A control system (10) for a gas turbine engine (1) having a gas generator (4) and a turbine (6) driven by the gas generator (4), is provided with: a control unit (12) to control a forward operating mode or a reverse operating mode of the gas turbine engine (1); and a supervising unit (14), operatively coupled to the control unit (12), to receive an input signal (PLA) indicative of a forward, or reverse, power request and to cause the control unit (12) to control the forward, or reverse, operating mode based on the input signal (PLA). The supervising unit (14) has an enabling stage (20) to enable a transition between the forward and reverse operating modes based on a check that a safety condition is satisfied.