Influences the lift and AOA of the wing, the amount & direction of force on the tail, and the degree of deflection of the stabilizer needed to supply the proper tail force for equilibrium. This description refers to which parameter?

• A. Wing incidence
• B. CG position
• C. Tailplane setting
• D. Load factor

Answer: (B)

The idea being tested is how the center of gravity location drives trim and balance. Where the weight sits along the fuselage changes the pitching moment that must be countered to fly level. That moment is borne by the wing’s lift and by the tail’s reaction force, so moving the CG alters how much lift the wing must provide (and at what angle of attack) to hold the airplane in equilibrium, as well as how large and in what direction the tail force must be and how much stabilizer deflection is needed.

If the CG is forward, the nose tends to want to push down, so the tail must produce more downward force (and the elevator deflection must adjust accordingly) to balance, which also shifts the required wing attitude to keep level flight. If the CG shifts aft, the tendency changes toward nose-up, and the tail force required decreases or even reverses, changing stabilizer deflection as well. In short, the parameter that ties together wing lift/angle of attack, tail force, and stabilizer setting to achieve equilibrium is the center of gravity position.