The Farman F.1020 was an
experimental aircraft built in
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
in 1933 to investigate the behaviour of a semi-circular wing fitted with unconventional controls. It had a short career and only one was constructed.
Design
The Farman F.1020 was built to test a novel wing design, the study of which had begun in 1926. Its plan was essentially semicircular, with the straight edge leading. The chord was thus broad and the
aspect ratio very low. Such a wing has high
induced drag
In aerodynamics, lift-induced drag, induced drag, vortex drag, or sometimes drag due to lift, is an aerodynamic drag force that occurs whenever a moving object redirects the airflow coming at it. This drag force occurs in airplanes due to wings or ...
but was thought to offer good transverse stability and low speed behaviour. It has such features in common with some
tailless and
delta designs.
The wing of the F.1020 had a near circular trailing edge which squared off into straight tips. The leading edge was a little further forward than the diameter of the idealised semicircle would have been and was slightly swept; it was also extended beyond the rest of the wing, carrying conventional
ailerons
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...
. The maximum chord, at the wing root, was 5 m, compared with a span of 7.2 m; the aspect ratio was 2.1. The trailing edge carried deep chord control surfaces, two per side: the outer pair were used differentially like ailerons and the inner ones as flaps.
This wing was mounted on the fuselage of a
Farman F.402, retaining the
empennage
The empennage ( or ), also known as the tail or tail assembly, is a structure at the rear of an aircraft that provides stability during flight, in a way similar to the feathers on an arrow.Crane, Dale: ''Dictionary of Aeronautical Terms, third e ...
, undercarriage and the 110 hp (82 kW)
Lorraine
Lorraine , also , , ; Lorrain: ''Louréne''; Lorraine Franconian: ''Lottringe''; german: Lothringen ; lb, Loutrengen; nl, Lotharingen is a cultural and historical region in Northeastern France, now located in the administrative region of Gra ...
5-cylinder radial engine. As on the F.402, the wing was placed on top of the cabin with two square windows in the roof for upward visibility. The control system enabled the pilot to switch between conventional (aileron, elevator, rudder) control and that provided by the trailing edge surfaces.
Operational history
The first flight of the F.1020, nicknamed the ''Pelle-bêche'' (en:Digging-shovel or Spade) and registered as ''F-AMOG'', was in December 1933, piloted by Lucien Coupet. Thereafter it was only flown by Henry Farman who found it almost impossible to spin, but without any other particular merits. A design study was made for a variant with a shorter, 4 m, chord, designated F.1021, but this was not built.
Specifications
References
Bibliography
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External links
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{{Farman aircraft
1930s French experimental aircraft
F.1020