7.9 Pipes and Hoses

Question 1

How are pipe sizes measured?

A. In inside diameter in inches.
B. In outside diameter in 1/16”.
C. In length and width.

Answer 1

B. In outside diameter in 1/16”.

Question 2

What should you do before bending a pipe?

A. Heat the pipe to high temperature.
B. Lubricate the pipe at the bend point lightly.
C. Bend the pipe without preparation.

Answer 2

B. Lubricate the pipe at the bend point lightly.

Question 3

What type of bend should be used for angles other than 90 degrees?

A. A straight bend.
B. An offset bend.
C. A sharp bend.

Answer 3

B. An offset bend.

Question 4

What is the recommended angle for a normal offset bend?

A. 30°.
B. 45°.
C. 60°.

Answer 4

B. 45°.

Question 5

What are the two types of flares?

A. Single flare and triple flare.
B. Single flare and double flare.
C. Double flare and quadruple flare.

Answer 5

B. Single flare and double flare.

Question 6

What is the angle used for both single and double flares?

A. 45 degrees.
B. 30 degrees.
C. 37 degrees.

Answer 6

C. 37 degrees.

Question 7

What types of flare are used for single flares?

A. Impact type and roll type.
B. Double flare and triple flare.
C. Crimp type and compression type.

Answer 7

A. Impact type and roll type.

Question 8

What types of fittings are used for double flares?

A. Swage Fitting/Harrison-type and Permaswage Fitting.
B. Crimp Fitting and Compression Fitting.
C. Impact Fitting and Roll Fitting.

Answer 8

A. Swage Fitting/Harrison-type and Permaswage Fitting.

Question 9

What is the preferred method of flaring?

A. Hammering type.
B. Roll type.
C. Crimp type.

Answer 9

B. Roll type.

Question 10

What is required when using the roll type flaring method?

A. Hammering.
B. No hammering required.
C. Heating the pipe.

Answer 10

B. No hammering required.

Question 11

AN. Feature. AC

37°. Angle. 35°

Yes. Recess. No

Coarser. Threads. Finer

Blue or Black. Colour. Grey or Yellow

Longer. Body Length. Shorter

Answer 11

Remember

Question 12

What type of piping can be double flared?

A. Soft aluminium piping with an outside diameter of 3/8 in or smaller.
B. Steel piping with an outside diameter of 1/2 in or smaller.
C. Copper piping with an outside diameter of 1/4 in or smaller.

Answer 12

A. Soft aluminium piping with an outside diameter of 3/8 in or smaller.

Question 13

How does a double flare compare to a single flare?

A. It is rougher and less concentric.
B. It is smoother and more concentric.
C. It is the same as a single flare.

Answer 13

B. It is smoother and more concentric.

Question 14

What is an advantage of double flaring?

A. It creates a weaker seal.
B. It provides a better seal.
C. It is less effective than a single flare.

Answer 14

B. It provides a better seal.

Question 15

What is an advantage of using a Permaswage fitting?

A. It is heavy and difficult to install.
B. It quickly seals in time-sensitive situations, is light, and provides a good seal.
C. It is not suitable for aircraft systems.

Answer 15

B. It quickly seals in time-sensitive situations, is light, and provides a good seal.

Question 16

What is a disadvantage of the Permaswage fitting?

A. It can be easily separated.
B. It cannot be separated, which can be problematic at disassembly.
C. It requires a special tool to assemble.

Answer 16

B. It cannot be separated, which can be problematic at disassembly.

Question 17

How can ridged piping lines carrying low-pressure fluids or air be connected to rubber hoses?

A. By welding the pipe ends together.
B. By belling the end of the pipe.
C. By using a compression fitting.

Answer 17

B. By belling the end of the pipe.

Question 18

How are aircraft pipes identified?

A. By using labels with the aircraft’s serial number.
B. By using tape with words, symbols, and colour coding.
C. By engraving the part number on the pipe.

Answer 18

B. By using tape with words, symbols, and colour coding.

Question 19

What pressure range is classified as high-pressure lines in aircraft?

A. Below 1500 psi (105 bar).
B. Over 1500 psi (105 bar).
C. Between 1000 psi (70 bar) and 1500 psi (105 bar).

Answer 19

B. Over 1500 psi (105 bar).

Question 20

Which materials are typically used for high-pressure lines?

A. Aluminium alloys.
B. Steel or titanium.
C. Copper.

Answer 20

B. Steel or titanium.

Question 21

What materials are medium and low-pressure lines preferably made of?

A. Steel or titanium to handle high pressure.
B. Aluminium alloys to save weight.
C. Copper and plastic for flexibility.

Answer 21

B. Aluminium alloys to save weight.

Question 22

What pressure range is classified as medium-pressure lines in aircraft systems?

A. Over 1500 psi (105 bar).
B. Below 1500 psi (105 bar).
C. Between 500 psi (35 bar) and 1000 psi (70 bar).

Answer 22

B. Below 1500 psi (105 bar).

Question 23

What type of lines are classified as low-pressure lines in aircraft systems?

A. Suction and return lines.
B. Lines with pressures over 1500 psi (105 bar).
C. Only fuel lines are low-pressure lines.

Answer 23

A. Suction and return lines.

Question 24

What material are hoses for engine and hydraulic systems typically made of in aircraft?

A. Rubber
B. Polytetrafluoroethylene (PTFE)
C. Stainless steel

Answer 24

B. Polytetrafluoroethylene (PTFE)

Question 25

What is the main advantage of Polytetrafluoroethylene (PTFE) hoses in aircraft? A. They are flexible and bend easily. B. They are chemically inert and unaffected by synthetic oils and fluids. C. They are only used in fuel systems.

Answer 25

B. They are chemically inert and unaffected by synthetic oils and fluids.

Question 26

What is the purpose of lay lines on aircraft hoses? A. To mark the manufacturing date. B. To ensure the line isn’t twisted. C. To indicate the maximum pressure rating.

Answer 26

B. To ensure the line isn’t twisted.

Question 27

What is the primary function of hoses in high-vibration areas of an aircraft? A. To connect stationary to moving parts (e.g., undercarriage retraction systems). B. To prevent fluid leakage in low-pressure systems. C. To cool down the hydraulic fluid.

Answer 27

A. To connect stationary to moving parts (e.g., undercarriage retraction systems).

Question 28

What does 4/90 mean on a hose

Answer 28

4 = Year Quarter 90 = year made

Question 29

How should a pipe be repaired when using the same material? A. The repair pipe should be of a different material to improve strength. B. The repair pipe must be made of the same material as the original pipe. C. The repair pipe should be made of a lightweight material.

Answer 29

B. The repair pipe must be made of the same material as the original pipe.

Question 30

What material can be used to repair CRES pipes if the same material is not available? A. Aluminium alloy pipes B. Titanium alloy pipes (except in the pylon) C. Copper pipes

Answer 30

B. Titanium alloy pipes (except in the pylon)

Question 31

Which materials can aluminium alloy pipes be repaired with? A. Only other aluminium alloy pipes B. CRES or Titanium alloy pipes C. Stainless steel pipes

Answer 31

B. CRES or Titanium alloy pipes

Question 32

What must be considered when using CRES pipes to replace steel pipes? A. The cost of the materials B. The weight penalty, as steel is heavy C. The maximum temperature the pipe can handle

Answer 32

B. The weight penalty, as steel is heavy

Question 33

What is the pressure rating for low-pressure hoses? A. Up to 3000 psi (20 685 kPa) B. Up to 600 psi (4137 kPa) C. 3000 psi or over (20 685 kPa or over)

Answer 33

B. Up to 600 psi (4137 kPa)

Question 34

What is the pressure rating for medium-pressure hoses? A. Up to 600 psi (4137 kPa) B. 3000 psi or over (20 685 kPa or over) C. Up to 3000 psi (20 685 kPa)

Answer 34

C. Up to 3000 psi (20 685 kPa)

Question 35

What is the pressure rating for high-pressure hoses? A. Up to 600 psi (4137 kPa) B. Up to 3000 psi (20 685 kPa) C. 3000 psi or over (20 685 kPa or over)

Answer 35

C. 3000 psi or over (20 685 kPa or over)

Question 36

How are pipes cleaned out internally? A. By immersing in water B. By using compressed air blown from both directions C. By using a cleaning solvent

Answer 36

B. By using compressed air blown from both directions

Question 37

What is the pressure used for proof-testing pipes? A. 1.5 times the working pressure B. 2 times the working pressure C. Equal to the working pressure

Answer 37

A. 1.5 times the working pressure

Question 38

What is an alternative method for replacing a short bend radius in hoses? A. Using a straight connector B. Using an elbow fitting C. Using a larger pipe diameter

Answer 38

B. Using an elbow fitting

Question 39

What is the primary function of protection sleeves for hoses? A. To protect hoses from corrosion and chemical exposure B. To protect hoses from abrasion and extreme heat C. To increase the pressure rating of hoses

Answer 39

B. To protect hoses from abrasion and extreme heat

Question 40

What materials are protection sleeves made of? A. Heat shrink, Nylon spiral wrap, Teflon B. Rubber, Plastic, Metal C. Cotton, Leather, PVC

Answer 40

A. Heat shrink, Nylon spiral wrap, Teflon

Question 41

Where should fluid lines never be routed? A. Through cargo compartments B. Through passenger compartments C. Through maintenance areas

Answer 41

B. Through passenger compartments

Question 42

How must fuel lines be bonded to the structure? A. Using zip ties B. Using integrally bonded line support clamps C. Using electrical tape

Answer 42

B. Using integrally bonded line support clamps

Question 43

What is the primary function of support clamps? A. Secure fluid lines, prevent chafing, and reduce stress B. Increase fluid flow C. Prevent heat transfer

Answer 43

A. Secure fluid lines, prevent chafing, and reduce stress

Question 44

Which type of clamp reduces vibration and prevents chafing? A. Plain clamps B. Reduced cushioned clamps C. Teflon cushioned clamps

Answer 44

B. Reduced cushioned clamps

Question 45

What is the purpose of plain clamps? A. To provide basic support for fluid lines B. To reduce vibration C. To prevent heat damage

Answer 45

A. To provide basic support for fluid lines

Question 46

Which type of clamp is used in fuel and hydraulic fluid areas due to its high resistance to deterioration? A. Plain clamps B. Reduced cushioned clamps C. Teflon cushioned clamps

Answer 46

C. Teflon cushioned clamps

Question 47

What is the primary use of bonded clamps? A. To secure fuel, oil, or hydraulic lines made from metal B. To increase pressure in fluid lines C. To regulate the flow of fuel

Answer 47

A. To secure fuel, oil, or hydraulic lines made from metal

Question 48

What is attached to a bonded clamp to ensure proper functionality? A. A hydraulic fluid regulator B. An electrical lead C. A pressure gauge

Answer 48

B. An electrical lead

Question 49

What is the purpose of the electrical lead on a bonded clamp? A. To increase flow rate B. To connect the line to the aircraft structure and ground/earth the line C. To monitor pressure

Answer 49

B. To connect the line to the aircraft structure and ground/earth the line

Question 50

What should you check on the hose identification tag? A. Part number, cure date (within limits), and assembly date (within limits) B. Hose material, weight, and pressure tolerance C. Manufacturer's name, assembly location, and length

Answer 50

A. Part number, cure date (within limits), and assembly date (within limits)

Question 51

What is the maximum depth of scratches or nicks in aluminum alloy piping that can be repaired by blending with hand tools? a) 5% of the wall thickness b) 10% of the wall thickness c) 15% of the wall thickness

Answer 51

b) 10% of the wall thickness

Question 52

Which of the following is acceptable for aluminum alloy piping? a) A crack or deformity in a flare b) A dent less than 20% of the pipe diameter, unless in the heel of a bend c) A dent greater than 20% of the pipe diameter

Answer 52

b) A dent less than 20% of the pipe diameter, unless in the heel of a bend

Question 53

Before cutting a pipe, how much longer should it be cut than needed? a) 5% longer b) 10% longer c) 20% longer

Answer 53

b) 10% longer

Question 54

What must pipes not have? a) Flattening, kinking, and wrinkling b) Only flattening c) Only kinking

Answer 54

a) Flattening, kinking, and wrinkling

Question 55

What is the flare angle for aviation? a) 45 degrees b) 30 degrees c) 37 degrees

Answer 55

c) 37 degrees

Question 56

What is the purpose of double flaring soft aluminum piping with an outside diameter of 3/8 in or smaller? a) To provide a stronger connection b) To reduce the risk of corrosion c) To increase flexibility

Answer 56

a) To provide a stronger connection

Question 57

What happens to a Harrison sleeve during installation? a) It is expanded outwards b) It is contracted inward c) It is cut to fit

Answer 57

a) It is expanded outwards

Question 58

What happens during the installation of a Permaswage fitting? a) It is expanded outwards b) It is squeezed on c) It is welded into place

Answer 58

b) It is squeezed on

Question 59

What document should be used for all plumbing repairs? a) Aircraft Maintenance Manual (AMM) b) Service Bulletin (SB) c) Regulatory Handbook

Answer 59

a) Aircraft Maintenance Manual (AMM)

Question 60

What do lay lines on pipes indicate? a) The manufacturer details b) The part number c) The pipe material

Answer 60

b) The part number

Question 61

What is important when installing hoses? a) They must be stretched tightly. b) They need to be slightly slack. c) They should be looped excessively.

Answer 61

b) They need to be slightly slack. NIT STRECHED

Question 62

What type of clamps are used on fuel lines? a) Spring clamps b) Bonded clamps c) Adjustable hose clamps

Answer 62

b) Bonded clamps

Question 63

What should be lubricated during plumbing repairs? a) The female fitting b) The male fitting c) Both fittings

Answer 63

b) The male fitting

Question 64

Where should the torque wrench and counter torque be applied when working with sleeve nuts and fittings? a) Torque wrench on the fitting, counter torque on the sleeve nut b) Torque wrench on the sleeve nut, counter torque on the fitting c) Both tools on the fitting

Answer 64

b) Torque wrench on the sleeve nut, counter torque on the fitting

Question 65

Why should there be at least one bend in each fitting? a) To prevent stretching under pressure b) To allow for flexibility and stress relief c) To simplify the installation process

Answer 65

b) To allow for flexibility and stress relief