h3 = −A (P cos γ − R sin γ) sin γ + K cos γ;

(8)

and the dynamical equation

dh3− h1Q + h2P = N,
dt

(9)

with K constant, and with preponderance downward

N = gMh cos zY sin γ = gMh sin γ sin θ cos φ,

(10)

reduces to

A d2φsin γ + Aμ2 sin γ sin2 θ sin φ cos φ
dt2