M7.9

Question 1

What pressure are high pressure lines?

Answer 1

Over 1500 PSI

Question 2

What pressure are medium pressure lines?

Answer 2

Under 1500 PSI

Question 3

What pressure are low pressure lines?

Answer 3

Suction and return

Question 4

What are medium and low pressure lines made out of?

Answer 4

Aluminium alloys for weight saving

Question 5

What are lines in the engine, landing gear, high chance of fire or stone damage made out of?

Answer 5

Steel or titanium

Question 6

What should be done when cleaning pipes and hoses?

Answer 6

blow compressed air in both ends

Question 7

How are pipes and hoses tested?

Answer 7

Tested at 1.5 of its normal working pressure with one end capped

Question 8

Why are support clamps used?

Answer 8

To secure to the aircraft structure or assemblies in the engine nacelle

Question 9

Why are rubber cushioned clamps used

Answer 9

To support pipes in high vibration areas

Question 10

What are cushioned clamps made from in high contamination areas?

Answer 10

Teflon

Question 11

What are bonded clamps used for?

Answer 11

To secure metal fuel, oil, hydraulic lines (it has electrical lead connecting to the structure)

Question 12

What is the flare angle for aircraft fittings?

Answer 12

37 degrees (45 for vehicle-types)

Question 13

What are the two way you can form a single flare?

Answer 13

Impact and roll (preferred)

Question 14

What is important to remember about AN fittings?

Answer 14

• 37 degrees
• has a recess
• coarser
• blue or black
• longer

Question 15

What is important to remember about AC fittings?

Answer 15

• 35 degrees
• no recess
• finer
• grey or yellow
• shorter

Question 16

When double flaring what is the largest diameter you can do?

Answer 16

3/8 or smaller

Question 17

Who normally produces hoses?

Answer 17

Manufacturer

Question 18

Where are hoses used?

Answer 18

High vibration areas and moving parts

Question 19

What are the three types of hoses?

Answer 19

• low pressure (up to 600 PSI)
• medium pressure (up to 3000 PSI)
• high pressure (3000+)

Question 20

What are the job of lay lines?

Answer 20

To see if it is twisted or not (yellow, red or white)

Question 21

What is the difference between hose length and assembly length?

Answer 21

Hose length is just the hose and assembly is including the fittings

Question 22

Why should there be some slack in a hose?

Answer 22

Because when it is pressurised it will reduce in length and increase in diameter

Question 23

What should you do if a part shows any sign of damage?

Answer 23

Reject it