6:10 Control Cables

Question 1

What is the main advantage of control cables over other mechanical means such as actuators or shafts and chains

Answer 1

Weight saving

Question 2

Is handling, checking and adjusting control cables easy or hard

Answer 2

Relatively easy

Question 3

In aircraft construction what is the minimum tensile strength for individual cables

Answer 3

1200nm squared at a breaking elongation of 2-7%

Question 4

How are cables made up (3 step)

Answer 4

Wires-strands-cables

Question 5

How are the wires and strands twisted

Answer 5

The the wires are twisted one way and the strands another

Question 6

What are non flexible cables normally used for

Answer 6

Purposes such as drag or anti drag wires or bracing

Question 7

When would extra flexible cables be used

Answer 7

Over primary flight controls or when the operation over w pulley is frequent

Question 8

How would you check the tension of large aircraft cables

Answer 8

By using a tensiometer

Question 9

How are end connections attached to cables

Answer 9

By swaging

Question 10

What are the different cable terminal types

Answer 10

• Ball (single or double shank)
• Stud end
• Fork end
• Eye end

Question 11

What are fairleads

Answer 11

Fairleads are used to guide control cables to prevent contact with the aircraft structure

Question 12

What are pressure seals

Answer 12

Pressure seals are like fairleads but are used when a cable passes through a pressure bulkhead

Question 13

What is the purpose of pulleys

Answer 13

Pulleys are used in cable runs to effect a change in direction

Question 14

What is the purpose of a turnbuckle

Answer 14

Turnbuckles are a mechanical screw device. They are used in cable control runs to make minor adjustments to cable length or cable tension

Question 15

What type of threads do turnbuckles have

Answer 15

One end has a right hand thread and the other has a left hand thread

Question 16

What ways can turnbuckles be locked

Answer 16

Normally a clip type lock is used

Question 17

What is a cable tension regulator

Answer 17

A mechanical device used in aircraft to maintain cable tension even through changes in temperature

Question 18

What must be done to cable tension regulators when they need to be disconnected from cable runs

Answer 18

They must be locked or snubbed (can be very dangerous if they are not

Question 19

What is the major advantage of cable and conduit over other methods

Answer 19

Relatively light and installation is simple

Question 20

What are two examples of cable and conduit control run

Answer 20

Teleflex and Bowden

Question 21

What type of transmissions can teleflex cables operate

Answer 21

Push and pull

Question 22

When are sliding end fittings used

Answer 22

Where it is not necessary to convert a pull-push movement in to a rotary movement

Question 23

What is used to take up angular movement in control runs

Answer 23

Swivel joints

Question 24

What is the rotary travel limited to in a single entry unit and what what angle of engagement must be maintained between the gear wheel and the teeth of the cable

Answer 24

Limited to 270° and a minimum of 40° of engagement

Question 25

Why would a double entry unit be required over a single entry unit

Answer 25

When a greater amount of travel is required

Question 26

When would swivel joints be installed

Answer 26

Where rotary movement of the control lever at the receiving end does not exceed 90°

Question 27

What is the purpose of quick break units

Answer 27

They are installed in control runs to facilitate the removal of a component with out disturbing the run

Question 28

What must rigid conduit be

Answer 28

Clean, free from dents and deformation and reasonably straight

Question 29

Can damage to rigid conduit be repaired

Answer 29

It can be repaired by inserting a new length of conduit and by using a connector to connect both ends together

Question 30

When tightening a nipple type connector why should two spanner’s be used

Answer 30

To prevent damaging the conduit

Question 31

How do Bowden cable runs operate

Answer 31

They operate as pull only and the return is acted by a spring

Question 32

What is the purpose of a junction box

Answer 32

A junction box is used to connect a single cable to two others where two components are to be operated by a single control

Question 33

What is the minimum bend radius for Bowden cable conduit

Answer 33

12x diameter of the conduit

Question 34

If a Bowden conduit is damaged must it be renewed or can it be repaired

Answer 34

It must be replaced

Question 35

For Bowden controls longer than 2ft, how often should the run be supported

Answer 35

Every 12 inches

Question 36

What must a Bowden cable be lubricated with

Answer 36

Graphited synthetic grease applied at room temperature (60-70°f)