The system (20) has a measurement device (40) measuring torque exerted on an upstream portion (11) of a drive train (10) when mounted. Another measurement device (50) measures speed of rotation of a gas generator (6) of a turboshaft engine (5) when mounted. A processor unit (25) is connected to the engine and the measurement devices when mounted. The processor unit automatically stops starting of the engine when the measured torque is lesser than a torque threshold and when the speed of rotation of the gas generator is greater than a speed threshold. Independent claims are also included for the following: (1) an aircraft (2) a method for starting a turboshaft engine of an aircraft.
