INFLUENCE OF FIN ON Clf

The sideslipping airplane gives rise to a side force on the vertical tail as explained in Sec. 8.1. When the aerodynamic center of the vertical surface is appreciably offset from the rolling axis (Fig. 8.11) then this force may produce a significant rolling moment. From (8.1,2 and 3) with bT = 0 this

P + o) — V2Sfzf

It

A 0, = «,(-j5 + <r)^

<•**>

THE DERIVATIVE C

“P

This is the yaw stiffness derivative, already treated in detail in Sec. 8.1.

THE DERIVATIVE CAr

This derivative gives the rudder hinge moment due to sideslip. It is analogous to the elevator hinge moment due to angle of attack. It is given

ЪУ д£м dotp

dp hr*f эр

where is the appropriate coefficient—see (6.5,1). By using (8.1,1) we get

(8.5,4)