Junkers F13

F.13
Junkers F.13 in the Deutsches Museum
Role	small passenger transport
Manufacturer	Junkers
Designer	Otto Reuter
First flight	June 25, 1919
Introduction	1920
Retired	late 1930s
Primary users	Junkers Luftverkehr DLH, LAB, LOT, ÖLAG
Produced	1919–1932
Number built	322

The Junkers F.13 (also known as the F 13) was the world's first all-metal transport aircraft, developed in Germany at the end of World War I. It was an advanced cantilever-wing monoplane, with enclosed accommodation for four passengers. Over 300 were sold. It was in production for thirteen years and in commercial service for almost twenty.

The F.13 was a very advanced aircraft when built, an aerodynamically clean all-metal low-wing cantilever (without external bracing) monoplane. Even later in the 1920s, it and other Junkers types were unusual as unbraced monoplanes in a biplane age, with only Fokker's designs of comparable modernity. It was the world's first all-metal passenger aircraft and Junkers' first commercial aircraft.

The designation letter F stood for Flugzeug, aircraft; it was the first Junkers aeroplane to use this system. Earlier Junkers notation labelled it J 13. Russian-built aircraft used the designation Ju 13.

Like all Junkers duralumin-structured designs, from the 1918 J 7 to the 1932 Ju 46, (some 35 models), it used an aluminium alloy (duralumin) structure entirely covered with Junkers' characteristic corrugated and stressed duralumin skin. Internally, the wing was built up on nine circular cross-section duralumin spars with transverse bracing. All control surfaces were horn balanced.

Behind the single engine was a semi-enclosed cockpit for the crew, roofed but without side glazing. There was an enclosed and heated cabin for four passengers with windows and doors in the fuselage sides. Passenger seats were fitted with seat belts, unusual for the time. The F.13 used a fixed conventional split landing gear with a rear skid, though some variants landed on floats or on skis.

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