Wing Configuration - Number and Position of Main-planes

Number and Position of Main-planes

Fixed-wing aircraft can have different numbers of wings:

• Monoplane - one wing plane. Most aeroplanes have been monoplanes since the 1930s. The wing may be mounted at various positions relative to the fuselage:
  • Low wing - mounted near or below the bottom of the fuselage.
  • Mid wing - mounted approximately half way up the fuselage.
  • Shoulder wing - mounted on the upper part or "shoulder" of the fuselage, slightly below the top of the fuselage. Being sited only slightly lower than a high wing, a shoulder wing is sometimes considered a sub-type of a high wing.
  • High wing - mounted on the upper fuselage. When contrasted to the shoulder wing, applies to a wing mounted on a projection (such as the cabin roof) above the top of the main fuselage.
  • Parasol wing - raised clear above the top of the fuselage, typically by cabane struts, pylon(s) or pedestal(s).

A fixed-wing aircraft may have more than one wing plane, stacked one above another:

• Biplane - two wing planes of similar size, stacked one above the other. The most common configuration until the 1930s, when the monoplane took over. The Wright Flyer I was a biplane.
  • Unequal-span biplane - a biplane in which one wing (usually the lower) is shorter than the other, as on the Curtiss JN-4 Jenny of the First World War.
  • Sesquiplane - literally "one-and-a-half planes" is a type of biplane in which the lower wing is significantly smaller than the upper wing, either in span or chord or both. The Nieuport 17 of WWI was notably successful.
  • Inverted sesquiplane - has a significantly smaller upper wing. The Fiat CR.1 was in production for many years.

• Triplane - three planes stacked one above another. Triplanes such as the Fokker Dr.I enjoyed a brief period of popularity during the First World War due to their manoeuvrability, but were soon replaced by improved biplanes.

• Quadruplane - four planes stacked one above another. A small number of the Armstrong Whitworth F.K.10 were built in the First World War but never saw service.

• Multiplane - many planes, sometimes used to mean more than one or more than some arbitrary number. The term is occasionally applied to arrangements stacked in tandem as well as vertically. The 1907 Multiplane of Horatio Frederick Phillips flew successfully with 200 wing foils, while the nine-wing Caproni Ca.60 flying boat was airborne briefly before crashing.

A staggered design has the upper wing slightly forward of the lower. Long thought to reduce the interference caused by the low pressure air over the lower wing mixing with the high pressure air under the upper wing however the improvement is minimal and its primary benefit is to improve access to the fuselage. It is common on many successful biplanes and triplanes. Backwards stagger is also seen in a few examples such as the Beechcraft Staggerwing.

A tandem wing design has two wings, one behind the other - see Tailplanes and foreplanes below. Some early types had tandem stacks of multiple planes - see the article on multiplanes.