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The Northrop N-3PB Nomad was a single-engined American floatplane of the 1940s. Northrop developed the N-3PB as an export model based on the earlier Northrop A-17 design.〔O'Leary 1981, p. 28.〕 A total of 24 were purchased by Norway, but were not delivered until after the Fall of Norway during the Second World War. Exiled Norwegian forces used them from 1941, operating from Iceland, for convoy escort, anti-submarine patrols, and training purposes from "Little Norway" in Canada.〔Parker, Dana T. ''Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II,'' pp. 100-2, Cypress, CA, 2013. ISBN 978-0-9897906-0-4.〕 Within two years of delivery, the design was effectively obsolete in its combat role, and the remaining N-3PBs were replaced by larger aircraft in 1943. ==Design and development== Following increased international tension surrounding the German annexation of the Sudetenland in 1938, the Norwegian parliament granted extraordinary appropriations to modernize the Norwegian Armed Forces. The Royal Norwegian Navy Air Service (RNNAS) and the Norwegian Army Air Service were prioritized for funds from the Norwegian Neutrality Fund. The RNNAS' share of the funds were designated to buy 12 Heinkel He 115 torpedo bombers and 24 reconnaissance aircraft, as well as several new naval air stations. The Dornier Do 22, Northrop 8-A, Northrop 2GP and Vultee V-11 GB were considered and proposals retrieved. The commission quickly decided the Vultee V-11 GB was the best aircraft to satisfy both air services' needs.〔Hafsten and Arheim 2003, p. 122.〕 On the part of the Royal Norwegian Air Service, the requirements were for a reconnaissance aircraft with a range of 1,500 km, a top speed of no less than 320 km/h and a payload of a 900 kg torpedo or the equivalent in bombs.〔 On 30 December 1939, Norway sent a purchasing commission to the United States, consisting of a Royal Norwegian Navy Air Service contingent headed by Cmdr. Kristian Østby, and a Norwegian Army Air Service contingent led by Birger F. Motzfeldt.〔〔March 1998, p. 187.〕 The goal of the commission was to inspect the Vultee V-11, which would serve as a new common reconnaissance bomber for the two air services.〔 Amongst the requirements the commission hoped to fill was replacing the Royal Norwegian Navy Air Service's M.F.11 biplane patrol aircraft.〔Ragnarsson 1981, p. 28.〕 Once in the US, the commission found that Vultee would not be able to deliver the V-11 within a reasonable amount of time so another aircraft had to be found.〔 Motzfeldt quickly found that the Douglas 8A-5N would satisfy the NOAAS' requirements. As the Douglas 8A-5N could not be fitted with floats, Østby continued to look for an aircraft suitable for the RNNAS.〔 After visits to many of the aviation companies in February 1940, Østby determined that only one manufacturer had both a design and available production capacity, Northrop Aircraft Incorporated. The commission ordered 24 floatplanes based on the Model 8-A, renamed the N-3PB, "off the drawing board" (literally, the aircraft being ordered prior to the type having flown) from Northrop on 8 March 1940, at a total cost of to meet this requirement. Half the amount was paid shortly before the German invasion of Norway on 9 April 1940.〔Parker, Dana T. ''Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II,'' pp. 93, 100-2, Cypress, CA, 2013. ISBN 978-0-9897906-0-4.〕〔Hafsten and Arheim 2003, pp. 120–122.〕 The Model 8-A, the export model of the Northrop Attack Bomber series was never intended to serve as the basis of a floatplane and had to be redesigned to meet the requirements of the Norwegian order. The new N-3PB was the first product of Northrop Aircraft, which had reformed in 1939, and was a low-winged cantilever monoplane fitted with twin floats. First intended for a lower powered engine, the N-3PB was ultimately powered by a Wright Cyclone radial engine, of the same type specified for the Douglas 8A-5N bombers and Curtiss Hawk 75A-8s ordered by Norway at the same time, simplifying the eventual maintenance and operation requirements for the entire Norwegian military aircraft fleets.〔Green 1962, pp. 185–186.〕 With the Norwegian operation requirements drawn up for a coastal reconnaissance floatplane, a series of modifications were requested to the original design. The changes included a redesign of the float structure to accommodate either a torpedo or bomb load carried under the center fuselage to supplement five underwing bomb racks. Additional armament changes led to a combination of six machine guns replacing the four machine gun (two fixed forward, two flexible rear-mounted 7.9 mm)/one cannon (forward facing, fixed 20 mm) arrangement that was in the initial design. Provision for a rear under-fuselage gun was also made.〔Stimpson, Thomas E. Jr. ("Speed Demons." ) ''Popular Mechanics'', 77(2), February 1942, p. 58.〕 Further equipment requirements including fitting a rear fuselage-mounted camera as well as changes to instrumentation and radio equipment.〔Ragnarsson 1981, pp. 28–29.〕 Before Northrop could complete any aircraft, Norway was invaded by Germany.〔Beauchamp 1976, p. 19.〕 The invasion and occupation of Norway necessitated that the armament of the N-3PB, originally to be installed in Norway, had to be changed. Initial specifications listed one Oerlikon 20 mm cannon in each wing, as well as two 7.9 mm Fabrique Nationale machine guns each in both fuselage and rear gunner stations.〔Ragnarsson 1981, p. 29.〕 Owing to the lack of availability of the originally specified armament, Norwegian-manufactured Colt heavy machine guns were substituted with four Colt MG53A .50 cal. machine guns in the wings and two .30 cal. Colt MG40s mounted in dorsal and ventral positions of the gunner's rear cockpit.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Northrop N-3PB」の詳細全文を読む スポンサード リンク
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