Lift flap mechanism for adjusting a lift flap assigned to an airplane wing by means of a driving system, the lift flap mechanism comprising a main connection mechanism and a secondary connection mechanism in the form of a guide lever disposed in an articulated manner on the lift flap and the flap track, the main connection mechanism having a steering lever arrangement with at least one steering lever which has a first steering lever joint and a second steering lever joint, the at least one steering lever by way of a pendulum coupled to the first steering lever joint being connected with the flap track, and the second steering lever joint being guided such that, by means of a defined angular position of the at least one steering lever, the positions of the main connection joint and of the secondary connection joint are unambiguously determined.