Aircraft pneumatic system

An aircraft pneumatic system comprising:

• a line;
• a pneumatic actuator fluidly connected to the line downstream of the line, the pneumatic actuator operable to switch between an operative position and an inoperative position, the actuator being in the operative position upon receiving a line pressure within the line above a pressure threshold and being in the inoperative position upon the line pressure being at or below the pressure threshold;
• an indicator coupled to the pneumatic actuator, the indicator being indicative of whether the pneumatic actuator is in the operative position or in the inoperative position;
• a pneumatic source operatively connected to the pneumatic actuator via the line, the pneumatic source having a source outlet providing a fluid flow at a source pressure greater than the pressure threshold;
• a venturi having a venturi inlet fluidly connected to the source outlet and a venturi outlet fluidly connected to the line, the venturi sized relative to the pneumatic actuator and to the pneumatic source to pressurize the line such that the line pressure is:
• at the source pressure upon the pneumatic source providing the fluid flow at a mass flow rate of a nominal flow rate value below a graded flow rate value, and
• decreased from the source pressure to no more than the pressure threshold upon the mass flow rate having increased to at least the graded flow rate value.