An actuating system for pivoting a wing tip section (13) about a fixed wing base section (11), and including a heating arrangement (33) positioned and adapted to be operable to heat at least one portion of an actuating arrangement (23) that pivots the wing tip section such that at least for ambient temperatures below a predetermined temperature the required work to be effected by the actuator (25) when moving the second coupling part (31) between the first position and the second position is lower than without heating the at least one portion.