Equilibrium Incidence

The center of gravity is located at xcg/ lref = 0.21.

Find the static margin in % of lref.

Derive the formula for the equilibrium incidence a(tt). Check your result carefully as other results depend upon it.

14.5.3.2 Take-Off Conditions

The take-off lift coefficient for the complete configuration is CL, to = 2.0. Find the tail setting angle and the incidence at take-off.

The tail lift curve is given by

CLt = 2.49a + 2.61tt – 0.36

Find the tail lift coefficient at take-off.

Find the lift force (in N) on the tail at take-off. Take p = 1.225 kg/m3. Is it up or down?

14.5.3.3 Extra Credit

Sketch qualitatively the forces (main wing and tail lifts, weight) and forces locations at take-off with respect to the aerodynamic centers of the main wing (xacm/ lref = 0.21), of the tail (xact /lref = 0.85), of the complete configuration (xac/lref) and with respect to the center of gravity.

14.5 Problem 6