Page:Aerial Flight - Volume 2 - Aerodonetics - Frederick Lanchester - 1908.djvu/125

Rh and, carrying the correction through, we reach finally,

$\Phi = \frac{4 l H_n^2 \tan \gamma}{\mbox{I} \left(\frac{1}{K} + \frac{1}{c C \rho \epsilon \alpha \beta} \right)} > 1$

which is the complete equation of stability. It will be noted that the correction has been based on the supposition that the tail is long, that is to say that the tail plane is well out of the immediate influence of the aerofoil, and is only affected by the residual peripteral motion.