The NVI F.K.33 was an airliner built in the Netherlands in 1925 for use by

KLM KLM Royal Dutch Airlines, legally ''Koninklijke Luchtvaart Maatschappij N.V.'' (literal translation: Royal Aviation Company Plc.), is the flag carrier airline of the Netherlands. KLM is headquartered in Amstelveen, with its hub at nearby Amste ...

for night flying.

Design and development

The F.K.33 was a largely conventional high-wing, strut-braced monoplane with seating for ten passengers in an enclosed cabin. A trimotor design, the placement of its engines was unusual. While two engines were mounted among the struts that braced the wings and the main units of the undercarriage, the third engine was mounted pusher-fashion on a set of struts above the wing. The engine installation was further unorthodox in that none of the three engines were enclosed in nacelles, remaining instead fully exposed.

Operational history

KLM successfully operated the type for two years on its

Amsterdam Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the capital and most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the urban ar ...

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Malmö Malmö (, ; da, Malmø ) is the largest city in the Swedish county (län) of Scania (Skåne). It is the third-largest city in Sweden, after Stockholm and Gothenburg, and the sixth-largest city in the Nordic region, with a municipal pop ...

route, but doing an increasing amount of business with Fokker, did not purchase further aircraft from NVI. The F.K.33 was eventually sold to German airline

Aero Aero is a Greek prefix relating to flight and air. In British English, it is used as an adjective related to flight (e.g., as a shortened substitute for aeroplane). Aero, Ærø, or Aeros may refer to: Aeronautics Airlines and companies * Aero ...

, but after two accidents within months of purchasing it, they returned it claiming poor workmanship. It was sold again in 1928, to Baumer-Aero, who replaced the Armstrong-Siddeley engines with

Junkers L5 The Junkers L 5 was a six-cylinder, water-cooled, inline engine for aircraft built in Germany during the 1920s. First run in 1925, it was a much enlarged development of the Junkers L2. Design and development The Junkers L5 was a development of J ...

s and the boarding lights with loudspeakers. In this configuration, it was flown as an advertising machine until 1931. The F.K.33 ended its days requisitioned by the

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

in 1939 as an instructional airframe.

Specifications

References

* * *
Koolhoven Aeroplanes Foundation

{{Koolhoven aircraft F.K.33 1920s Dutch airliners Three-engined push-pull aircraft High-wing aircraft Aircraft first flown in 1925