A method of determining a duration of a movement of a starter air valve of a turbine engine, the valve for regulating the passage of a flow of pressurized air from upstream to the downstream of pipework, where the downstream side is connected to a pneumatic starter of the turbine engine, the method including determining an instant of initiation and an instant of completion of a movement of the valve during a movement phase of the valve, determining the duration of the movement of the valve, by subtracting the instant of initiation from the instant of completion, calculating a difference between the determined duration of the movement and a theoretical value of the duration.