Embodiments pertain to a flap adjusting system including a regulating flap mounted on an airfoil using at least two bearing devices and movable relative to the airfoil, and an adjusting device. The adjusting device includes an actuator and adjusting kinematics with a drive rod that couples the actuator to the regulating flap using a first and a second joint, as well as a load sensor. The adjusting kinematics are configured such that, at a maximum adjustment travel of the regulating flap, the second joint between the drive rod and the regulating flap is adjusted by an angle less than 50% of the angle by which the first joint is adjusted. The load sensor is arranged in at least one adjusting device and in the second joint, which couples the drive rod to the regulating flap. The load sensor is configured to measure the forces in this load path.