問題一覧
1
Chemical oxidation is the
direct combination of a metal with the oxygen in the atmosphere
2
Oxidation rate of a metal usually
increase with an increase in temperature
3
In the galvanic action process
the anode always corrodes
4
In the process of crevice corrosion, the anodic are is at the
the bottom of the crevice
5
When a metal is in contact with a fluid which promotes the growth of
microbiological
6
contaminants , such as in kerosene fuel and toilet waste fluids
microbiological corrosion is a present danger
7
Intergranular corrosion is caused by
incorrect heat treatment
8
Magnesium alloys
are not susceptible to intergranular corrosion
9
is a microbial fungal growth in kerosene fuel
Hormocoins resinae
10
Intergranular corrosion
often cannot be detected and has no visual surface indication
11
can be recognized on aluminum alloys by the appearance of grayish powder fuzzy deposit or a whiskery growth.
Mercury contamination
12
The oxide film formed on the surface of aluminium is
non-porous
13
Corrosion will spread more rapidly when metals are exposed to
high temperatures
14
Corrosion at the grain boundaries is called
intergranular
15
attack along the grain boundaries, or immediately adjacent to grain boundaries
Intergranular corrosion
16
Intergranular corrosion can be confirmed by
X-ray inspection
17
Stress corrosion is
corrosion due to fretting
18
the tendency of metals to revert to the thermodynamically more stable, oxidized, state
Corrosion
19
is another name for electrolytic, electrochemical or dissimilar metal corrosion
Galvanic corrosion
20
• Pitting corrosionis a form of extremely localized corrosion that leads to the creation of small holes in the metal may be caused by
localized damage to protective coating
21
Corrosion caused by galvanic action is the result of
contact between two dissimilar metals
22
Microbiological corrosion refers to corrosion and ensuing loss of metal caused by
biological organisms
23
Corrosion may be recognised by the appearance of ‛cocoa’ powder staining on steels is called
Fretting corrosion
24
NOT one of the conditions for corrosion to occur.
The presence of a cladding film is
25
The appearance of corrosion on Steel is normally
reddish brown (rust)
26
The appearance of corrosion on Aluminium alloy is normally as
whitish powder
27
is not one of the listed condition for corrosion to be occurred
torque load
28
A BA thread has a thread angle of
47 ½ degree
29
On a double -start thread the
lead is twice the pitch
30
Aircraft bolts are usually
class 3 fit
31
To measure an external thread , normally
a plain ring or caliper gauge is used
32
The female threads are subjected mainly to
compression force
33
A double start thread will travel axially
twice as far in one complete turn as one engaged with a single thread of similar pitch
34
Go and NOT GO screw gauges are used to check that an
internal thread is correct
35
Studs which have a size larger thread at one end are called
stepped studs
36
All threaded fasteners consist of
the male thread and female thread
37
The male threads are subjected mainly to
tension force
38
The difference between fine threads and
coarse threads that coarse threads are easier to assemble and misalignment is rare
39
allows you to turn the nut all the way down using only your fingers
A class 1 fit
40
may be considered as an inclined plane or wedge wrapped around a cylinder or shaft to form a helix
A screw
41
Crinkle washers are often used in lightly loaded applications in instrument and
electrical installations
42
Washers have one or more tabs projecting from the external diameter; they may also be ganged for locking two or more nuts ,known as
Tab washers
43
Locking wire is used only
once
44
Spring washers are available in two forms as
a single coil or as a double coil
45
Any locking wire damaged during installation will be weakened and must be
replaced
46
Wire sealing must be accomplished with the locking wire specified in the
aircraft maintenance manual
47
Rollpins must be used only
one time
48
There are basically two types of thread inserts available. One is known as
thin wall insert
49
The reason why the two-nut system is effective because it is
resisting self-loosening due to the way the threads are jammed together
50
A ‘Kayloc’ nut is a type of
stiffnut
51
A type B self tapping screws i
blunt point
52
Aluminum alloy bolts usually
anodized
53
When more than one anchor nut is attached to a plate , they are referred to as
strip nuts
54
Studs are used
where it is not possible to drill through both components for the fitting of blots
55
clevis bolt in a control cable fork end would be loaded in
shear
56
A British close tolerance bolt is identified by
hexagon headed or have 100˚counter sunk head
57
Aircraft bolts are always manufactured in
class 3, medium fit
58
conical shake proof washers are used for locking
countersunk screws
59
In many high load joints, where higher load distribution is required,
barrel nuts(or floating nuts). are often used
60
Tri-wing screws are easy to identify as they are the
three-point slots
61
A letter for British standard blot indicates
the shank diameter
62
A bolt with a single raised dash on the head is classified as an
AN corrosion-resistant steel bolt
63
A bolt with a two raised dash on the head is classified as an
Aluminium alloy bolt
64
A bolt with an X inside a triangle on the head is classified as
Steel close tolerance bolt
65
The screws differ from bolts in that they are generally
made from lower-strength materials
66
Wire locking also known as
safety wiring
67
Many fasteners have holes drilled in the heads to
allow fasteners to be locked by safety wire
68
describes all the various types of fastening device employed in the construction of an aeroplane
Fastener
69
The three principal parts of a bolt are
the head, thread, and grip
70
are used in structure that is required to be fluid tight
Double angle countersunk rivets
71
A rivet made from
5056 aluminum alloy is identified with a cross on the head
72
Flush head or countersunk rivets have an angle of
78-120 degrees countersink
73
2017 & 2024 rivets must be
used immediately or refrigerated after heat treatment
74
A rivet with a plain head is classified as
1100 (A)
75
Hoses for highly pressure applications are made from
synthetic rubber liner
76
Rigid pipe flaring has the purpose of
preventing the end of the pipe from slipping and providing fluid tight seal
77
The rigid pipes on gas turbine engines are made from
stainless steel
78
Flexible lines must be fitted with a slack of
5-8% of the length
79
Flexible sealing element subject to motion is a
packing
80
All aircraft high-pressure hoses have a maximum working pressure of at least
3000 1500
81
is a legible marking parallel to the longitudinal axis of a hose and is used to determine the straightness of the hose.
The lay line
82
Replacement tubing should be of the same size and material as
the original line
83
Pipe manufacture to American AN specifications have an induced flare angle of
74°
84
is used extensively on gas turbine engine fuel systems and high pressure hydraulic systems
Stainless steel tubing
85
The tubing used is generally of the seamless type and is specified by
material, outside diameter and wall thickness
86
The 1100 or 3003 aluminum alloy lines are used fo
fuel lines