This paper presents the control during take-off, transition and straight and level flight of a convertible aircraft based on Gain-Scheduling technique. The vehicle motion equations are deduced using Newton-Euler formulation. The lift, drag and pitch moment coefficients are modeled for angle of attack variations between one hundred eighty degrees and minus one hundred eighty degrees based on preliminary wing tunnel tests. The model of the aerodynamic effects caused by the wake rotors on the wing and horizontal stabilizer are taken into consideration. Numerical simulations are provided to verify the effectiveness of the proposed control strategy.