Glider Equilibrium

Away from high lift, a linear model of the glider in terms of the angle of incidence a (deg) and tail setting angle tt (deg) is given by:

CL (a, tt) = 0.1a + 0.01tt + 0.7
CM,0(a, tt) = -0.02a — 0.01tt — 0.13

14.3.3.1 Definition

Give the definition of the aerodynamic center.

14.3.3.2 Aerodynamic Center

Find the location xac of the aerodynamic center, given that the reference length is lref = 1.5 m.

14.3.3.3 Moment at Aerodynamic Center

Derive CM, ac.

14.3.3.4 Moment at Center of Gravity

Derive CM, cg given a 4 % positive static margin.

Is the airplane statically stable? Explain.

14.3.3.5 Equilibrium

Derive the equilibrium incidence a(tt).

14.3 Problem 4