(1) Relief valves are used in pneumatic system as damage-preventing units. (2) Check valves are used in both hydraulic and pneumatic systems. Regarding the above statements

How many of these seals are used with petroleum base hydraulic fluids?

Although dents in the heel of a bend are not permissible, they are acceptable in the remainder of a hydraulic tube providing they are less than what percent of the tube damenter

Which is a characteristic of synthetic base hydraulic fluid?

To prevent external and internal leakage in aircraft hydraulic units, the most commonly used type of seal is the

Two types of hydraulic fluids currently being used in civil aircraft are

Where can information be obtained about the compatibility of fire resistant hydraulic fluid with aircraft materials?

The purpose of restrictors in the hydraulic system is to

Hydraulic fluid reservoirs are sometimes designed with a standpipe in one of the outlet ports in order to assure emergency supply of fluid. The outlet port with the standpipe in it furnishes fluid to the

The primary purpose of a hydraulic actuating unit is to transform

What is one advantage of piston type hydraulic motors over electric motors?

What is the purpose of using backup rings with O-rings in hydraulic systems above 1500 psi?

The air that is expended and no longer needed when an actuating unit is operated in a pneumatic system is

Phosphate ester base hydraulic fluid is very susceptible to contamination from

Hydraulic fluid filtering elements constructed of pours papers are normally

A common cause of slow actuation of hydraulic components is

(1) materials which are skydrol compatible or resistant include most common aircraft metals and polyurethane and epoxy paints (2) skydrol hydraulic fluid is compatible with nylon and natural fibers regarding the above statements

Which valve installed in a hydraulic system will have the highest pressure setting?

Which must be done before adjusting the relief valve of a main hydraulic system incorporating a pressure regulator?

Chatter in a hydraulic system is cause by

A flexible sealing element subject to motion is a

Heat exchanger cooling units are required in some aircraft hydraulic system because of

Components containing phosphate ester-based hydraulic fluid may be cleaned with

One of the distinguishing characteristics of an open-center selector valve use in a hydraulic system is that

A pilot reports that when the hydraulic pump is running, the pressure is normal. However when pump is stopped no hydraulic pressure is available. This is an indication of a

A hydraulic system operational check during ground runup the wing flaps cannot be allowed using the main hydraulic system, but can be lowered by using the emergency likely cause

Select the valve used in a hydraulic system that directs pressurized fluid to one end of an actuating cylinder and simultaneously directs return fluid to the reservoir from the other end.

Refer to Airframe (Figure No. 12) Which illustration (s) show (s) the correct spiral for teflon backup rings?

Refer to Airframe (Figure No. 11) Which fitting is an Airforce Navy (AN) flared tube fitting?

The component in the hydraulic system that is used to direct the flow of fluid is the

Chattering of the hydraulic pump during operation is an indication

In a gear-type hydraulic pump, a mechanical safety device incorporated to protect the pump fron overload is the

A loud hammering noise in a hydraulic system having an accumulator usually indicates

Some hydraulic system incorporate a device which is designed to remain open to allow a normal fluid flow in the line, but closed if the fluid flow increases above an established rate. This device is generally referred to as

Which seal/material is ised with phosphate ester base hydraulic fluid?

Generally the first step in removing an accumulator from an aircraft is to

When hydraulic system pressure control and relief units fail to function properly. How are most systems protected against over pressure

Hydraulic accumulator is charge with an air preload of 1000 PSI. when a hydraulic system pressure of 3000 PSI is developed, the pressure on the air side of the accumulator will be

The internal resistance of fluid which tend to prevent it from flowing is called

After installation of a rebuilt hydraulic hand pump. It is found that the handle cannot be moved in the pumping directions (pressure stroke). The most likely cause is an incorrectly installed

A unit which transforms hydraulic pressure which linear motions is called

Unloading valves are used with many engine-driven hydraulic pumps to

If a rigid tube is too short for the flare to reach its seat before tightening, pulling it into place by tightening

A hydraulic pump is a constant -displacement type if it

Teflon hose that has developed a permanent set from being exposed to high pressure or temperature should

Seals used with a mineral base gudraulic fluid are identified by which color code?

The main system pressure relief valve in a simple hydraulic system equipped with a power control valve should be adjusted.

If hydraulic fluid is released when the air valve core of the accumulator is deressed, it is evidence

Most variable displacement aircraft hydraulic pumps in use.

One of the main advance of skydrol is its

What safety device is usually located between the driving unit and hydraulic pump drive shaft?

Which allows free fluid flow in one direction and no fluid flow in the other direction?

If an aircraft's constant pressure hydraulic system and no more frequently than detected the most probable cause is

What is the main purpose of a pressurized reservoir in a hydraulic system?

Which seal/material is used with phosphate ester base hydraulic fluids?

Excluding lines , which components are required to make up a simple hydraulic system?

How can the proper hydraulic fluid to be used in an airplane be determined?

Using a hand pump pressure of 100 psi has been built up in a hydraulic system, the hand pump piston is 1 inch in diameter. A 1/2 inch line connects the hand pump to an actuating cylinder 2 inches in diameter. What is the pressure in the line between the hand pump and the actuator?

A worn hydraulic pump shaft seal can normally be detected by

An emergency supply of fluid is often retained in the main hydraulic system reservoir by the use of a standpipe. The supply line is connected to the

What type of packings should be used in hydraulic components to be installed in a system containing skydrol?

What types of selector valve is one of the most commonly used in hydraulic system to providing for simultaneous flow of fluid into and out of a connected actuating unit?

Which of the following is adversely affected by atmospheric humidity if left unprotected?

In a hydraulic system that has a reservoir pressurized with turbine-engine compressor bleed air, which unit reduces the air pressure between the engine and reservoir.

If it is necessary to adjust several pressure regulating valves in a hydraulic system, what particular sequence, if any, should be followed?

If a hydraulic brake system use neoprene rubber packing materials, the correct hydra fluid to service the system is

A hydraulic motors convert fluid pressure to

What functions does the absolute pressure regulator perform in the pneumatic power system?

Characteristics of MIL-H-8466 (skydrol 500 A & B) hydraulic fluids are

Petroleum base hydraulic fluid is which color?

Pressure is a term used to indicate the force per unit area. Pressure is usually expressed in

A crossflow valve which is designed to bypass fluid from one side of an actuating cylinder to the side, under certain conditions, may be found in some aircraft installed in the

How is the air in a hydraulic accumulator prevented fron entering the fluid system?

Hydraulic pump system accumulating serve which of the following instructions?

Quick-disconnect couplings in hydraulic system provide a means of

An aircraft pneumatic system which incorporates an engine-driven multistage reciprocating compressor, also requires

A characteristic of MIL-H-7644 hydraulic fluid are

Which allows free fluid flow in one direction and no fluid flow in the other direction?

Which valve installed in a hydraulic system will have the highest pressure setting?

Before removing the filler cap of a pressurized hydraulic reservoir, in order to service the system, you must

Which seals are with petroleum base hydraulic fluids?

Pneumatic systems utilize

Characteristics of MIL-H-5606