The range of the movement for the configuration will range between -20 to +100 at 10 intervals. These angles must be relative to the fuselage datum.
The main function of the tail plane of an aircraft is to provide a sufficient amount of pitching moment while the aircraft is in flight and to control the aircraft in the longitudinal plane (Pankhurst & Holder, 1985). In order to achieve very efficient performance, the design of the airplane must take into consideration three important factors including; the geometrical relationship existing between the tail plane and the wing body of the aircraft, the performance of the tail plane and the structural components of the airplane (Irving, 2010).
This experiment is conducted due to the need to monitor and determine the performance of an aircraft and its variation at the different stages of its movement. The results obtained will help to determine the best configuration for airplanes in order to improve their performance.
The model of the airplane is mounted on an accurately and remotely operated 3 component mechanical balance. The incidence of the plane can be varied and the lift, drag and pitching moment be measured by means of weigh beams. The weigh beams usually have locks which should always be engaged when any adjustments are made to the model and also when the experiment is concluded. The balance is automatically locked when the stop button of the tunnel is pressed. Operation of the balance needs practice; the operator of the airplane must be accustomed to its natural frequencies. The forces that are acting on the plane model are lift, drag and the moment of the pitch. The airspeed can be deduced from the difference between the static pressures of the airstream at the point of entry and exit from the contractive of the tunnel. The pressure difference is usually equal to the dynamic head in the tunnel