A wing-body model is tested in a wind tunnel with aflow of 100 m/s at standard sea-level conditions.

The wing area is 1.5 m^2 and the mean aerodynamicchord length is 0.45 m. Measurements of lift force, L, and momentabout the center of gravity, MCG are made using the wind tunnelforce balance.

The lead mass is removed and a horizontal tail withoutan elevator is added to the model. The distance from the airplanecenter of gravity to the aerodynamic center of the tail is 1.0m.

The area of the tail is 0.4 m2 and the tail-settingangle is -2.0°. The tail has a lift-curve slope of 0.12 per degree.Experimental measurements give the downwash in terms of angle ofattack, ε = α 0.42 , i.e. the downwash is zero for zero angle ofattack, 0
ε = 0

For the case where the angle of attack, α = 5.0°, andthe lift, L= 4134 N:

(i) Calculate MCG
(ii) Determine whether the model possesses longitudinal staticstability. Calculate Mo
(iii) Calculate the location of the neutral point and the staticmargin if h = 0.26.
(iv) An elevator is added to the horizontal tail with the property/ 0.04 L E T
∂ ∂ = C δ per degree.

In two ways calculate the elevator deflection anglerequired to trim the aircraft at an angle of attack of 8.0°. Answershould be the same.