Abstract: A device for locking the ailerons and elevators of an aircraft controlled by a wheel-operated longitudinally shiftable and rotatable control column, and, at the same time preventing theft of the navigational instruments and radio equipment mounted on the instrument panel in the cockpit of the plane. The protective device takes the form of a cover plate mounted immediately adjacent the instrument panel by means of upper and lower clamping blocks secured about the control column in such a manner as to prevent unauthorized movements of the column and access to the instruments on the panel. The blocks have complementary semi-cylindrical grooves which clamp about the control column, and one block is fixed to the cover plate while the other has sliding, tongue and groove engagement to couple with said one block and clamp the control column against movement. The pair of blocks are held in clamped arrangement by a padlock whose shackle passes through aligned apertures in the blocks.