9-12. 9-13. 9-14. 9-15. 9-16. The finger-lock actuators used on the landing gear have a down-limit switch mounted on and through the cylinder area for what purpose? 1. To indicate when the landing gear is down and locked 2. To allow pressure to be released during jacking operations 3. To allow the pilot to release the down locks during emergencies 4. To control hydraulic pressure to the emergency pneumatic extension line During normal extension of a landing gear finger-lock actuator, which of the following forces move(s) the piston over the fingers? In The airstream only Hydraulic pressure only Hydraulic pressure and spring tension only Hydraulic pressure, spring tension, and the airstream a power-operated flight control system, all the force necessary for deflecting the control surface is supplied by hydraulic pressure and wind force. True False A tandem-type,    control surface actuating cylinder uses a synchronizing rod for what purpose? 1. To direct pressure to each control surface 2. To isolate fluid pressure during an emergency 3. To equalize the flow of fluid into the actuator piston chambers 4. To allow the pilot to operate either flight control surface independently Which of the following procedures should you follow when cleaning the piston shaft of an actuating cylinder? Wipe it with engine oil Wipe it with aliphatic naphtha Wipe it with Freon, and then with grease Wipe it with dry-cleaning solvent, and then with hydraulic fluid 9-17. 9-18. 9-19. 9-20. 9-21. 9-22. In the maintenance of actuating cylinders, what is the most common trouble encountered? External leakage Internal leakage Mechanical damage Electrical damage Hydraulic pressure is converted into rotary mechanical motion by which of the following components? A hydraulic motor An actuating cylinder A power control cylinder A control surface actuator Hydraulic motors are commonly used to operate which of the following aircraft equipment? Rudders and stabilizers Radar and wing flaps Speed brakes and trim tabs Landing and arresting gear What type of a valve directs pressurized fluid to one working port of an actuating cylinder and, at the same time. returns fluid to the reservoir from the working port? An automatic check A sequence valve A selector valve A shuttle valve Which of the followinq other valve is NOT a type of selector valve? Slide Poppet Shuttle Solenoid-operated To relieve pressure created by thermal expansion of the fluid, a system that has a balanced poppet- type selector valve must also incorporate what other type of valve? A one-way check valve A thermal relief valve A sequence control valve A manually operated relief valve 44