Specifications Assume a Biplane with the following spec:-

Wing Span 100" Plain rectangular wing Area 1200 sq inches per wing.

Chord 12"

Wing Gap between Upper & Lower Wings 12"

Stagger 3"Note Top wing is Forward of the Lower Wing, this is Positive Stagger in Figure D-2

First determine the value of Kusing Figure D-2

The Stagger Angle is Tan Ø = Stagger/Gap = 3/12(0.25) = +14 degs Gap/Chord = 12/12 = 1

Using Figure D-2 (shown in red) K = 1.25

Inserting 1.25 (K) into the equation g = 6.35

From this we have established that the plane of the MAC lies 6.35" above the Chord line of the Lower Wing. The location of the Center of Gravity on the MAC line can now be established using other methods detailed on this web article.

Text © Colin Usher 2011 Illustrations © Colin Usher 2011

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