Abstract: An actuator particularly adapted to control a plurality of bleed air valves of a gas turbine engine is disclosed. The actuator comprises n solenoid pilot valves where 2.sup.n is the number of actuation positions and 2.sup.n -1 is the number of bleed air valves to be actuated. The actuator receives as n bit digital signal corresponding to the number of bleed air valves to be actuated for a particular operating condition of the engine and the actuator converts this number into a correct mechanical position. The conversion is accomplished by a series of telescoping cylinder and piston assemblies each having an expandable chamber. Each chamber is independently contracted or expanded by an associated pilot valve controlling a pressure source in response to the presence or absence of a particular bit in the digital word. The size of the expandable chamber of each assembly is related to the others by ascending powerts of two and correspond to a bit position in the digital input signal.