問題一覧
1
what do you do when removing tires?
1. deflate tire before removing 2. check tire pressure when tires are cool 3. clean and inspect tires for damage 4.DO NOT use IMPACT tools on A/C
2
what is the most critical area on a wheel?
bead seat area
3
what is a fusible plug?
when enough heat is transferred into the wheel, it will melt the centre of the fusible plugs •fusible plug bleeds off tire pressure before explosion
4
how are tires classified
1. type 2. size 3. ply rating ex. “ 30 X 12.5 R 14 “
5
tire rims types
1. removable flange 2. one piece drop centre 3. split
6
what are chines used for?
deflects water away from the engines
7
when do you check tire pressure?
when tires are cool
8
on a dual wheel assembly, what happens when one tire goes flat?
both wheel assemblies must be replaced
9
brakes convert ____ energy to ____?
kinetic, heat
10
how are tires classified?
tire size and ply rating
11
what does ply rating on aircraft tires represent?
the strength of the tire
12
what tools do you use to seperate a tire from the wheel ?
beed breaker
13
under what condition is a cut on the tire not acceptable?
1. cut on side wall through breaker cords 2. extending cord or fabric 3. deeper than 50 % of remaining groove
14
what do the colour marks “dots” on tires represent?
Green “vent holes” Red “light spot” Yellow on tube “heavy spot”
15
on a tubed tire, how do you reduce the possibility of pinching while mating wheel?
by inflating the tube slightly
16
on a dual wheel set, how many tires do you replace if 1 goes flat?
both tires
17
what is the most popular type of wheel used on aircraft ?
two piece drop center
18
how are tube wheels halves sealed?
O-ring
19
a removable flange wheel is secured by?
snap ring
20
the letter L stamped on the wheel indicates?
they are to be 180 degrees apart
21
any excess impact which appear as indentations on bearing cup is known as?
brinelling
22
what is the purpose of over pressure relief valve on rims?
the valve will rupture if pressure is too high
23
the relative strength of new aircraft tires is represented by?
the ply rating
24
wheel alignment is done on aircraft to ensure?
wheels track correctly, reduces wear
25
can a radial tire be replaced with bias ply tire of the same size?
you cannot mix “bias” and “radial” tires
26
what is the most popular brake system for modern light aircraft’s ?
single disk brakes (modern light A/C)
27
what does a master cylinder do?
acts like a pump and provides hydraulic pressure to the “caliper” “each brake has its own master cylinder”
28
purpose of shuttle valve in a power brake system ?
shuts off main brake system pressure when emergency brake pressure is applied
29
purpose of anti skid system?
to prevent wheels from locking up when brakes are applied
30
how does the anti skid valve control the wheel speed?
by bleeding the brake pressure away from slow wheel to the reservoir
31
exposure to and or storage near which of the following is considered harmful to aircraft tires?
electrical equipment
32
why do manufactures recommend that the tires on spit wheel rims be defliated before removing the wheel from the axle?
“when working with aircraft wheels, ALWAYS release air from the tires before proceeding. BEFORE removing axle nut.
33
besides air in the brake system, what is the most likely cause of spongy brakes?
deteriorated flexible hose
34
a stripe or mark applied to a wheel rim and extending onto the sidewall of a tires is a ?
slippage mark
35
when bleeding aircraft brake, one of the indication that the air has been purged from the system is ?
firm brake pedals
36
when pushing left rudder pedal full forward?
no brakes will operate
37
debooster valves are used in brake system primarly to?
1. decrease the presure 2. increase the volume to “brake unit/ control unit” pressure “traded for volume”
38
to repar out of tolerance TOE-IN condition ?
wheel paths cross the forward of aircraft
39
the pressure source of the “power brake valve” is?
the main hydraulic system
40
if the longtidinal axis of the main landing gear wheel assembly insersect aft of the aircraft, wheels can be termed as?
Tow-Out
41
what is the most common type of bearing used on a wheel installation?
tapered roller bearing
42
the light side of a wheel half is identified by?
letter “L”
43
what kind of damage does the bearing in the picture have?
spalling
44
how do auto brakes work?
auto breaking unit controls the braking pressure for the best deceleration rate
45
what does 8 in 8.00 x 6 represent on type 3 tires?
“max width” of the tire
46
most commonly used information on the tire sidewall are?
1. tire size 2. part number 3. serial number
47
why are the tubes slightly inflated before mating the wheel halves?
reduces the posibility of pinching the tube with wheel halves
48
the hydraulic component that automaticall directs fluid from either normal sources or emergency
shuttle valve
49
what is the purpose of the booster brake system?
boosts braking pressure to caliper as brake is applied to the pedals “for aircraft that need more braking force”
50
when does the anti skid system disarm?
when all wheels have slowed below 20mph
51
why do manufactures recommend that the tires on split wheel rims be deflated before removing the wheel from axle?
as a safety precaution in case the wheel halves bolts are damaged or weakened
52
to repair out of tolerance TOE-IN condition
add, remove or change location of washers at the centre of the scissor link
53
any excessive impact which appears as “indentations on bearing cup” known as?
Brinelling
54
over pressure relief valve (OPR)
it uses pressure to detect an over pressure situation instead of heat “if pressure is exceeded in a predetermined value, disk will rupture in valve, releasing pressure before explosion occurs
55
wheel rim disassembly
1. use stem tool, remove stem from tire (ensures air drained from tire) 2. use bead breaker tool to seperate the tire from the wheel 3. DO NOT USE pry bars, screw drivers and unapproved tools
56
3 different types of bead breakers
1. mechanical 2. hydraulic 3. bead breaker installed on arbour press
57
what to look for when inspecting tires
cracks, dents, abrasions, corrosion 10x -15x magnifying glass required
58
after using a degreasing agent and long bristle brushes to clean bearings. what is the correct method to use compressed air to clean bearings ?
through bearings
59
most common tire types
9 types, 3 most common type 3 type 7 type 8
60
tube and tubeless tires
1. tube tires “not air tight, tire liner must be smooth” 2. tubeless tire “air tight, dosent require tube, must be installed on sealed wheel
61
grooves in the rubber do?
prevent hydroplaning
62
what do breaker cords do?
• warns operator he is dangerously close to the carcass of the tire • usually two layers of breaker cords • damage beyond second breaker layer means replacement of tire
63
what is a check?
chevron shaped cuts in tire tread
64
how to adjust “tow in and tow out”
•adding or subtracting “tapered shims” between axle and leg on sprint steel landing gear systems •adjust washer & scissor links on OLEO type
65
what are “shoe brakes”
same as car rear brakes “used on older aircraft”
66
types of single disk brakes
1. floating disk 2. fixed disk
67
what are linings?
linings or brake pads squeeze the brake disk to stop wheel made from organic material with high co-efficient of friction
68
multiple disk brakes
work in same manner as single disk brakes, but have more rotors and more stators
69
multi disk brakes are used on?
larger aircraft
70
segmented rotor disk brakes
multiple disk brake, several segmented plates in rotors •improved cooling, more efficient and longer braking action
71
carbon brakes
multiple disk brake that uses thick carbon composite disc as a brake rotor • “absorbs more kinetic energy, light weight, dissipates heat well, longer life span”
72
power brakes
used in large AC
73
emergency brake
in the case of a main brake system failure, the pilot can select the emergency brake control valve “allows emergency system to apply brakes”