Editing Republic P-47 Thunderbolt (section)

==Development==
[[File:Republic P-43 Lancer.jpg|thumb|American prewar fighter Republic P-43 Lancer]]
[[File:XP-47 wind tunnel model.jpg|thumb|XP-47 model during wind tunnel testing]]
[[File:P-47 040315-F-9999G-029.jpg|thumb|P-47 firing its [[M2 Browning machine gun|M2 machine guns]] during night gunnery]]
[[File:Republic P-47D-22-RE Thunderbolt (sn 42-25969).jpg|right|thumb|P-47D-22-RE 42-25969 <br />8th AF / 361st FG / 376th FG <br /> flown by Capt. John D. Duncan.]]

The P-47 Thunderbolt was designed by [[Alexander Kartveli]], a man of [[Georgian people|Georgian]] descent. It was to replace the [[Seversky P-35]] developed earlier by a Russian immigrant named [[Alexander P. de Seversky]].{{#tag:ref|The P-47 can trace its lineage back to earlier Seversky designs: [[Seversky P-35|P-35]], [[Seversky XP-41|XP-41]], [[Republic P-43 Lancer|P-43]], and the unbuilt [[Republic P-43 Lancer|P-44]].<ref>Dorr and Donald 1990, pp. 84–85, 88.</ref>|group=Note}} Both had fled from their homeland, [[Tbilisi]], Georgia, to escape the [[Bolsheviks]].<ref name="Dwyer"/>{{#tag:ref|After a change in the board of directors, Alexander P. de Seversky was removed from the newly reorganized Republic Aviation company, with former Managing Director Wallace Kellett taking over as CEO.<ref>[http://www.acepilots.com/wwi/pio_seversky.html "Alexander de Seversky, Russian Ace of World War One, Aircraft Designer & Founder of Republic Aviation."] {{Webarchive|url=https://web.archive.org/web/20231202190908/https://acepilots.com/wwi/pio_seversky.html |date=2023-12-02 }} ''acepilots.com'', 2003. Retrieved: 16 May 2009.</ref>|group=Note}} 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 Lancer]]s were built, but Republic had been working on an improved [[Republic P-43 Lancer#P-44 Rocket|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]] [[Radiator (engine cooling)|liquid-cooled]] [[V12 engine|V-12]] engine and armed with two [[.50 BMG|.50&nbsp;in (12.7&nbsp;mm)]] [[M2 Browning machine gun]]s mounted in the nose and four [[7.62 mm caliber|.30 in (7.62 mm)]] [[M1919 Browning machine gun]]s mounted in the wings.<ref>{{Cite web|title=Republic XP-47B Thunderbolt|url=http://www.joebaugher.com/usaf_fighters/p47_1.html|access-date=2020-06-02|website=www.joebaugher.com|archive-date=2020-01-29|archive-url=https://web.archive.org/web/20200129163328/http://www.joebaugher.com/usaf_fighters/p47_1.html|url-status=live}}</ref> The [[United States Army Air Corps]] (USAAC) 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 then designed a much larger fighter, which was offered to the USAAC in June 1940, which 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 (except for the fabric-covered tail control surfaces) with [[elliptical wing]]s, with a straight leading edge that was slightly swept back. The P-47's airfoil section was developed by A. Kartveli and was designated as Republic S-3.<ref>{{Cite web |title=Design Analysis of the P-47 Thunderbolt |url=http://rwebs.net/avhistory/history/p-47.htm |access-date=2025-03-21 |website=rwebs.net}}</ref> The air-conditioned cockpit was roomy, and the pilot's seat was comfortable—"like a lounge chair", as one pilot later put it. The canopy doors hinged upward. Main and auxiliary [[self-sealing fuel tank]]s were placed under the cockpit, giving a total fuel capacity of {{cvt|305|USgal|impgal l|0}}.

[[File:P-47D-40 R 2800 side.jpg|thumb|A P-47 engine with the cowling removed: Uncompressed air enters through an intake under the engine and is carried to the turbosupercharger behind the pilot via the silver duct at the bottom. The olive-green pipe returns the compressed air to the engine.<ref name="Dwyer">Dwyer, Larry. [http://www.aviation-history.com/republic/p47.html "Republic P-47 Thunderbolt."] {{Webarchive|url=https://web.archive.org/web/20130429175214/http://aviation-history.com/republic/p47.html |date=2013-04-29 }} Aviation History Online Museum, 11 November 2010.</ref>]]

Power came from a [[Pratt & Whitney R-2800]] Double Wasp two-row, 18-cylinder radial engine producing {{convert|2000|hp|kW|abbr=on}} — the same engine that powered the prototype [[Vought F4U Corsair#Development|Vought XF4U-1]] fighter to just over {{convert|400|mph|km/h|abbr=on}} in October 1940—with the Double Wasp on the XP-47B turning a four-bladed [[Curtiss Aeroplane and Motor Company|Curtiss Electric]] [[constant-speed propeller]] of {{convert|146|in|m|abbr=on}} in diameter. The loss of the AP-4 prototype to an engine fire ended Kartveli's experiments with tight-fitting [[cowling]]s, 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, left and right oil coolers, and the [[Turbocharger|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 their forward ends and the [[turbine]] spun at 21,300&nbsp;rpm.<ref>[http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm "The Turbosupercharger and the Airplane Power Plant."] {{Webarchive|url=https://web.archive.org/web/20110109212349/http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm |date=2011-01-09 }} General Electric, January, 1943.</ref> The complicated turbosupercharger system with its ductwork gave the XP-47B a deep fuselage, and the wings had to be mounted in a relatively 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 wing-mounted machine guns could be fitted, each strut was fitted with a mechanism by which it telescoped out {{convert|9|in|cm|abbr=on}} while it extended.

The XP-47B was very heavy compared with contemporary single-engined fighters, with an empty weight of {{convert|9900|lb|kg|abbr=on}}, or 65% more than the YP-43. Kartveli said, "It will be a [[dinosaur]], but it will be a dinosaur with good proportions".<ref>[http://www.topfighters.com/fighterplanes/p47/lancer.html "P-47 Thunderbolt".] TopFighters.com. Retrieved: 12 July 2006.</ref> The armament was eight .50-caliber (12.7&nbsp;mm) "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]] around 100 rounds per second.<ref>Masefield, Peter. "First Analysis of the Thunderbolt." ''[[Flying (magazine)|Flying]]'', August 1943, p. 190.</ref>

The XP-47B first flew on 6 May 1941 with Lowry P. Brabham at the controls. Although minor problems arose, 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 {{convert|412|mph|km/h|abbr=on}} at {{convert|25800|ft|m|abbr=on}} altitude and had demonstrated a climb from sea level to {{convert|15000|ft|m|abbr=on}} in five minutes.<ref name="Green p.173">Green 1961, p. 173.</ref>

Though the XP-47B had its share of shakedown troubles, the [[1941 in aviation#June|newly reorganized]] [[United States Army Air Forces]] placed an order for 171 production aircraft, the first being delivered in December 1941.