According to Benson of NASA (2010), the lift is generated due to the contact between the air and the flying solid object. Since the molecules of air is free to move, there is variation in both pressure and velocity along the flow of air. Making use of either the Bernoulli’s equation or Newton’s third law of motion, integration of either pressure or velocity variations would conclude an aerodynamic force.An aircraft cannot fly straight and level if it is in an out-of-trim position. If this happens, it would be difficult to control the attitude of the plane. The gauges and parts of the flight may not function properly. The pilot may also get disoriented and could end up in an accident.