U.S. Patent Specifications

In an aeroplane, a plurality of flaps to be moved through a range of positions, a reversible flap actuating motor for each flap, a pilot moved control member, a follow‐up member moved by one of said flaps only, a pair of direction switches co‐operating with said members and with said actuating motors to actuate said motors by movement of said control member to move said flaps to positions directly related to the amount of movement of said control member, a limit switch positioned at each flap to be opened only when its respective flap is in a predetermined position, said predetermined position being at one extremity of said range of positions just short of the position normally called for by one of said direction switches at one end position of said control member, said limit switches being connected in parallel with each other and in series with said one direction switch to open said series circuit while said one direction switch is still closed, whereby all of said flaps will reach said predetermined position before said flap actuating motors are de‐energized, a pointer attached to said follow‐up member, and calibrated scale means associated with said control member and said pointer to indicate the actual position of the flap connected to said follow‐up member at all times.