6.10- Control Cables

Question 1

What is the standard minimum tensile strength of aircraft control cables?

Answer 1

1200N/mm² at a breaking elongation of 2-7%.

Question 2

What are steel wires twisted into?

Answer 2

Strands which are then twisted into cables.

Question 3

Non flexible cable is normally what strand x wires?

Answer 3

1 x 19

Question 4

What is 1 x 9 cable generally used for?

Answer 4

Bracing, drag and anti-drag wires.

Question 5

What is 7x7 cable used for?

Answer 5

Trim tab controls, engine controls and indicator controls.

Question 6

Where is 7x19 cable used?

Answer 6

Primary control systems and pulley systems.

Question 7

How are metal cable terminals fitted to cables?

Answer 7

Swaged by plastic deformation of the hollow shank.

Question 8

What are the four types of cable terminals?

Answer 8

Ball (single or double shank)
Stud (short or long thread)
Fork
Eye

Question 9

What is a fairlead?

Answer 9

Used to guide control cables to prevent contact with the structure.

Question 10

How does a pressure seal work with a cable?

Answer 10

The seals are filled with grease which allows the cable to pass freely with no loss of pressurisation.

Question 11

What does a turnbuckle assembly consist of?

Answer 11

Two threaded terminals and a threaded barrel.

Question 12

Why are turnbuckles fitted into a cable system?

Answer 12

To make minor adjustments in length or tension.

Question 13

How is the barrel with the left hand thread be identified in a turnbuckle.

Answer 13

By a groove or knurl around that end of the barrel.

Question 14

What does a cable tension regulator ensure?

Answer 14

Maintains uniform tension despite temperature and condition change.

Question 15

How many springs can a compensating unit of a tension regulator be manufactured with?

Answer 15

1 or 2.

Question 16

What is important to ensure before working on a control run?

Answer 16

The cable tension regulator is locked out or ‘snubbed’.

Question 17

What is the benefit of using a cable and conduit over levers, rods, chains etc.

Answer 17

They can be bent to pass through the strucutre.

Question 18

What are teleflex and bowden and example of?

Answer 18

Cable and conduit control.

Question 19

What does a teleflex control cable consist of?

Answer 19

Tension wire wound in a continuous left or right helix which can engage with gear teeth at the ends of the cable.

Question 20

What three types of teleflex cable are available for aircraft use?

Answer 20

DS 23/2 (known as 2)
DS 380
DS 169330.

Question 21

What is the minimum breaking load of DS 23/2 teleflex?

Answer 21

204kg.

Question 22

What direction is the helix of DS 23/2?

Answer 22

Left hand.

Question 23

What differs DS380 from DS 23/2?

Answer 23

Fitted with high tensile steel inner wire instead of compression wire.

Question 24

What direction of helix is DS380 and what is the minimum breaking load?

Answer 24

Right hand

454kg

Question 25

What is the only thing that makes DS 169330 different to DS380.

Answer 25

The spacer wire has been removed from the design.

Question 26

Where would you use DS 169330?

Answer 26

Hot areas of the aircraft up to 350 degrees C.

Question 27

When is a sliding end fitting used?

Answer 27

Where it is not neccesary to convert the push pull into a rotary movement.

Question 28

What are the limitations of a single entry unit?

Answer 28

270 degrees of travel and minimum 40 degrees of engagement.

Question 29

What is an anti torsion tube and where would you find one?

Answer 29

Prevents the cable turning in the conduit and can be found in the place of a spent travel tube.

Question 30

What is a straight lead unit?

Answer 30

Where the cable passes straight through and only engages in a few teeth.

Question 31

Where can swivel joints be installed?

Answer 31

Where the rotary movement of the control lever doesn’t exceed 90 degrees.

Question 32

How can damage to rigid conduit be repaired?

Answer 32

Insert a new section

Question 33

How must the cable be cleaned if it becomes dirty?

Answer 33

Cleaned in kerosene, wiped dry with a non fluffy cloth and re-lubricated.

Question 34

When fitting a cable what excess must you cut it with?

Answer 34

2 inches.

Question 35

Is a bowden cable push or pull?

Answer 35

Pull

Push is provided with a spring.