Fatigue and Stress | Wheels, Rims, and Tyres

Question 1

There are _ main types of wheels:

Answer 1

• Well-based
• Detachable flange
• Split hub

Question 2

Detachable flange tyres can have one side removed by ___

Answer 2

taking out a locking ring

Question 3

Wheels are generally made from ___

Answer 3

aluminium alloys

Question 4

Using aluminimum allows ___ space between the rim and the brake for cooling purposes

Answer 4

more

Question 5

___ ___ are fitted to the wheel rims to reduce the risk of excessive heating causing a retracted tyre to burst within the wheel well

Answer 5

Fusible inserts

Question 6

A fussible insert is ___

Answer 6

A hexagonal stud with bored centre and a rubber plug. They melt at a pre-set temperature to blow out the rubber plug and deflate the tyre, prior to an explosion

Question 7

The average life of a tyre is around ___ landings between remoulds, and around _ to _ retreads

Answer 7

100

2-3

Question 8

The most likely time for creep is when the tyre is ___

Answer 8

newly fitted

Question 9

Creep is the ___ movement of the tyre in relation to the wheel ___

Answer 9

circumferential flange

Question 10

An engineer should be consulted when when the creep exceeds ___

Answer 10

half of the distance of the creep mark

Question 11

A red band is a ___ mark

Answer 11

balance

Question 12

A grey/green mark is a ___, which allows

Answer 12

awl hole, trapped gas between plies to esacpe

Question 13

Up to 24 inches in diameter, _ inch(es) of creep is/are allowed

Answer 13

1 inch is

Question 14

Above 24 inches in diameter, _ inch(es) of creep is/are allowed

Answer 14

1.5

Question 15

A speed rating is present if the tyre is rated above ___ mph

Answer 15

160

Question 16

Tyres are normally inflated with the weight (off) the wheels and _% is added to compensate

Answer 16

off 4

Question 17

Air can escape through either ___

Answer 17

valve or carcass

Question 18

Air cannot escape through the ___ with tubeless tyres

Answer 18

carcass

Question 19

Cold tyres are rejected if they are over __% below pressure

Answer 19

10

Question 20

Betwen _% and __% below pressure, they can be reinflated and checked the next day, then rejected if they are still more than _% below

Answer 20

5 10 5

Question 21

A tyre below _% can be reinflated, but must be rejected if it reaches the same value by the next day

Answer 21

5

Question 22

Hot tyres are rejected if they are more than __% below the loaded pressure of other tyres on the same leg

Answer 22

10

Question 23

Under-inflated tyres wear most on their ___, and over-inflation leads to ___ wear

Answer 23

shoulders crown

Question 24

Tyres should be inflated with ___ as it has a reduced pressure change with altitude, though ___ ___ can also be used

Answer 24

nitrogen, dry air

Question 25

Nitrogen must be used to inflate tyres on aircraft over ___kg that have retractable landing gear

Answer 25

5700

Question 26

Typical inflation pressures are __ to __ psi for grass and ___ psi for paved

Answer 26

30 50 200

Question 27

The permissable load ___ as inflation pressure decreases

Answer 27

decreases

Question 28

Pre-flight inspection of tyres should include:

Answer 28

- Creep within limits - No cuts/scores/swelling/bulges - No embedded objects - No signs of heat damage - Correct inflation

Question 29

Tyres are classified by ___

Answer 29

- Load - Ply - Speed rating

Question 30

The ply rating identifies a tyre by its maximum recommended ___ and ___

Answer 30

load and pressure

Question 31

Ply rating is the index of tyre ___

Answer 31

strength

Question 32

Most tyres are ___ply, to ensure even load distribution, with multiple layers of nylon ply at alternating angles to the tread centreline

Answer 32

cross

Question 33

With radial tyres, the ply runs at __ degrees, which helps with cornering.

Answer 33

90

Question 34

High speed demands are covered by ____ the tread

Answer 34

reinforcing

Question 35

Radials are ___ flexible and can offer ___ weight, but tend to be ___ retreadable than a bias ply with weaker sidewalls.

Answer 35

more low less

Question 36

Tread is made from a compounded rubber that must resist ___

Answer 36

- Wear - Cutting - Chunking - Heat build up

Question 37

The tread includes the __ and __ of the tyre

Answer 37

crown shoulder

Question 38

The most common pattern is ___ tread

Answer 38

ribbed

Question 39

The ribs along the length of the circumference help with ___ ___ and grooves between them allow ___ ___

Answer 39

directional stability, water dispersal

Question 40

___ treads are best for unpaved airfields

Answer 40

Diamond

Question 41

You can go down to the depth of the pattern ( on patterned tyres), or the marker tie bar, or _mm above the bottom of the wear indicator on ribbed tyres, and they can be repaired several times

Answer 41

2

Question 42

A plain treaded tyre is at its limits when __ ___ is exposed

Answer 42

cushion rubber

Question 43

A layer of rubber that is designed to improve the adhesion between tread/ITF and the casing plies is called the ___

Answer 43

undertread

Question 44

During the retreading process, the ___ acts as the interface for the application of fresh tread rubber

Answer 44

undertread

Question 45

The basic strength of the tyre is provided by the ___ ___

Answer 45

casing plies

Question 46

Casing plies are layers of __ ___ coated with ___ ___ on both sides

Answer 46

fabric cord hi-modulus rubber

Question 47

Casing plies are held in place by being wrapped around the ___ to provide the casing ply turn up

Answer 47

beads

Question 48

The bead wire anchors the ___ to the ___ to ensure an airtight seal

Answer 48

tyre to the rim

Question 49

Beads are bundles of ___

Answer 49

high tensile steel wires

Question 50

The sidewall is the area of the tyre between the ___ and the ___

Answer 50

shoulder and the bead

Question 51

The sidwall is covered with a layer of special rubber treated with ___

Answer 51

anti-oxidants

Question 52

The sidewall protects the casing plies from the effects of ___ and offers resistance to ___ and ___

Answer 52

weathering cuts flexing

Question 53

Tubed tyres are inflated with a ___

Answer 53

rubber inner tube

Question 54

The tyre casing around a tubed tyre is similar to that of a ___ ___

Answer 54

tubeless tyre

Question 55

Tubed tyres are ___ subject to sudden blowouts

Answer 55

less

Question 56

The main problem with tubed tyres is ___ or ___ of the inflation valve after creep

Answer 56

bending breaking

Question 57

A tubeless tyre has __ inner tube

Answer 57

no

Question 58

Tubeless tyres are ___ to balance

Answer 58

easier

Question 59

There is __ rubbing during taxing, they are __C cooler when running and are vented to release air trapped in the casing.

Answer 59

less 10

Question 60

Tubeless tyres have a ___ risk of deflating through puncture

Answer 60

lower

Question 61

A tubeless tyre has a ___ casing

Answer 61

radial side casing