7 - Electrical Wiring

Question 1

What is the mechanism for releasing a pin in a front release connector?

Answer 1

The pin is released from the front and extracted from the rear.

Question 2

What is the minimum bend radius for a wire clamped vertically at one end and horizontally at the other?

Answer 2

Three times the diameter of the wire.

Question 3

What can glycol deicer fluid in contact with a silver cable cause?

Answer 3

A fire.

Question 4

How is the pin released in a rear release connector?

Answer 4

The pin is released from the rear and extracted from the rear.

Question 5

What is the maximum operating temperature for a nickel plated copper or aluminium connector?

Answer 5

260°C.

Question 6

On what gauge of pin is a yellow plastic insert/extract tool used?

Answer 6

12–10.

Question 7

How can the insulation grip on a PIDG crimp tool be adjusted?

Answer 7

By adjusting the pins.

Question 8

On what gauge of pin is a red plastic insert/extract tool used?

Answer 8

22–18.

Question 9

Which type of cable should be used where temperatures exceed 200°C?

Answer 9

Nickel plated copper or aluminium.

Question 10

How long should a fireproof cable last in a fire?

Answer 10

15 minutes.

Question 11

On what gauge of pin is a blue plastic insert/extract tool used?

Answer 11

16–14.

Question 12

What is the minimum insulation resistance for wiring in undercarriage wheel‑wells?

Answer 12

2 megohms.

Question 13

What causes knuckling on older type electrical cables?

Answer 13

Excessive pull through forces.

Question 14

What test should be performed to find a high resistance or open circuit?

Answer 14

A continuity check.

Question 15

What is the maximum bonding resistance on an aircraft primary structure?

Answer 15

0.05 ohms.

Question 16

How should the bare ends of a cable be prepared before crimping?

Answer 16

They should be twisted lightly in the direction of the lay.

Question 17

What does the number of dots impressed on the insulation of pre‑insulated connectors indicate?

Answer 17

That the correct tool was used to effect the connection.

Question 18

How can the pressure of the insulation crimp jaws on a PIDG crimping tool be altered?

Answer 18

By changing the position of the pins.

Question 19

What does HRC mean in reference to fuses?

Answer 19

High rupture capacity.

Question 20

What color is the live wire when wiring an electrical component to a plug?

Answer 20

Brown.

Question 21

Why is a hole placed at the lowest point of electrical cable conduit?

Answer 21

To allow for drainage of moisture.

Question 22

What is the minimum distance between electrical cable splices?

Answer 22

500 mm.

Question 23

For how long is a fire‑resistant cable proof tested by exposure to a standard fire?

Answer 23

5 minutes.

Question 24

When fitting coaxial cable connectors, what is essential to ensure?

Answer 24

That no seals are damaged.

Question 25

When inserting pins into a front release connector, in which direction should the inserting tool’s gap face?

Answer 25

The outside of the connector.

Question 26

When is a crimp considered formed on a hydraulic crimping tool?

Answer 26

When the bypass valve opens and the ram returns to neutral.

Question 27

What type of binding tape is used for cables in temperatures above 260°C?

Answer 27

Teflon.

Question 28

What is the minimum bend radius for a loom adequately supported at a terminal block?

Answer 28

Three times the diameter.

Question 29

How are front release pins removed?

Answer 29

The tool is inserted from the front and the pin is removed from the rear.

Question 30

If a coaxial cable clamp is over‑tightened and compresses the dielectric, how does the capacitance change?

Answer 30

It increases.

Question 31

What is the minimum bend radius for a single coaxial cable?

Answer 31

Six times the diameter.

Question 32

What is wet arc tracking?

Answer 32

It is a fault caused by hot stamp printing.

Question 33

When using a heat shrink gun, to what temperature should it be set relative to the heat shrink temperature?

Answer 33

100° above the heat shrink temperature.

Question 34

In an electrical cable designation 1EF6B22NMS, what does the letter E represent?

Answer 34

Circuit function.

Question 35

How is cable impedance on a coaxial cable affected by its length?

Answer 35

It is not affected by length.

Question 36

What constitutes a secondary earth?

Answer 36

A secondary earth is typically 18 AWG.

Question 37

Under ATA 100, what does the symbol E′ on a wire indicate?

Answer 37

It indicates the system ID code.

Question 38

To prevent wet arc tracking, what should be controlled?

Answer 38

Hot stamp printing must be controlled.

Question 39

When splicing a cable with a soldered joint, when is the operation considered complete?

Answer 39

When the solder and insulation have formed.

Question 40

In manufacturing an electrical connector, what is done with the unused holes?

Answer 40

They are filled with connectors and blanked.

Question 41

In which application is coaxial cable preferred to airframe cable?

Answer 41

When the diameter of the cable is not important.

Question 42

How are forward release electrical connectors removed?

Answer 42

They are removed by pulling the wire backwards.

Question 43

How should wires be prepared when crimping?

Answer 43

They should be lightly twisted.

Question 44

Why are copper wires used in electrical systems?

Answer 44

Because they have a low resistance to current.

Question 45

When crimping wires, how should the wire be positioned relative to the crimp?

Answer 45

It should extend 0.8 mm beyond the crimp.

Question 46

In the cable designation 1EF6B22 NMSV, what does the letter B represent?

Answer 46

It represents the segment letter.

Question 47

What gauge of pin is a white/blue insertion‑extraction tool used on?

Answer 47

16.

Question 48

How does the insulation resistance of an electric motor compare to its supply leads?

Answer 48

It is smaller.

Question 49

According to ATA 100, what does the symbol code “X” on a wiring number denote?

Answer 49

AC power.

Question 50

When securing wire after it leaves an LRU, what is the minimum bend radius of the cable bundle?

Answer 50

Eight times the outside diameter of the cable or bundle.

Question 51

When terminating an aluminium cable, what preparation should be carried out before crimping?

Answer 51

Apply a mixture of 50% petroleum jelly and zinc oxide.

Question 52

Where should an in‑line splice be positioned?

Answer 52

On the outer surface of the loom for easy inspection.

Question 53

After crimping, what is the maximum conductor protrusion allowed from the terminal?

Answer 53

1/32 inch.

Question 54

When using a hand‑operated wire stripper, if the total stripping length exceeds a certain value, how many operations should be performed?

Answer 54

Two or more operations should be performed if the stripping length exceeds 0.75 inch.

Question 55

Through which location should a cable loom be protected by conduit?

Answer 55

Through the wheelwell door.

Question 56

What should the conduit size be relative to the maximum diameter of the electrical wires?

Answer 56

The conduit should be 25% larger than the maximum diameter of the wires.

Question 57

What gauge of contact is a blue metal extract tool used on?

Answer 57

16.

Question 58

What is the likely consequence of a silver‑coated conductor with damaged coating in a moist, unpressurized area?

Answer 58

It will likely cause Red Plague.