undercarriage track was considered an acceptable compromise as this reduced
1624-419: A total of 2,360 Spitfires and Seafires, more than 10% of total production. Henshaw wrote about flight testing Spitfires: After a thorough preflight check, I would take off, and once at circuit height, I would trim the aircraft and try to get her to fly straight and level with hands off the stick ... Once the trim was satisfactory, I would take the Spitfire up in a full-throttle climb at 2,850 rpm to
1740-563: A week, beginning 15 months after an order was placed. On 3 June 1936, the Air Ministry placed an order for 310 aircraft. Full-scale production of the Spitfire began at Supermarine's facility in Woolston, but the order clearly could not be completed in the 15 months promised. Supermarine was a small company, already busy building Walrus and Stranraer flying boats, and Vickers was busy building Wellington bombers. The initial solution
1856-409: A wing shape from an aircraft designed for an entirely different purpose." The elliptical wing was decided upon quite early on. Aerodynamically it was the best for our purpose because the induced drag caused in producing lift, was lowest when this shape was used: the ellipse was ... theoretically a perfection ... To reduce drag we wanted the lowest possible thickness-to-chord, consistent with
1972-489: Is accompanied by enhanced structural integrity and performance reliability. Electric resistance spot and seam welding are used to join secondary structures, such as fairings, engine cowls, and doublers, to bulkheads and skins. Difficulties in quality control have resulted in low utilization of electric resistance welding for primary structure. Ultrasonic welding offers some economic and quality-control advantages for production joining, particularly for thin sheet. However,
2088-505: Is alclad 2024-T3. The internal structure comprises stringers, spars, bulkheads, chord members, and various attaching fittings made of aluminum extrusions, formed sheet, forgings, and castings. The alloys most used for extruded members are 2024-T4 for sections less than 0.125 in. thick and for general application, and 2014-T6 for thicker, more highly stressed sections. Alloy 6061-T6 has considerable application for extrusions requiring thin sections and excellent corrosion resistance. Alloy 2014-T6
2204-448: Is compromise, and an improvement at one end of the performance envelope is rarely achieved without a deterioration somewhere else. When the last Spitfire rolled out in February 1948, a total of 20,351 examples of all variants had been built, including two-seat trainers , with some Spitfires remaining in service well into the 1950s. The Spitfire was the only British fighter aircraft to be in continuous production before, during, and after
2320-465: Is critical under compressive loading . Alloy 7079-T6 was introduced in the United States in 1954. In forged sections over 3 in. thick, it provides higher strength and greater transverse ductility than 7075-T6. It now is available in sheet, plate, extrusions, and forgings. Alloy X7080-T7, with higher resistance to stress corrosion than 7079-T6, is being developed for thick parts. Because it
2436-438: Is relatively insensitive to quenching rate, good strengths with low quenching stresses can be produced in thick sections. Cladding of aluminum alloys was developed initially to increase the corrosion resistance of 2017-T4 sheet and thus to reduce aluminum aircraft maintenance requirements. The coating on 2017 sheet - and later on 2024-T3 - consisted of commercial-purity aluminum metallurgically bonded to one or both surfaces of
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#17327978527822552-618: Is required. Alloys 3003, 6061, and 6951 are utilized extensively in brazed heat exchangers and hydraulic accessories. Recently developed alloys, such as 5086, 5454, 5456, 6070, and the new weldable aluminum-magnesium-zinc alloys, offer strength advantages over those previously mentioned. Sheet assembly of light aircraft is accomplished predominantly with rivets of alloys 2017-T4, 2117-T4, or 2024-T4. Self-tapping sheet metal screws are available in aluminum alloys, but cadmium-plated steel screws are employed more commonly to obtain higher shear strength and driveability. Alloy 2024-T4 with an anodic coating
2668-665: Is said to be a third of the Spitfires that are now airworthy . The organisation has also completed major maintenance work on the RAF's Battle of Britain Memorial Flight aircraft, for which the Stephenson Hangar was purpose-built. The latest of this work included the minor maintenance of the BBMF's Avro Lancaster which was completed at the end of summer 2021. The Aircraft Restoration Company operates and maintains
2784-865: Is the primary forging alloy, especially for landing gear and hydraulic cylinders. Alloy 6061-T6 and its forging counterpart 6151-T6 often are utilized in miscellaneous fittings for reasons of economy and increased corrosion performance, when the parts are not highly stressed. Alloys 356-T6 and A356-T6 are the primary casting alloys employed for brackets, bellcranks, pulleys, and various fittings. Wheels are produced in these alloys as permanent mold or sand castings. Die castings in alloy A380 also are satisfactory for wheels for light aircraft. For low-stressed structure in light aircraft, alloys 3003-H12, H14, and H16; 5052-O, H32, H34, and H36; and 6061-T4 and T6 are sometimes employed. These alloys are also primary selections for fuel, lubricating oil, and hydraulic oil tanks, piping, and instrument tubing and brackets, especially where welding
2900-471: Is to specify castings only in places where failure of the part cannot cause loss of the airplane. Redundancy in cable and hydraulic control systems permits the use of castings. Casting technology has made great advances in the last decade. Time-honored alloys such as 355 and 356 have been modified to produce higher levels of strength and ductility. New alloys such as 354, A356, A357, 359 and Tens 50 were developed for premium-strength castings. The high strength
3016-554: The Douglas X-3 Stiletto was the first titanium aircraft but it was underpowered and barely supersonic ; the Mach 3.2 Lockheed A-12 and SR-71 were also mainly titanium, as was the cancelled Boeing 2707 Mach 2.7 supersonic transport . Because heat-resistant titanium is hard to weld and difficult to work with, welded nickel steel was used for the Mach 2.8 Mikoyan-Gurevich MiG-25 fighter, first flown in 1964; and
3132-571: The McDonnell Douglas AV-8B Harrier II , F/A-18 Hornet and Northrop Grumman B-2 Spirit . Airbus and Boeing are the dominant assemblers of large jet airliners while ATR , Bombardier and Embraer lead the regional airliner market; many manufacturers produce airframe components. The vertical stabilizer of the Airbus A310 -300, first flown in 1985, was the first carbon-fiber primary structure used in
3248-486: The NACA 2200 series , which had been adapted to create a thickness-to-chord ratio of 13% at the root, reducing to 9.4% at the tip. A dihedral of 6° was adopted to give increased lateral stability. A wing feature that contributed greatly to its success was an innovative spar boom design, made up of five square tubes that fitted into each other. As the wing thinned out along its span, the tubes were progressively cut away in
3364-641: The Schneider Trophy seaplanes as a starting point. This led to the Type 300, with retractable undercarriage and a wingspan reduced by 6 ft (1.8 m). This design was submitted to the Air Ministry in July 1934, but was not accepted. It then went through a series of changes, including the incorporation of an enclosed cockpit, oxygen-breathing apparatus, smaller and thinner wings, and the newly developed, more powerful Rolls-Royce PV XII V-12 engine , which
3480-601: The Spirit of St. Louis flown across the Atlantic by Charles Lindbergh in 1927. William Stout designed the all-metal Ford Trimotors in 1926. The Hall XFH naval fighter prototype flown in 1929 was the first aircraft with a riveted metal fuselage : an aluminium skin over steel tubing, Hall also pioneered flush rivets and butt joints between skin panels in the Hall PH flying boat also flying in 1929. Based on
3596-412: The aerodrome , and the installation of the most modern machine tools then available began two months after work started on the site. Although Morris Motors, under Lord Nuffield (an expert in mass motor-vehicle construction), managed and equipped the factory, it was funded by the government. By the beginning of 1939, the factory's original estimated cost of £2,000,000 had more than doubled, and even as
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3712-408: The angle of incidence decreasing from +2° at its root to -½° at its tip. This caused the wing roots to stall before the tips, reducing tip-stall that could otherwise have resulted in a wing drop, often leading to a spin. As the wing roots started to stall, the separating air stream started to buffet (vibrate) the aircraft, warning the pilot, allowing even relatively inexperienced pilots to fly it to
3828-579: The shadow factory plan , to boost British aircraft production capacity under the leadership of Herbert Austin . He was given the task of building nine new factories, and to supplement the British car-manufacturing industry by either adding to overall capacity or increasing the potential for reorganisation to produce aircraft and their engines. In 1938, construction began on the Castle Bromwich Aircraft Factory (CBAF), next to
3944-480: The 1916 LFG Roland C.II , and would later be licensed to Pfalz Flugzeugwerke for its D-series biplane fighters. In 1916 the German Albatros D.III biplane fighters featured semi-monocoque fuselages with load-bearing plywood skin panels glued to longitudinal longerons and bulkheads ; it was replaced by the prevalent stressed skin structural configuration as metal replaced wood. Similar methods to
4060-538: The 1930s. The J 1 of 1915, and the D.I fighter of 1918, were followed in 1919 by the first all-metal transport aircraft, the Junkers F.13 made of Duralumin as the D.I had been; 300 were built, along with the first four- engine , all-metal passenger aircraft , the sole Zeppelin-Staaken E-4/20 . Commercial aircraft development during the 1920s and 1930s focused on monoplane designs using Radial engines . Some were produced as single copies or in small quantity such as
4176-522: The 2000s. The Boeing 787 , first flown in 2009, was the first commercial aircraft with 50% of its structure weight made of carbon-fiber composites, along with 20% aluminium and 15% titanium: the material allows for a lower-drag, higher wing aspect ratio and higher cabin pressurization; the competing Airbus A350 , flown in 2013, is 53% carbon-fiber by structure weight. It has a one-piece carbon fiber fuselage, said to replace "1,200 sheets of aluminium and 40,000 rivets." The 2013 Bombardier CSeries have
4292-456: The Air Ministry put forward a plan that its production be stopped after the initial order for 310, after which Supermarine would build Bristol Beaufighters . The managements of Supermarine and Vickers were able to convince the Air Ministry that production problems could be overcome, and a further order was placed for 200 Spitfires on 24 March 1938. The two orders covered the K, L, and N prefix serial numbers. The first production Spitfire came off
4408-604: The Air Ministry released specification F7/30 , calling for a modern fighter capable of a flying speed of 250 mph (400 km/h) to replace the Gloster Gauntlet biplane. R. J. Mitchell designed the Supermarine Type 224 to fill this role in competition with the Blackburn F.3 and Westland F.7/30 and privately funded designs from Gloster. The 224 was an open-cockpit monoplane with bulky gull wings and
4524-518: The Albatros firm's concept were used by both Hannoversche Waggonfabrik for their light two-seat CL.II through CL.V designs, and by Siemens-Schuckert for their later Siemens-Schuckert D.III and higher-performance D.IV biplane fighter designs. The Albatros D.III construction was of much less complexity than the patented LFG Wickelrumpf concept for their outer skinning. German engineer Hugo Junkers first flew all-metal airframes in 1915 with
4640-447: The Bf 109E, were unable to simply nose down into a steep dive. This meant a Luftwaffe fighter could simply "bunt" into a high-power dive to escape an attack, leaving the Spitfire behind, as its fuel was forced out of the carburettor by negative "g" . RAF fighter pilots soon learned to "half-roll" their aircraft before diving to pursue their opponents. Airframe Airframe design is
4756-726: The Castle Bromwich plant to his ministry. Beaverbrook immediately sent in experienced management staff and workers from Supermarine, and gave control of the factory to Vickers-Armstrongs. Although resolving the problems took time, in June 1940, 10 Mk IIs were built; 23 rolled out in July, 37 in August, and 56 in September. By the time production ended at Castle Bromwich in June 1945, a total of 12,129 Spitfires (921 Mk IIs, 4,489 Mk Vs, 5,665 Mk IXs, and 1,054 Mk XVIs ) had been built, at
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4872-518: The First World War. In 1916, L. Brequet designed a reconnaissance bomber that marked the initial use of aluminum in the working structure of an airplane. By war’s end, the Allies and Germany employed aluminum alloys for the structural framework of fuselage and wing assemblies. The aircraft airframe has been the most demanding application for aluminum alloys; to chronicle the development of
4988-631: The German/Austrian Taube monoplanes . These used hybrid wood and metal structures. By the 1915/16 timeframe, the German Luft-Fahrzeug-Gesellschaft firm had devised a fully monocoque all-wood structure with only a skeletal internal frame, using strips of plywood laboriously "wrapped" in a diagonal fashion in up to four layers, around concrete male molds in "left" and "right" halves, known as Wickelrumpf (wrapped-body) construction - this first appeared on
5104-552: The Goshawk led to the adoption of a cooling system which used 100% glycol . The radiators were housed in a new radiator-duct designed by Fredrick Meredith of the Royal Aircraft Establishment (RAE) at Farnborough, Hampshire . This used the cooling air to generate thrust , greatly reducing the net drag produced by the radiators. In turn, the leading-edge structure lost its function as a condenser, but it
5220-536: The Italian Savoia-Marchetti S.56 , the 1931 Budd BB-1 Pioneer experimental flying boat was constructed of corrosion-resistant stainless steel assembled with newly developed spot welding by U.S. railcar maker Budd Company . The original Junkers corrugated duralumin-covered airframe philosophy culminated in the 1932-origin Junkers Ju 52 trimotor airliner, used throughout World War II by
5336-594: The Mach 3.1 North American XB-70 Valkyrie used brazed stainless steel honeycomb panels and titanium but was cancelled by the time it flew in 1964. A computer-aided design system was developed in 1969 for the McDonnell Douglas F-15 Eagle , which first flew in 1974 alongside the Grumman F-14 Tomcat and both used boron fiber composites in the tails; less expensive carbon fiber reinforced polymer were used for wing skins on
5452-571: The Nazi German Luftwaffe for transport and paratroop needs. Andrei Tupolev's designs in Joseph Stalin 's Soviet Union designed a series of all-metal aircraft of steadily increasing size culminating in the largest aircraft of its era, the eight-engined Tupolev ANT-20 in 1934, and Donald Douglas ' firms developed the iconic Douglas DC-3 twin-engined airliner in 1936. They were among the most successful designs to emerge from
5568-471: The Rolls-Royce Merlin engine at £2,000, followed by the wings at £1,800 a pair, guns and undercarriage, both at £800 each, and the propeller at £350. In 1935, the Air Ministry approached Morris Motors Limited to ask how quickly their Cowley plant could be turned to aircraft production. In 1936, this informal request for major manufacturing facilities was replaced by a formal scheme, known as
5684-730: The Second World War. In the mid-1930s, aviation design teams worldwide began developing a new generation of fighter aircraft. The French Dewoitine D.520 and the German Messerschmitt Bf 109 , for example, were designed to take advantage of new techniques of monocoque construction, and the availability of new, high-powered, liquid-cooled, in-line aero engines. They also had refinements such as retractable undercarriages, fully enclosed cockpits, and low-drag, all-metal wings. These advances had been introduced on civil airliners years before, but were slow to be adopted by
5800-556: The Southampton area. To this end, the British government requisitioned the likes of Vincent's Garage in Station Square, Reading , which later specialised in manufacturing Spitfire fuselages, and Anna Valley Motors, Salisbury , which was to become the sole producer of the wing leading-edge fuel tanks for photo-reconnaissance Spitfires. A purpose-built works, specialising in manufacturing fuselages and installing engines,
5916-589: The Spitfire's development through many variants , from the Mk 1 to the Rolls-Royce Griffon-engined Mk 24, using several wing configurations and guns. The original airframe was designed to be powered by a Rolls-Royce Merlin engine producing 1,030 hp (768 kW). It was strong enough and adaptable enough to use increasingly powerful Merlins, and in later marks, Rolls-Royce Griffon engines producing up to 2,340 hp (1,745 kW). As
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#17327978527826032-496: The Spitfire's distinctive elliptical wing (designed by Beverley Shenstone ) with innovative sunken rivets to have the thinnest possible cross-section, achieving a potential top speed greater than that of several contemporary fighter aircraft, including the Hawker Hurricane . Mitchell continued to refine the design until his death in 1937, whereupon his colleague Joseph Smith took over as chief designer. Smith oversaw
6148-559: The UK over the North Sea , and Germany did not have any single-engine fighters with the range to accompany them. To carry out the mission of home defence, the design was intended to allow the Spitfire to climb quickly to intercept enemy bombers. The Spitfire's airframe was complex. The streamlined, semi-monocoque , duralumin-skinned fuselage had a number of compound curves built up over a skeleton of 19 formers , also known as frames. These started from frame number one, immediately behind
6264-465: The United Kingdom in an effort to thank medical & health workers for their on-going fight against the virus. Simultaneously, the general public was able to donate money to 'The NHS Spitfire' project, with a nominated name from each donation being hand-written onto the Spitfire. As of January 2021, the project has raised over £130,000.00, with all funds going to NHS Charities Together . Over
6380-524: The all-metal, cantilever -wing, stressed-skin monoplane Junkers J 1 made of steel . It developed further with lighter weight duralumin , invented by Alfred Wilm in Germany before the war; in the airframe of the Junkers D.I of 1918, whose techniques were adopted almost unchanged after the war by both American engineer William Bushnell Stout and Soviet aerospace engineer Andrei Tupolev , proving to be useful for aircraft up to 60 meters in wingspan by
6496-542: The altered aerodynamics, culminating in those of the Mk 22/24 series, which were 25% larger in area than those of the Mk I. As the Spitfire gained more power and was able to manoeuvre at higher speeds, the possibility that pilots would encounter aileron reversal increased, and the Supermarine design team set about redesigning the wings to counter this. The original wing design had a theoretical aileron reversal speed of 580 mph (500 kn; 930 km/h), which
6612-423: The assembly line in mid-1938 and was flown by Jeffrey Quill on 15 May 1938, almost 24 months after the initial order. The final cost of the first 310 aircraft, after delays and increased programme costs, came to £1,870,242 or £1,533 more per aircraft than originally estimated. A production aircraft cost about £9,500. The most expensive components were the hand-fabricated and finished fuselage at roughly £2,500, then
6728-454: The bending loads on the main-spar during landing. Ahead of the spar, the thick-skinned leading edge of the wing formed a strong and rigid, D-shaped box, which took most of the wing loads. At the time the wing was designed, this D-shaped leading edge was intended to house steam condensers for the evaporative cooling system intended for the PV-XII. Constant problems with the evaporative system in
6844-478: The best known were the US C-47 Skytrain , B-17 Flying Fortress , B-25 Mitchell and P-38 Lightning , and British Vickers Wellington that used a geodesic construction method, and Avro Lancaster , all revamps of original designs from the 1930s. The first jets were produced during the war but not made in large quantity. Due to wartime scarcity of aluminium, the de Havilland Mosquito fighter-bomber
6960-402: The company in the Southampton area. Quill devised the standard testing procedures, which with variations for specific aircraft designs operated from 1938. Alex Henshaw , chief test pilot at Castle Bromwich from 1940, was placed in charge of testing all Spitfires built at that factory. He co-ordinated a team of 25 pilots and assessed all Spitfire developments. Between 1940 and 1946, Henshaw flew
7076-656: The difficulties that the airframe industry and its airline customers can experience when adopting new technology . The incident bears comparison with the Airbus A300 crash on takeoff of the American Airlines Flight 587 in 2001, after its vertical stabilizer broke away from the fuselage , called attention to operation, maintenance and design issues involving composite materials that are used in many recent airframes. The A300 had experienced other structural problems but none of this magnitude. As
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#17327978527827192-405: The end of each main wing assembly. When the Spitfire took on a role as a high-altitude fighter (Marks VI and VII and some early Mk VIIIs), the standard wing tips were replaced by extended, "pointed" tips which increased the wingspan from 36 ft 10 in (11.23 m) to 40 ft 2 in (12.24 m). The other wing-tip variation, used by several Spitfire variants, was the "clipped" wing;
7308-518: The era through the use of all-metal airframes. In 1937, the Lockheed XC-35 was specifically constructed with cabin pressurization to undergo extensive high-altitude flight tests, paving the way for the Boeing 307 Stratoliner , which would be the first aircraft with a pressurized cabin to enter commercial service. During World War II , military needs again dominated airframe designs. Among
7424-513: The fabric covering of the ailerons "ballooned" at high speeds, adversely affecting the aerodynamics. Replacing the fabric covering with light alloy dramatically improved the ailerons at high speed. During the Battle of Britain, pilots found the Spitfire's ailerons were far too heavy at high speeds, severely restricting lateral manoeuvres such as rolls and high-speed turns, which were still a feature of air-to-air combat. The Spitfire had detachable wing tips which were secured by two mounting points at
7540-567: The final approach and for landing, and the pilot was to retract them before taxiing. The ellipse also served as the design basis for the Spitfire's fin and tailplane assembly, once again exploiting the shape's favourable aerodynamic characteristics. Both the elevators and rudder were shaped so that their centre of mass was shifted forward, reducing control-surface flutter. The longer noses and greater propeller-wash resulting from larger engines in later models necessitated increasingly larger vertical, and later, horizontal tail surfaces to compensate for
7656-434: The first Spitfires were being built in June 1940, the factory was still incomplete, and suffering from personnel problems. The Spitfire's stressed-skin construction required precision engineering skills and techniques that were beyond the capabilities of the local labour force, and some time was required to retrain them. Difficulties arose with management, who ignored Supermarine's tooling and drawings in favour of their own, and
7772-474: The focal points for these workshops: Southampton's Eastleigh Airport; Salisbury and the High Post and Chattis Hill aerodromes; Trowbridge and RAF Keevil ; and Reading's Henley and Aldermaston aerodromes. Completed Spitfires were delivered to the airfields on Commer " Queen Mary " low-loader trailers, there to be fully assembled, tested, then passed on to the RAF. An experimental factory at Newbury
7888-572: The following aircraft to the air: The Aircraft Restoration Company currently own, maintain or operate the following warbird aircraft: In response to the Coronavirus pandemic in 2020, the Aircraft Restoration Company painted the words 'THANK U NHS' on the underside of their Spitfire PR Mk XI PL983 "L". Over the course of 4 months the Spitfire completed a number of flight routes, flying over 250 NHS and HSC sites across
8004-428: The four main fuselage longerons to the rest of the airframe. Behind the bulkhead were five U-shaped half-frames which accommodated the fuel tanks and cockpit. The rear fuselage started at the 11th frame, to which the pilot's seat and (later) armour plating were attached, and ended at the 19th, which was mounted at a slight forward angle just forward of the fin. Each of these nine frames was oval, reducing in size towards
8120-497: The fuel tankage dropped to 75 gallons from 94. On 5 March 1936, the prototype ( K5054 ) , fitted with a fine-pitch propeller to give more power for takeoff, took off on its first flight from Eastleigh Aerodrome (later Southampton Airport). At the controls was Captain Joseph "Mutt" Summers , chief test pilot for Vickers, who is quoted as saying, "don't touch anything" on landing. This eight-minute flight came four months after
8236-477: The fuselage, wings, and tailplane was secured by dome-headed rivets, and in critical areas such as the wing forward of the main spar where an uninterrupted airflow was required, with flush rivets. From February 1943 flush riveting was used on the fuselage, affecting all Spitfire variants. In some areas, such as at the rear of the wing and the lower tailplane skins, the top was riveted and the bottom fixed by brass screws which tapped into strips of spruce bolted to
8352-678: The high-performance aircraft designed since 1945 have made extensive use of skin structures machined from thick plate and extrusions, precluding the use of alclad exterior skins. Maintenance requirements increased as a result, and these stimulated research and development programs seeking higher-strength alloys with improved resistance to corrosion without cladding. Aluminum alloy castings traditionally have been used in nonstructural airplane hardware, such as pulley brackets, quadrants, doublers, clips and ducts. They also have been employed extensively in complex valve bodies of hydraulic control systems. The philosophy of some aircraft manufacturers still
8468-502: The high-strength alloys is also to record the development of airframes. Duralumin , the first high-strength, heat treatable aluminum alloy, was employed initially for the framework of rigid airships , by Germany and the Allies during World War I. Duralumin was an aluminum-copper-magnesium alloy; it was originated in Germany and developed in the United States as Alloy 17S-T (2017-T4). It was utilized primarily as sheet and plate. Alloy 7075-T6 (70,000-psi yield strength), an Al-Zn-Mg-Cu alloy,
8584-403: The high-strength alloys utilized have low weldability and low weld-joint efficiencies. Some of the alloys, such as 2024-T4, also have their corrosion resistance lowered in the heat-affected zone if left in the as-welded condition. The improved welding processes and higher-strength weldable alloys developed during the past decade offer new possibilities for welded primary structures. For example,
8700-493: The largest number of Spitfires and Hurricanes in the world. ARCo specialises in the major and minor maintenance of the RAF BBMF aircraft, including Avro Lancaster , DC-3 Dakota and De Havilland Chipmunks . The company now uses its expertise to also offer experience flights in its historic aircraft, through their in-house team Aerial Collective Duxford. The Aircraft Restoration Company / Historic Flying Limited have returned
8816-646: The later marks, although they were faster than the earlier ones, were also much heavier, so did not handle so well. You did not have such positive control over them. One test of manoeuvrability was to throw her into a flick-roll and see how many times she rolled. With the Mark II or the Mark V one got two-and-a-half flick-rolls, but the Mark IX was heavier and you got only one-and-a-half. With the later and still heavier versions, one got even less. The essence of aircraft design
8932-533: The light, strong and streamlined monocoque fuselage formed of thin plywood layers over a circular frame, achieving 210 km/h (130 mph). Many early developments were spurred by military needs during World War I . Well known aircraft from that era include the Dutch designer Anthony Fokker 's combat aircraft for the German Empire 's Luftstreitkräfte , and U.S. Curtiss flying boats and
9048-571: The limits of its performance. This washout was first featured in the wing of the Type 224, and became a consistent feature in subsequent designs leading to the Spitfire. The complex wing design, especially the precision required to manufacture the vital spar and leading-edge structures, caused some major delays in the production of the Spitfire at first. The problems increased when the work was put out to subcontractors, most of whom had never dealt with metal-structured, high-speed aircraft. By June 1939, most of these problems had been resolved, and production
9164-466: The lower ribs. The removable wing tips were made up of duralumin-skinned spruce formers. At first, the ailerons, elevators, and rudder were fabric-covered, but once combat experience showed that fabric-covered ailerons were impossible to use at high speeds a light alloy replaced the fabric, enhancing control throughout the speed range. In 1934, Mitchell and the design staff decided to use a semi-elliptical wing shape to solve two conflicting requirements;
9280-451: The maiden flight of the contemporary Hurricane. K5054 was fitted with a new propeller, and Summers flew the aircraft on 10 March 1936; during this flight, the undercarriage was retracted for the first time. After the fourth flight, a new engine was fitted, and Summers left the test flying to his assistants, Jeffrey Quill and George Pickering. They soon discovered that the Spitfire was a very capable aircraft, but not perfect. The rudder
9396-536: The main spar, preventing the wings from twisting. Mitchell has sometimes been accused of copying the wing shape of the Günter brothers -designed Heinkel He 70 , which first flew in 1932, but as Beverley Shenstone , the aerodynamicist on Mitchell's team, explained: "Our wing was much thinner and had quite a different section to that of the Heinkel. In any case, it would have been simply asking for trouble to have copied
9512-566: The method has not yet been developed extensively in the aerospace industry. Adhesive bonding is a common method of joining in both primary and secondary structures. Its selection is dependent on the design philosophy of the aircraft manufacturer. It has proven satisfactory in attaching stiffeners, such as hat sections to sheet, and face sheets to honeycomb cores . Also, adhesive bonding has withstood adverse exposures such as sea-water immersion and atmospheres. Fusion welded aluminum primary structures in airplanes are virtually nonexistent, because
9628-457: The military, who favoured the biplane's simplicity and manoeuvrability. Mitchell's design aims were to create a well-balanced, high-performance fighter aircraft capable of fully exploiting the power of the Merlin engine, while being relatively easy to fly. At the time, with France as an ally , and Germany thought to be the most likely future opponent, no enemy fighters were expected to appear over Great Britain. German bombers would have to fly to
9744-403: The necessary strength. But near the root the wing had to be thick enough to accommodate the retracted undercarriages and the guns ... Mitchell was an intensely practical man ... The ellipse was simply the shape that allowed us the thinnest possible wing with room inside to carry the necessary structure and the things we wanted to cram in. And it looked nice. The wing section used was from
9860-617: The new wing could give an increase in speed of 55 mph (48 kn; 89 km/h) over the Spitfire Mk 21. The new wing was initially fitted to a Spitfire Mk XIV. Later, a new fuselage was designed, with the new fighter becoming the Supermarine Spiteful . The Rolls Royce engine's designers deliberately chose a carburettor for the Merlin engine: Sir Stanley Hooker explained in his autobiography that "the Germans paid
9976-439: The next month, other raids were mounted, until, on 26 September 1940, both factories were destroyed, with 92 people killed and a large number injured. Most of the casualties were experienced aircraft-production workers. Fortunately for the future of the Spitfire, many of the production jigs and machine tools had already been relocated by 20 September, and steps were being taken to disperse production to small facilities throughout
10092-399: The propeller unit, to the tail unit attachment frame. The first four frames supported the glycol header tank and engine cowlings. Frame five, to which the engine bearers were secured, supported the weight of the engine and its accessories. This was a strengthened double frame which also incorporated the fireproof bulkhead, and in later versions of the Spitfire, the oil tank. This frame also tied
10208-514: The prototype for the RAF. He had been given orders to fly the aircraft and then to make his report to the Air Ministry on landing. Edwardes-Jones' report was positive; his only request was that the Spitfire be equipped with an undercarriage position indicator. A week later, on 3 June 1936, the Air Ministry placed an order for 310 Spitfires, at a cost of £ 1,395,000. before the A&AEE had issued any formal report. Interim reports were later issued on
10324-404: The radiator under the starboard wing was halved in size and the intercooler radiator housed alongside. Under the port wing, a new radiator fairing housed a square oil cooler alongside of the other half-radiator unit. The two radiator flaps were now operated automatically by a thermostat . Another wing feature was its washout . The trailing edge of the wing twisted slightly upward along its span,
10440-432: The rated altitude of one or both supercharger blowers. Then I would make a careful check of the power output from the engine, calibrated for height and temperature ... If all appeared satisfactory, I would then put her into a dive at full power and 3,000 rpm, and trim her to fly hands and feet off at 460 mph (740 km/h) IAS (Indicated Air Speed). Personally, I never cleared a Spitfire unless I had carried out
10556-538: The same time removing bomb carry requirement and reducing fuel capacity. Mitchell foresaw no problem adding the guns and welcomed the reduction which would reduce weight. A specification for an eight gun fighter, F5/34 had come from a recommendation by Squadron Leader Ralph Sorley of the Operational Requirements section at the Air Ministry. In the redesign the change was made from Vickers machine guns to .303 in (7.7 mm) Brownings) , and
10672-469: The sheet. Electrolytic protection , present under wet or moist conditions, is based on the appreciably higher electrode potential of commercial-purity aluminum compared to alloy 2017 or 2024 in the T3 or T4 temper. When 7075-T6 and other Al-Zn-Mg-Cu alloys appeared, an aluminum-zinc cladding alloy 7072 was developed to provide a relative electrode potential sufficient to protect the new strong alloys. However,
10788-402: The skin needs moderately high yield strength and hardness to minimize ground damage from stones, debris, mechanics’ tools, and general handling. Other primary factors involved in selecting an alloy for this application are corrosion resistance, cost, and appearance. Alloys 6061-T6 and alclad 2024-T3 are the primary choices. Skin sheet on light airplanes of recent design and construction generally
10904-488: The standard wing tips were replaced by wooden fairings which reduced the span by 3 ft 6 in (1.07 m). The wing tips used spruce formers for most of the internal structure with a light alloy skin attached using brass screws. The light alloy split flaps at the trailing edge of the wing were also pneumatically operated via a finger lever on the instrument panel. Only two positions were available; fully up or fully down (85°). Flaps were normally lowered only during
11020-430: The tail, and incorporated several lightening holes to reduce their weight as much as possible without weakening them. The U-shaped frame 20 was the last frame of the fuselage proper and the frame to which the tail unit was attached. Frames 21, 22 and 23 formed the fin; frame 22 incorporated the tailwheel opening and frame 23 was the rudder post. Before being attached to the main fuselage, the tail unit frames were held in
11136-452: The theoretical aileron reversal speed was increased to 825 mph (717 kn; 1,328 km/h). Alongside the redesigned wing, Supermarine also experimented with the original wing, raising the leading edge by 1 inch (25 mm), with the hope of improving pilot view and reducing drag. This wing was tested on a modified F Mk 21, also called the F Mk 23, (sometimes referred to as "Valiant" rather than "Spitfire"). The increase in performance
11252-452: The twentieth century progressed, aluminum became an essential metal in aircraft. The cylinder block of the engine that powered the Wright brothers’ plane at Kitty Hawk in 1903 was a one-piece casting in an aluminum alloy containing 8% copper; aluminum propeller blades appeared as early as 1907; and aluminum covers, seats, cowlings, cast brackets, and similar parts were common by the beginning of
11368-506: The weldability and strength of alloys 2219 and 7039, and the brazeability and strength of X7005, open new avenues for design and manufacture of aircraft structures. Light aircraft have airframes primarily of all-aluminum semi-monocoque construction, however, a few light planes have tubular truss load-carrying construction with fabric or aluminum skin, or both. Aluminum skin is normally of the minimum practical thickness: 0.015 to 0.025 in. Although design strength requirements are relatively low,
11484-405: The wing needed to be thin to avoid creating too much drag , but it had to be thick enough to house the retractable undercarriage, armament, and ammunition. An elliptical planform is the most efficient aerodynamic shape for an untwisted wing, leading to the lowest amount of induced drag . The ellipse was skewed so that the centre of pressure, which occurs at the quarter- chord position, aligned with
11600-454: The workforce continually threatened strikes or "slow downs" until their demands for higher wages were met. In spite of promises that the factory would be producing 60 per week starting in April, by May 1940, Castle Bromwich had not yet built its first Spitfire. On 17 May, Minister of Aircraft Production Lord Beaverbrook telephoned Lord Nuffield and manoeuvred him into handing over control of
11716-417: The world's first jet airliner , the de Havilland Comet , first flew in 1949. Early models suffered from catastrophic airframe metal fatigue , causing a series of widely publicised accidents. The Royal Aircraft Establishment investigation at Farnborough Airport founded the science of aircraft crash reconstruction. After 3000 pressurisation cycles in a specially constructed pressure chamber, airframe failure
11832-481: The years, the Aircraft Restoration Company has worked or featured on numerous TV and film projects, often providing aircraft, pilots, historical advice and expertise on aerial coordinating. Works include: Supermarine Spitfire The Supermarine Spitfire is a British single-seat fighter aircraft used by the Royal Air Force and other Allied countries before, during, and after World War II . It
11948-466: Was built at Star Road, Caversham in Reading. The drawing office in which all Spitfire designs were drafted was moved to Hursley Park , near Winchester . This site also had an aircraft assembly hangar where many prototype and experimental Spitfires were assembled, but since it had no associated aerodrome, no Spitfires ever flew from Hursley. Four towns and their satellite airfields were chosen to be
12064-669: Was built from wood—plywood facings bonded to a balsawood core and formed using molds to produce monocoque structures, leading to the development of metal-to-metal bonding used later for the de Havilland Comet and Fokker F27 and F28 . Postwar commercial airframe design focused on airliners , on turboprop engines, and then on jet engines . The generally higher speeds and tensile stresses of turboprops and jets were major challenges. Newly developed aluminium alloys with copper , magnesium and zinc were critical to these designs. Flown in 1952 and designed to cruise at Mach 2 where skin friction required its heat resistance,
12180-513: Was found to be due to stress concentration, a consequence of the square shaped windows. The windows had been engineered to be glued and riveted, but had been punch riveted only. Unlike drill riveting, the imperfect nature of the hole created by punch riveting may cause the start of fatigue cracks around the rivet. The Lockheed L-188 Electra turboprop, first flown in 1957 became a costly lesson in controlling oscillation and planning around metal fatigue . Its 1959 crash of Braniff Flight 542 showed
12296-489: Was introduced in 1943. Since then, most aircraft structures have been specified in alloys of this type. The first aircraft designed in 7075-T6 was the Navy’s P2V patrol bomber . A higher-strength alloy in the same series, 7178-T6 (78,000-psi yield strength), was developed in 1951; it has not generally displaced 7075-T6, which has superior fracture toughness. Alloy 7178-T6 is used primarily in structural members where performance
12412-526: Was later adapted to house integral fuel tanks of various sizes — a feature patented by Vickers-Supermarine in 1938. The airflow through the main radiator was controlled by pneumatic exit flaps. In early marks of the Spitfire (Mk I to Mk VI), the single flap was operated manually using a lever to the left of the pilot's seat. When the two-stage Merlin was introduced in the Spitfire Mk IX , the radiators were split to make room for an intercooler radiator;
12528-497: Was later named the "Merlin". In November 1934, Mitchell, with the backing of Supermarine's owner Vickers-Armstrong , started detailed design work on this refined version of the Type 300. On 1 December 1934, the Air Ministry issued contract AM 361140/34, providing £10,000 for the construction of Mitchell's improved Type 300 design. In April 1935 Ralph Sorley spoke to Mitchell about the new specification F10/35 which called for armament of at least six and preferably eight guns while at
12644-488: Was minimal and this experiment was abandoned. Supermarine developed a new laminar-flow wing based on new aerofoil profiles developed by the National Advisory Committee for Aeronautics in the United States, with the objective of reducing drag and improving performance. These laminar-flow airfoils were the Supermarine 371-I used at the root and the 371-II used at the tip. Supermarine estimated that
12760-484: Was no longer held up by a lack of wings. All the main flight controls were originally metal structures with fabric covering. Designers and pilots felt that having ailerons which required a degree of effort to move at high speed would avoid unintended aileron reversal, throwing the aircraft around and potentially pulling the wings off. Air combat was also felt to take place at relatively low speeds and high-speed manoeuvring would be physically impossible. Flight tests showed
12876-579: Was oversensitive, and the top speed was just 330 mph (528 km/h), little faster than Sydney Camm 's new Merlin-powered Hurricane. A new and better-shaped, two-bladed, wooden propeller allowed the Spitfire to reach 348 mph (557 km/h) in level flight in mid-May, when Summers flew K5054 to RAF Martlesham Heath and handed the aircraft over to Squadron Leader Anderson of the Aeroplane & Armament Experimental Establishment (A&AEE). Here, Flight Lieutenant Humphrey Edwardes-Jones took over
12992-451: Was somewhat lower than that of some contemporary fighters. The Royal Aircraft Establishment noted that, at 400 mph (350 kn; 640 km/h) indicated airspeed , roughly 65% of aileron effectiveness was lost due to wing twist. The new wing of the Spitfire F Mk 21 and its successors was designed to help alleviate this problem. Its stiffness was increased by 47%, and a new aileron design using piano hinges and geared trim tabs meant
13108-463: Was the only British fighter produced continuously throughout the war. The Spitfire remains popular among enthusiasts. Around 70 remain airworthy , and many more are static exhibits in aviation museums throughout the world. The Spitfire was designed as a short-range, high-performance interceptor aircraft by R. J. Mitchell , chief designer at Supermarine Aviation Works, which operated as a subsidiary of Vickers-Armstrong from 1928. Mitchell developed
13224-445: Was the subject of a Luftwaffe daylight raid, but the bombs missed their target and hit a nearby school. All production aircraft were flight tested before delivery. During the Second World War, Jeffrey Quill was Vickers Supermarine's chief test pilot, in charge of flight testing all aircraft types built by Vickers Supermarine. He oversaw a group of 10 to 12 pilots responsible for testing all developmental and production Spitfires built by
13340-419: Was to subcontract the work. Although outside contractors were supposed to be involved in manufacturing many important Spitfire components, especially the wings, Vickers-Armstrongs (the parent company) was reluctant to see the Spitfire being manufactured by outside concerns, and was slow to release the necessary blueprints and subcomponents. As a result of the delays in getting the Spitfire into full production,
13456-532: Was used in the European , Mediterranean , Pacific , and South-East Asian theatres. Much loved by its pilots, the Spitfire operated in several roles, including interceptor, photo-reconnaissance, fighter-bomber, and trainer, and it continued to do so until the 1950s. The Seafire was an aircraft carrier–based adaptation of the Spitfire, used in the Fleet Air Arm from 1942 until the mid-1950s. In 1931,
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