Republic P-47 Thunderbolt
The Republic P-47 Thunderbolt was a World War II era fighter aircraft produced by the United States from 1941 through 1945. Its primary armament was eight.50-caliber machine guns and in the fighter-bomber ground-attack role it could carry five-inch rockets or a bomb load of 2,500 pounds. When loaded the P-47 weighed up to eight tons making it one of the heaviest fighters of the war; the P-47 was designed around the powerful Pratt & Whitney R-2800 Double Wasp engine, used by two U. S. Navy/U. S. Marine Corps fighters, the Grumman F6F Hellcat and the Vought F4U Corsair; the Thunderbolt was effective as a short-to-medium range escort fighter in high-altitude air-to-air combat and ground attack in both the World War II European and Pacific theaters. The P-47 was one of the main United States Army Air Forces fighters of World War II, served with Allied air forces including France and Russia. Mexican and Brazilian squadrons fighting alongside the U. S. flew the P-47. The armored cockpit was roomy and comfortable and the bubble canopy introduced on the P-47D offered good visibility.
A present-day U. S. ground-attack aircraft, the Fairchild Republic A-10 Thunderbolt II, takes its name from the P-47. The P-47 Thunderbolt was a design of Georgian immigrant Alexander Kartveli, was to replace the Seversky P-35, developed earlier by Russian immigrant Alexander P. de Seversky. Both had fled from their homeland to escape the Bolsheviks. In 1939, Republic Aviation designed the AP-4 demonstrator powered by a Pratt & Whitney R-1830 radial engine with a belly-mounted turbocharger. A small number of Republic P-43 Lancers were built but Republic had been working on an improved P-44 Rocket with a more powerful engine, as well as on the AP-10 fighter design; the latter was a lightweight aircraft powered by the Allison V-1710 liquid-cooled V-12 engine and armed with eight.50 in M2 Browning machine guns. The United States Army Air Corps backed the project and gave it the designation XP-47. In the spring of 1940, Republic and the USAAC concluded that the XP-44 and the XP-47 were inferior to Luftwaffe fighters.
Republic tried to improve the design, proposing the XP-47A but this failed. Kartveli designed a much larger fighter, offered to the USAAC in June 1940; the Air Corps ordered a prototype in September as the XP-47B. The XP-47A, which had little in common with the new design, was abandoned; the XP-47B was of all-metal construction with elliptical wings, with a straight leading edge, swept back. The air-conditioned cockpit was roomy and the pilot's seat was comfortable—"like a lounge chair", as one pilot put it; the canopy doors hinged upward. Main and auxiliary self-sealing fuel tanks were placed under the cockpit, giving a total fuel capacity of 305 U. S. gal. Power came from a Pratt & Whitney R-2800 Double Wasp two-row 18-cylinder radial engine producing 2,000 hp —the same engine that would power the prototype Vought XF4U-1 fighter to just over 400 mph in October 1940—with the Double Wasp on the XP-47B turning a four-bladed Curtiss Electric constant-speed propeller of 146 in in diameter; the loss of the AP-4 prototype to an engine fire ended Kartveli's experiments with tight-fitting cowlings, so the engine was placed in a broad cowling that opened at the front in a "horse collar"-shaped ellipse.
The cowling admitted cooling air for the engine and right oil coolers, the turbosupercharger intercooler system. The engine exhaust gases were routed into a pair of wastegate-equipped pipes that ran along each side of the cockpit to drive the turbosupercharger turbine at the bottom of the fuselage, about halfway between cockpit and tail. At full power, the pipes glowed red at the turbine spun at 21,300 rpm; the complicated turbosupercharger system with its ductwork gave the XP-47B a deep fuselage, the wings had to be mounted in a high position. This was difficult since long-legged main landing gear struts were needed to provide ground clearance for the enormous propeller. To reduce the size and weight of the undercarriage struts and so that wing-mounted machine guns could be fitted, each strut was fitted with a mechanism by which it telescoped out 9 in when extended; the XP-47B was heavy compared with contemporary single-engined fighters, with an empty weight of 9,900 lb, or 65 per cent more than the YP-43.
Kartveli said, "It will be a dinosaur, but it will be a dinosaur with good proportions". The armament was eight.50 caliber "light-barrel" Browning AN/M2 machine guns, four in each wing. The guns were staggered to allow feeding from side-by-side ammunition boxes, each with 350 rounds. All eight guns gave the fighter a combined rate of fire of 100 rounds per second; the XP-47B first flew on 6 May 1941 with Lowry P. Brabham at the controls. Although there were minor problems, such as some cockpit smoke that turned out to be due to an oil drip, the aircraft proved impressive in its early trials, it was lost in an accident on 8 August 1942 but before that mishap, the prototype had achieved a level speed of 412 mph at 25,800 ft altitude and had demonstrated a climb from sea level to 15,000 ft in five minutes. The XP-47B gave the newly reorganized United States Army Air Forces cause for both optimism and apprehension. While possessing good performance and firepower, the XP-47B had its share of teething problems: Its sheer size and limited ground-propeller clearance in a fuselage-level attitude made for challenging takeoffs which required long runways—the pilot had to hold the tail low until considerable speed was attained on the initial run.
The sideways-opening can
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which includes medium-density fibreboard and particle board. All plywoods bind wood fibre sheets to form a composite material; this alternation of the grain is called cross-graining and has several important benefits: it reduces the tendency of wood to split when nailed in at the edges. There is an odd number of plies, so that the sheet is balanced—this reduces warping; because plywood is bonded with grains running against one another and with an odd number of composite parts, it has high stiffness perpendicular to the grain direction of the surface ply. Smaller and lower-quality plywoods may only have their plies arranged at right angles to each other; some better-quality plywood products will by design have five plies in steps of 45 degrees, giving strength in multiple axes.
The word ply derives from the French verb plier, "to fold", from the Latin verb plico, from the ancient Greek verb πλέκω. In 1797 Samuel Bentham applied for patents covering several machines to produce veneers. In his patent applications, he described the concept of laminating several layers of veneer with glue to form a thicker piece – the first description of what we now call plywood. Bentham was a British naval engineer with many shipbuilding inventions to his credit. Veneers at the time of Bentham were rift sawn or quarter sawn. About fifty years Immanuel Nobel, father of Alfred Nobel, realized that several thinner layers of wood bonded together would be stronger than a single thick layer of wood. Understanding the industrial potential of laminated wood, he invented the rotary lathe. There is little record of the early implementation of the rotary lathe and the subsequent commercialization of plywood as we know it today, but in its 1870 edition, the French dictionary Robert describes the process of rotary lathe veneer manufacturing in its entry Déroulage.
One can thus presume that rotary lathe plywood manufacturer was an established process in France in the 1860s. Plywood was introduced into the United States in 1865 and industrial production started shortly after. In 1928, the first standard-sized 4 ft by 8 ft plywood sheets were introduced in the United States for use as a general building material. Artists use plywood as a support for easel paintings to replace traditional cardboard. Ready-made artist boards for oil painting in three-layered plywood were produced and sold in New York as early as 1880. In India Plywood is known as "Kitply" after the brand which pioneered the concept of "Branded Plyboards" in the early 70's. A typical plywood panel has face veneers of a higher grade than the core veneers; the principal function of the core layers is to increase the separation between the outer layers where the bending stresses are highest, thus increasing the panel's resistance to bending. As a result, thicker panels can span greater distances under the same loads.
In bending, the maximum stress occurs in the outermost layers, one in tension, the other in compression. Bending stress decreases from the maximum at the face layers to nearly zero at the central layer. Shear stress, by contrast, is higher in the center of the panel, at the outer fibres. Different varieties of plywood exist for different applications: Softwood plywood is made either of cedar, Douglas fir or spruce and fir or redwood and is used for construction and industrial purposes; the most common dimension is 1.2 by 2.4 metres or the larger imperial dimension of 4 feet × 8 feet. Plies vary in thickness from 1.4 mm to 4.3 mm. The number of plies --, always odd -- depends on the grade of the sheet. Roofing can use the thinner 5⁄8-inch plywood. Subfloors are at least 3⁄4 inch thick, the thickness depending on the distance between floor joists. Plywood for flooring applications is tongue and groove. T&G plywood is found in the 1⁄2-to-1-inch range. Hardwood plywood is used for demanding end uses.
Hardwood plywood is characterized by its excellent strength and resistance to creep. It has a high planar shear strength and impact resistance, which make it suitable for heavy-duty floor and wall structures. Oriented plywood construction has a high wheel-carrying capacity. Hardwood plywood has excellent surface hardness, damage- and wear-resistance. Tropical plywood is made of mixed species of tropical timber. From the Asian region, it is now manufactured in African and South American countries. Tropical plywood is superior to softwood plywood due to its density, evenness of layers, high quality, it is sold at a premium in many markets if manufactured with high standards. Tropical plywood is used in the UK, United States, Korea and other countries worldwide, it is used for construction purposes in many regions due to its low cost. However, many countries’ forests have been over-harvested, including th
Lockheed P-38 Lightning
The Lockheed P-38 Lightning is a World War II–era American piston-engined fighter aircraft. Developed for the United States Army Air Corps, the P-38 had distinctive twin booms and a central nacelle containing the cockpit and armament. Allied propaganda claimed it had been nicknamed the fork-tailed devil by the Luftwaffe and "two planes, one pilot" by the Japanese; the P-38 was used for interception, dive bombing, level bombing, ground attack, night fighting, photo reconnaissance and visual pathfinding for bombers and evacuation missions, extensively as a long-range escort fighter when equipped with drop tanks under its wings. The P-38 was used most in the Pacific Theater of Operations and the China-Burma-India Theater of Operations as the aircraft of America's top aces, Richard Bong, Thomas McGuire and Charles H. MacDonald. In the South West Pacific theater, the P-38 was the primary long-range fighter of United States Army Air Forces until the appearance of large numbers of P-51D Mustangs toward the end of the war.
The P-38 was unusually quiet for a fighter, since the exhaust was muffled by the turbo-superchargers. It was forgiving and could be mishandled in many ways but the rate of roll in the early versions was too low for it to excel as a dogfighter; the P-38 was the only American fighter aircraft in large-scale production throughout American involvement in the war, from Pearl Harbor to Victory over Japan Day. At the end of the war, orders for 1,887 more were cancelled. Lockheed designed the P-38 in response to a February 1937 specification from the United States Army Air Corps. Circular Proposal X-608 was a set of aircraft performance goals authored by First Lieutenants Benjamin S. Kelsey and Gordon P. Saville for a twin-engine, high-altitude "interceptor" having "the tactical mission of interception and attack of hostile aircraft at high altitude." In 1977, Kelsey recalled he and Saville drew up the specification using the word interceptor as a way to bypass the inflexible Army Air Corps requirement for pursuit aircraft to carry no more than 500 lb of armament including ammunition, as well as the restriction of single-seat aircraft to one engine.
Kelsey was looking for a minimum of 1,000 lb of armament. Kelsey and Saville aimed to get a more capable fighter, better at dog-fighting and at high-altitude combat. Specifications called for a maximum airspeed of at least 360 mph at altitude, a climb to 20,000 ft within six minutes, the toughest set of specifications USAAC had presented; the unbuilt Vultee XP1015 was designed to the same requirement, but was not advanced enough to merit further investigation. A similar single-engine proposal was issued at the same time, Circular Proposal X-609, in response to which the Bell P-39 Airacobra was designed. Both proposals required liquid-cooled Allison V-1710 engines with turbo-superchargers and gave extra points for tricycle landing gear; the Lockheed design team, under the direction of Hall Hibbard and Clarence "Kelly" Johnson, considered a range of twin-engine configurations, including both engines in a central fuselage with push–pull propellers. The eventual configuration was rare in terms of contemporary fighter aircraft design, with only the preceding Fokker G.1, the contemporary Focke-Wulf Fw 189 Luftwaffe reconnaissance aircraft, the Northrop P-61 Black Widow night fighter having a similar planform.
The Lockheed team chose twin booms to accommodate the tail assembly and turbo-superchargers, with a central nacelle for the pilot and armament. The XP-38 gondola mockup was designed to mount two.50-caliber M2 Browning machine guns with 200 rounds per gun, two.30-caliber Brownings with 500 rpg, a T1 Army Ordnance 23 mm autocannon with a rotary magazine as a substitute for the non-existent 25 mm Hotchkiss aircraft autocannon specified by Kelsey and Saville. In the YP-38s, a 37 mm M9 autocannon with 15 rounds replaced the T1; the 15 rounds were in three five-round clips, an unsatisfactory arrangement according to Kelsey, the M9 did not perform reliably in flight. Further armament experiments from March to June 1941 resulted in the P-38E combat configuration of four M2 Browning machine guns, one Hispano 20 mm autocannon with 150 rounds. Clustering all the armament in the nose was unusual in U. S. aircraft, which used wing-mounted guns with trajectories set up to crisscross at one or more points in a convergence zone.
Nose-mounted guns did not suffer from having their useful ranges limited by pattern convergence, meaning that good pilots could shoot much farther. A Lightning could reliably hit targets at any range up to 1,000 yd, whereas the wing guns of other fighters were optimized for a specific range; the rate of fire was about 650 rounds per minute for the 20×110 mm cannon round at a muzzle velocity of about 2,850 ft/s, for the.50-caliber machine guns, about 850 rpm at 2,900 ft/s velocity. Combined rate of fire was over 4,000 rpm with every sixth projectile a 20 mm shell; the duration of sustained firing for the 20 mm cannon was 14 seconds while the.50-caliber machine guns worked for 35 seconds if each magazine was loaded with 500 rounds, or for 21 seconds if 300 rounds were loaded to save weight for long distance flying. The Lockheed design incorporated tricycle undercarriage and a bubble canopy, featured two 1,000 hp turbosupercharged 12-cylinder Allison V-1710 engines fitted with counter-rotating propellers to eliminate the effect of engine torque, with the turbochargers positioned behind the engines, the exhaust side of the units exposed along
Preston Thomas Tucker was an American automobile entrepreneur. He is most remembered for his Tucker 48 sedan nicknamed the "Tucker Torpedo", an automobile which introduced many features that have since become used in modern cars. Production of the Tucker'48 was shut down amidst scandal and controversial accusations of stock fraud on March 3, 1949; the 1988 movie Tucker: The Man and His Dream is based on Tucker's spirit and the saga surrounding the car's production. Preston Tucker was born on September 1903, on a peppermint farm near Capac, Michigan, he grew up outside Detroit in the suburb of Michigan. Tucker was raised by his mother, a teacher, after his father died of appendicitis when Preston was 2 years old. First learning to drive at age 11, Tucker was obsessed with automobiles from an early age. At age 16, Preston Tucker began purchasing late model automobiles, repairing/refurbishing them and selling the cars for a profit, he attended the Cass Technical High School in Detroit, but he quit school and landed a job as an office boy for the Cadillac Motor Company, where he used roller skates to make his rounds more efficiently.
In 1922, young Tucker joined the Lincoln Park, police department, his interest stirred by his desire to drive and ride the fast, high-performance police cars and motorcycles. His mother had him removed from the force, pointing out to department officials that at 19, he was below the department's minimum required age. Tucker and his new wife, Vera took over a 6-month lease on a gas station near Lincoln Park, running the station together. Vera would run the station during the day while Preston worked on the Ford Motor Company assembly line. After the lease ran out, Tucker quit Ford and returned to the police force again, but in his first winter back he was banned from driving police vehicles by the force after using a blowtorch to cut a hole in the dashboard of a cruiser to allow engine heat to warm the cabin. During the last couple of months at the gas station, Tucker began selling Studebaker cars on the side, he met an automobile salesman, Michael Dulian, who became sales manager for the Tucker Car Corporation.
Dulian hired Tucker as a car salesman at his Detroit dealership. Tucker did well, but the dealership was a long drive from his Lincoln Park home and so Tucker quit and returned to the police force for the last time. A few months Dulian, still impressed with Tucker's immediate success as a salesman, invited Tucker to move south with him to Memphis, Tennessee, to work as a sales manager. Dulian was transferred a couple of years but Tucker stayed in Memphis and was a salesman for Ivor Schmidt and John T. Fisher Motor Company, where he became general sales manager. While managing Chrysler sales in Memphis, Tucker made a connection with Pierce-Arrow. In 1933, Tucker moved to Buffalo, New York, became regional sales manager for Pierce-Arrow automobiles, but after only two years, he moved back to Detroit and worked as a Dodge salesman for Cass Motors. During the early 1930s, Tucker began an annual one-month trek to the Indianapolis Motor Speedway. Having a heavy interest in the race cars and their designers, Tucker met Harry Miller, maker of more Indianapolis 500-winning engines than any other during this period.
Tucker moved to Indianapolis to be closer to the racing car development scene and worked as the transportation manager for a beer distributor, overseeing the fleet of delivery trucks for the company. A better engineer than businessman, Miller declared bankruptcy in 1933 and was looking for new opportunities. Tucker persuaded Miller to join him in building race cars, they formed "Miller and Tucker, Inc." in 1935. The company's first job was building 10 souped-up Ford V-8 racers for Henry Ford; the time to develop and test the cars was insufficient and the steering boxes on all entrants overheated and locked up, causing them to drop out of the race. The design was perfected by privateers, with examples running at Indy through 1948. Miller and Tucker, Inc. continued race car development and various other ventures until Miller's death in 1943. Tucker was close friends with Miller and helped Miller's widow pay for her husband's funeral costs. While working with Miller, Tucker met the Chevrolet brothers and chief mechanic/engineer John Eddie Offutt, who would help Tucker develop and build the first prototype of the Tucker'48.
Tucker's outgoing personality and his involvement at Indianapolis made him well known in the automotive industry by 1939. In late 1937, while recovering in an Indianapolis hospital from an appendectomy, Tucker was reading the news about war looming on the horizon in Europe, he got the idea of developing a high-speed armored combat vehicle. In 1939, Tucker bought a house and property in Ypsilanti, he remodeled an old barn on his property and began and operated a machine shop called the Ypsilanti Machine and Tool Company, planning to use the facility to develop various automotive products. Opportunity arose for Tucker from the Dutch government, who wanted a combat vehicle suited to the muddy Dutch terrain. Continuing his working relationship with Harry Miller, Tucker began designing a narrow-wheelbase armored combat car powered by a Miller-modified Packard V-12 engine; the car was nicknamed the "Tucker Tiger". At least one prototype of the combat car was built. Production of the car was to be done at the Rahway, New Jersey, factory owned by the American Armament Corporation.
The Germans invaded the Netherlands in the spring of 1940 before Tucker could complete the deal, the Dutch government lost interest, so he completed the prototypes and opted to try to sell
The Boeing XP-7 was a prototype United States biplane fighter of the 1920s. The XP-7 started life as the last Boeing Model 15, serial 28-41, it was adapted to mount the 600 hp Curtiss V-1570 Conqueror engine. Labelled by Boeing as their Model 93, the XP-7's nose was shorter and deeper than that of the standard PW-9, the craft was 75 pounds lighter overall, it first flew in September 1928 and did well, with a 17 mph speed increase over the PW-9. However, despite a proposal to build an additional four P-7s, the design was at the limits of its capabilities and somewhat outdated by the time of its first flight. At the end of testing, the Conqueror engine was removed and the aircraft converted back into a PW-9D. United StatesUnited States Army Air Corps Data from General characteristics Crew: 1 Length: 24 ft 0 in Wingspan: 32 ft 0 in Height: 9 ft 0 in Wing area: 252 ft2 Empty weight: 2,358 lb Gross weight: 3,260 lb Powerplant: 1 × Curtiss V-1570-1, 600 hp Performance Maximum speed: 167.5 mph Cruise speed: 134 mph Range: 250 miles Service ceiling: 22,300 ft Rate of climb: 1408 ft/min Armament 1x.50in machine gun 1x.30in machine gun 125lb bombs Related lists List of military aircraft of the United States List of fighter aircraft BibliographyAngelucci, Enzo.
The American Fighter from 1917 to the present. New York: Orion Books. Lloyd S. Jones, U. S. Fighters pp. 32–33 ISBN 0-8168-9200-8
The Seversky P-35 is an American fighter aircraft built by the Seversky Aircraft Company in the late 1930s. A contemporary of the Hawker Hurricane and Messerschmitt Bf 109, the P-35 was the first single-seat fighter in United States Army Air Corps to feature all-metal construction, retractable landing gear, an enclosed cockpit; the origins of the P-35 can be traced back to the Seversky SEV-3 three-seat amphibian, designed by Alexander Kartveli, Seversky's chief designer and Seversky's first aircraft. The SEV-3 first flew in June 1933 and was developed into the Seversky BT-8 basic trainer, 30 of which were ordered by the United States Army Air Corps in 1935; this proved grossly underpowered and was replaced by the North American BT-9. The second prototype SEV-3 was completed as a two-seat fighter derivative, the SEV-2XP, it was powered by a 735 hp Wright R-1820 radial engine, had fixed landing gear in aerodynamic spats and was armed with one.50 in and one.30 in forward-firing machine guns plus an additional.30 in gun for rear defence.
When the USAAC announced a competition for a new single-seat fighter in 1935, Seversky sent the SEV-2XP, confident it would win despite being a two-seater. However, the aircraft was damaged on 18 June 1935 during its transit to the fly-offs at Wright Field. To compete with the Curtiss Model 75, a single-seat aircraft with retractable undercarriage, Seversky rebuilt the aircraft into the single seat SEV-1XP, replacing the SEV-2XP's fixed landing gear with a retractable undercarriage where the mainwheels retracted backwards into the wing, an 850 hp R-1820-G5 replacing the -F3 of the SEV-2XP; the SEV-1XP was delivered to Wright Field on 15 August for evaluation, successful, although the Cyclone failed to deliver its rated power and the SEV-1XP only reached 289 mph rather that the 300 mph predicted by Seversky. Protests from Curtiss led to the formal flyoff between the fighters to be delayed until April 1936; the delay was used by both Seversky and Curtiss to improve their aircraft, while allowing additional fighters from Vought and Consolidated with a single seat version of the PB-2.
The SEV-1XP was re-engined again, with a two-row Pratt & Whitney R-1830-9 "Twin Wasp" replacing the Cyclone and a modified vertical stabilizer fitted, becoming the SEV-7. The P&W failed to deliver its rated power as it put out only 738 hp, top speed was again well below 300 mph. Whilst more expensive than the Curtiss and Vought designs, the Seversky was a clear winner of the Air Corps' competition, with an order for 77 P-35 fighters and spare parts equivalent to eight airplanes being placed on 16 June 1936 at a cost of $1,636,250. Modifications from SEV-1XP to production P-35 standard included partial instead of complete mainwheel fairings and seven degrees of dihedral to the outer wing panels; the first production P-35 was delivered to the USAAC in May 1937, preceded by a company owned pre-production aircraft and demonstrator, the AP-1. Only 76 P-35s were built, delivery being completed in August 1938, with the 77th aircraft finished as the prototype XP-41; when it wanted further fighters in 1937, the Air Corps, who were unhappy with both the slow delivery of the P-35, sale of 2PA two-seat aircraft to the Japanese Navy, ordered 210 Curtiss P-36s.
Seversky continued to develop the design with the hope of selling more aircraft both to the Air Corps and to civil and export customers. It modified the prototype SEV-1XP as a single seat racer, the S-1 entering it into the 1937 Bendix Trophy, where it finished in fourth place; the competition was won by the S-2, a similar aircraft built for Frank Fuller of the Fuller Paint Company. S-2 won the Bendix Trophy in 1939 and placed second in 1938; the aircraft was used to portray the "Drake Bullet" in the 1938 film Test Pilot. Another civil aircraft was the DS, a single seater for James Doolittle, employed at the time by the Shell Oil Company, while the AP-7 was another racer, powered by a 1,200 hp R-1830 engine and used by Jacqueline Cochran to win the 1938 Bendix Trophy race and to set a women's air speed record. Seversky entered two aircraft based on the P-35 in a 1938 competition for a new fighter for the Air Corps. One was the XP-41 (which had the company designation AP-4D, a P-35 with a 1,200 hp R-1830-9 engine fitted with a two-stage supercharger and the AP-4, which had a turbo-supercharger mounted in the belly of a deeper fuselage.
The Air Corps preferred the AP-4D, ordered into production as the P-43 Lancer. Aiming to increase sales, Alexander P. de Seversky took a demonstrator on a tour of Europe in early 1939. As a result of this demonstration, Sweden ordered 15 EP-106 fighters on 29 June 1939, a development of the P-35 powered by a 1,050 hp R-1830-45, which improved performance by over 25 mph and armed with two 7.9 mm machine guns in the cowl and two 13.2 mm machine guns in the wings. A second order for 45 EP-106s was placed on 11 October 1939, with a third order for 60 aircraft, placed on 6 January 1940, although by this time Seversky had been thrown out of the company bearing his name by the board of directors, with the company renaming itself Republic Aviation; the Swedish Air Force designated them J 9. Seversky built a two-seater, the 2PA. Evolved in parallel with the P-35, the 2PA was a two-seat fighter and fighter-bomber with a fundamentally similar airframe and offered with either a similar undercarriage to that of the single-seater as the 2PA-L or with an amphibious float undercarriage as the 2PA-A.
Dubbed "Convoy Fighter" by the manufacturer, the 2PA was powered by a Wright R-1820-G2 or G3 Cyclone nine-cylinder
The Miles M.20 was a Second World War fighter developed by Miles Aircraft in 1940. It was designed as a simple and quick-to-build'emergency fighter' alternative to the Royal Air Force's Spitfires and Hurricanes should their production become disrupted by bombing expected in the anticipated German invasion of England. Due to dispersal of manufacturing, the Luftwaffe's bombing of the Spitfire and Hurricane factories did not affect production, the M.20 proved unnecessary and the design was not pursued. At the outbreak of the Second World War in September 1939, Miles Aircraft began work on a single-engined fighter to supplement the RAF's Spitfires and Hurricanes. A wooden mock-up of the design, the M20/1, was inspected by Sir Kingsley Wood, the Secretary of State for Air, but no orders followed. Following the outbreak of the Battle of Britain in July 1940, the Royal Air Force was faced with a potential shortage of fighters. To meet the Luftwaffe threat, the Air Ministry commissioned Miles to design a simple easy-to-build fighter to specification F.19/40.
This became the Miles M.20/2. Nine weeks and two days the first prototype flew. To reduce production time the M.20 employed all-wood construction and used many parts from the earlier Miles Master trainer, lacked hydraulics, had spatted fixed landing gear. The fixed undercarriage freed space and payload sufficient for twelve.303 Browning machine guns and 5000 rounds, 154 Imperial gallons of fuel. The M.20 was fitted with a bubble canopy for improved 360-degree vision. In line with a design philosophy emphasising simplicity, speed and re-using available components, the engine was a Rolls-Royce Merlin XX "power egg" identical to those used on Merlin-powered Avro Lancasters and Bristol Beaufighters; this conferred flight performance. The first prototype, with the B-class serial U-9 first flew on 15 September 1940, was tested at the A & AEE under the military serial number AX834 against Specification F.19/40. Armed with eight.303 Browning machine guns like the Hurricane, the M.20 prototype was faster than the Hurricane but slower than Spitfire types in production, but carried more ammunition and had greater range than either.
As the Luftwaffe had been defeated over Britain, the need for the M.20 had vanished and the design was abandoned without entering production. The first prototype was scrapped at Woodley. A second prototype, U-0228 was built to Specification N.1/41 for a Fleet Air Arm shipboard fighter, equipped with an arrestor hook and catapult launch points. It first flew on 8 April 1941; this variant could be launched by Catapult Aircraft Merchant ships which lacked flight decks so the aircraft were to be ditched after their mission, to facilitate this the undercarriage could be jettisoned. However, obsolete Hurricanes were modified to fill this role, which rendered a shipboard variant of the M.20 unnecessary. This prototype was scrapped. Data from The British Fighter since 1912General characteristics Crew: one pilot Length: 30 ft 8 in Wingspan: 34 ft 7 in Height: 12 ft 6 in Wing area: 234 ft² Empty weight: 5,908 lb Max. Takeoff weight: 8,000 lb Powerplant: 1 × Rolls-Royce Merlin XX V12 inline engine, 1,260 hp Performance Maximum speed: 333 mph Range: 920 mi Service ceiling: 32,800 ft Climb to 20,000 ft: 9 min 36 sArmament Guns: 8 ×.303 inch Browning machine guns Related development Miles MasterAircraft of comparable role and era Bell XP-77 Caudron C.714 Douglas XP-48 Hawker Hurricane Martin-Baker M.
B.2 Tucker XP-57 Related lists List of aircraft of World War II Miles M.20 shipboard fighter "Miles M.20" Miles M.20 aircraft profile "New Fighter in Nine Weeks" a 1944 Flight article