11.2a Airframe Structures - General Concepts Flashcards
1
Q
What causes fatigue in civil air transportation structures?
A) Wind shear
B) Pressurisation cycles
C) Cabin noise
A
B) Pressurisation cycles
2
Q
What design philosophy do aircraft structures follow?
A) Distributed load theory
B) Stressed skin philosophy
C) Modular frame theory
A
B) Stressed skin philosophy
3
Q
Which of the following is a Principal Structural Element (PSE)?
A) Seats
B) Wings
C) Landing gear doors
A
B) Wings
4
Q
Why is a PSE important?
A) It provides lift
B) It supports the navigation system
C) Its integrity is essential to maintain overall structural integrity
A
C) Its integrity is essential to maintain overall structural integrity
5
Q
Which of the following is not mentioned as a PSE?
A) Window shades
B) Spar caps
C) Door frames
A
A) Window Shades
6
Q
What are flight limit loads?
A) Average service loads
B) Loads beyond ultimate design
C) Maximum loads expected in service
A
C) Maximum loads expected in service
7
Q
How are ultimate limit loads determined?
A) Adding a constant to the limit load
B) Dividing the limit load by a factor
C) Multiplying the flight limit load by a factor of safety
A
C) Multiplying the flight limit load by a factor of safety
8
Q
Where can the criteria for large aircraft structural standards be found?
A) FAA Circular 16
B) CS-25 Certification Specifications
C) ICAO Volume 1
A
B) CS-25 Certification Specifications
9
Q
Aircraft structural members are primarily designed to carry:
A) End loads
B) Torsional loads only
C) Side loads
A
A) End loads
10
Q
What is tension?
A) Stress resisting twisting
B) Stress resisting pulling and extension
C) Stress resisting lateral movement
A
B) Stress resisting pulling and extension
11
Q
What does compression stress do to a part?
A) Extends and stretches it
B) Twists it
C) Squeezes and shortens it
A
C) Squeezes and shortens it
12
Q
What causes torsion stress?
A) Torque or twisting
B) Compression from both ends
C) Shear in multiple planes
A
A) Torque or twisting
13
Q
What stress resists one layer moving relative to another?
A) Bending
B) Torsion
C) Shear
A
C) Shear
14
Q
Bending stress is a combination of:
A) Tension and torsion
B) Shear and compression
C) Compression and tension
A
C) Compression and tension
15
Q
What do fasteners in aerospace structures typically experience?
A) Bending stress
B) Shear stress
C) Tension stress
A
B) Shear stress
16
Q
What are cowling and fairing primarily designed for?
A) Aerodynamic profile, not load carrying
B) Lifting capacity
C) Housing electrical systems
A
A) Aerodynamic profile, not load carrying
17
Q
What must be considered when designing each aircraft part?
A) Electrical resistance
B) Aesthetic appearance
C) Physical characteristics of its material
A
C) Physical characteristics of its material
18
Q
What is the process of determining the load a part must carry called?
A) Quality assurance
B) Stress analysis
C) Load certification
A
B) Stress analysis
19
Q
Why is classifying aircraft structures into categories important?
A) To simplify assembly
B) To evaluate damage and guide appropriate repairs
C) To reduce fuel consumption
A
B) To evaluate damage and guide appropriate repairs
20
Q
Where can technicians find the category assigned to a particular aircraft structure?
A) Pilot handbook
B) Maintenance logbook
C) Manufacturer manuals
A
C) Manufacturer manuals
21
Q
How many structural categories are there in aircraft classification?
A) Two
B) Three
C) Four
A
B) Three
22
Q
Which of the following is a structural category in aircraft?
A) Operational structure
B) Mechanical structure
C) Tertiary structure
A
C) Tertiary structure
23
Q
What consequence can result from the failure of a primary structure?
A) Paint damage
B) Inability to deploy landing gear
C) Loss of control over the aircraft
A
C) Loss of control over the aircraft
24
Q
Which is not listed as a possible consequence of primary structure failure?
A) Harm to occupants
B) Change in cabin lighting
C) Unintended operation
A
B) Change in cabin lighting
25
What is an example of a primary structural component?
A) Fairing
B) Engine mount
C) Cabin carpet
B) Engine mount
26
What are Principal Structural Elements (PSEs) responsible for?
A) Lighting and display systems
B) Carrying loads from flight, ground, and pressurization
C) Providing insulation
B) Carrying loads from flight, ground, and pressurization
27
What is a Structurally Significant Item (SSI)?
A) A decorative component
B) A primary structure listed for special inspections
C) A minor component not needing maintenance
B) A primary structure listed for special inspections
28
Why might primary structures require special inspections?
A) They are new technologies
B) They influence engine calibration
C) They play a critical role in aircraft integrity
C) They play a critical role in aircraft integrity
29
Which structure is described as having strength exceeding design requirements?
A) Tertiary structure
B) Secondary structure
C) Primary structure
B) Secondary structure
30
What is an example of a secondary structural component?
A) Wing rib
B) Engine cowling
C) Window curtain
A) Wing rib
31
What distinguishes secondary structure from primary?
A) It is more decorative
B) It has no structural value
C) It is structurally significant but not critical like primary
C) It is structurally significant but not critical like primary
32
What does tertiary structure mainly consist of?
A) Primary floor beams
B) Lightly stressed components
C) Engine parts
B) Lightly stressed components
33
Which of the following is considered a tertiary structure item?
A) Fairing
B) Wing spar
C) Fuselage frame
A) Fairing
34
What is the primary structural design philosophy of aircraft manufacturers?
A) To minimize noise pollution
B) To produce high-quality aircraft using the best design, materials, and techniques
C) To increase airport capacity
B) To produce high-quality aircraft using the best design, materials, and techniques
35
What is the purpose of incorporating fail-safe load transfer, damage tolerance, and fatigue indexing in the design phase?
A) To reduce engine noise
B) To improve cabin aesthetics
C) To ensure safe operation throughout the aircraft’s lifetime
C) To ensure safe operation throughout the aircraft’s lifetime
36
Which FAA document is referenced for evaluating structural design safety provisions?
A) FAA AC 21-1A
B) FAA AC 23-13A
C) FAA AC 33-2B
B) FAA AC 23-13A
37
What does the fail-safe method rely on?
A) Painting structural parts in bright colors
B) Duplication of certain structural members
C) Using cheaper materials to save cost
B) Duplication of certain structural members
38
What is true about a structure once a failure has occurred in a fail-safe component?
A) It becomes stronger
B) It becomes fail-proof
C) It is no longer fail-safe
C) It is no longer fail-safe
39
In a fail-safe spar design, what ensures continued load support if one part breaks?
A) Increased fuel efficiency
B) The other spar section carries the load
C) Use of non-metallic materials
B) The other spar section carries the load
40
Why are passenger windows considered fail-safe?
A) They are tinted
B) They are easy to replace
C) Both panes can withstand pressurisation loads
C) Both panes can withstand pressurisation loads
41
What is a major drawback of the fail-safe concept?
A) Increased maintenance time
B) It reduces visibility from windows
C) It adds extra weight
C) It adds extra weight
42
Which concept has largely replaced the fail-safe approach in modern aircraft?
A) Weight-saving concept
B) Damage tolerance
C) Thermal resistance
B) Damage tolerance
43
What does the safe-life concept predict?
A) Cabin air quality over time
B) Fuel efficiency per cycle
C) How long a structure can serve before fatigue damage
C) How long a structure can serve before fatigue damage
44
During safe-life testing, what is the airframe taken to?
A) Maximum cabin pressure
B) Minimal wing loading
C) Fatigue damage and then catastrophic failure
C) Fatigue damage and then catastrophic failure
45
What proportion of the maximum test cycles or hours is typically assigned as the safe-life?
A) Half
B) One-third
C) All
B) One-third
46
What factor can reduce a component’s safe-life despite predictions?
A) Smooth flight routes
B) Aesthetic modifications
C) Frequent short-haul flights in corrosive environments
C) Frequent short-haul flights in corrosive environments
47
What does the damage tolerance concept ensure about structural damage?
A) It is undetectable
B) It causes instant failure
C) It can be withstood until detected at inspection
C) It can be withstood until detected at inspection
48
What is the multiple load path method designed to avoid?
A) The need for inspections
B) Use of fasteners
C) Failure of large, highly stressed members
C) Failure of large, highly stressed members
49
What is the function of crack limiting joints?
A) Make maintenance easier
B) Limit the spread of cracks and allow detection during inspections
C) Reduce drag
B) Limit the spread of cracks and allow detection during inspections
50
What is a key limitation of the damage tolerance concept?
A) Overuse of heavy materials
B) Lack of durability
C) Dependence on human inspection
C) Dependence on human inspection
51
How many main structural units does an aircraft have?
A) Three
B) Five
C) Seven
B) Five
52
Which of the following is not listed as one of the five main structural units of an aircraft?
A) The cabin interior
B) The landing gears
C) The flight control surfaces
A) The cabin interior
53
Why is the aircraft divided into zones and reference areas?
A) To improve in-flight entertainment systems
B) To simplify painting and branding
C) To identify component locations and calculate weight distribution
C) To identify component locations and calculate weight distribution
54
What are the types of reference planes used in aircraft structure?
A) Static, Dynamic, and Rotational planes
B) Vertical, Horizontal, and Longitudinal planes
C) Forward, Backward, and Cross-sectional planes
B) Vertical, Horizontal, and Longitudinal planes
55
What measurement units might be used for reference planes by manufacturers?
A) Inches, centimetres, and millimetres
B) Feet, yards, and kilometres
C) Pounds, gallons, and amperes
A) Inches, centimetres, and millimetres
56
What standard is the Zonal Identification System based on?
A) FAA Part 43
B) ISO 9001
C) ATA Specification
C) ATA Specification
57
How many major zones are there in the ATA Zonal Identification System?
A) Six
B) Eight
C) Ten
B) Eight
58
Which major zone number represents the left wing?
A) 500
B) 600
C) 300
A) 500
59
What does Zone 400 correspond to?
A) Landing gear
B) Power plants and struts
C) Empennage
B) Power plants and struts
60
What does the second digit of a zone code represent?
A) Zone letter
B) Component serial number
C) Sub-major zone
C) Sub-major zone
61
On large aircraft, what is the range of sub-major zone second digits?
A) 1 to 4
B) 1 to 6
C) 1 to 9
C) 1 to 9
62
How are sub-major zones typically numbered for left and right sides?
A) Even for left, odd for right
B) Random
C) Odd for left, even for right
C) Odd for left, even for right
63
What does the third digit in the zone code identify?
A) Manufacturing batch
B) Specific zone location
C) Access door type
B) Specific zone location
64
How are zones usually numbered?
A) Aft to forward
B) Outboard to inboard
C) Forward to aft, inboard to outboard, bottom to top
C) Forward to aft, inboard to outboard, bottom to top
65
What does a letter after the zone number indicate?
A) Emergency part access
B) Panel or door subzone
C) Operator initials
B) Panel or door subzone
66
What do the first and second letters in door/panel identification describe?
A) Serial number and material type
B) Manufacturing date and inspection interval
C) Location: forward-aft/inboard-outboard and side (left or right)
C) Location: forward-aft/inboard-outboard and side (left or right)
67
What is the purpose of the Station Identification System?
A) Identify component material
B) Identify points on the aircraft using a coordinate system
C) Assign inspection levels
B) Identify points on the aircraft using a coordinate system
68
What is a Body or Fuselage Station (BS or FS)?
A) A horizontal axis used to mount engines
B) A vertical plane at a right angle to the centreline
C) A checkpoint for cabin pressurisation
B) A vertical plane at a right angle to the centreline
69
From where is the body station measured?
A) Wing root
B) Nose landing gear
C) A point in front of the nose
C) A point in front of the nose
70
What do Buttock Lines (BL) represent?
A) Aircraft engine locations
B) Vertical planes parallel to the centreline
C) Wing thickness ratios
B) Vertical planes parallel to the centreline
71
What does “L BBL” indicate in station coordinates?
A) Load bearing limit
B) Left body buttock line
C) Lower body bolt line
B) Left body buttock line
72
What are Waterlines (WL)?
A) Lines used in the fuel system
B) Aircraft paint guide lines
C) Horizontal planes at right angles to stations and butt lines
C) Horizontal planes at right angles to stations and butt lines
73
Where can the zero waterline sometimes be located?
A) Below the landing gear
B) Inside the cockpit
C) On top of the fuselage
A) Below the landing gear
74
Wing stations are measured from which reference point?
A) The tip of the wing
B) The center of gravity
C) A butt line or wing rib 1
C) A butt line or wing rib 1
75
What do Component Stations (CS) usually apply to?
A) Windows and seats
B) Landing lights
C) Flying control surfaces, nacelles, and pylons
C) Flying control surfaces, nacelles, and pylons
76
What is true about component station coordinates?
A) They are shared with the wing stations
B) They have their own butt line datum
C) They are only used during aircraft painting
B) They have their own butt line datum
77
Which of the following is not listed as a structural member in an aircraft?
A) Bulkheads
B) Stringers
C) Valves
C) Valves
78
What is the primary purpose of stress analysis in aircraft design?
A) To check the comfort of passengers
B) To ensure the structure can handle expected loads
C) To evaluate fuel efficiency
B) To ensure the structure can handle expected loads
79
What does tension resist?
A) Twisting force
B) Crushing force
C) Pulling-apart force
C) Pulling-apart force
80
Tension is commonly measured in which units?
A) Gallons and litres
B) Newtons or pounds-force
C) Degrees Celsius or Fahrenheit
B) Newtons or pounds-force
81
How is tensile strength calculated?
A) Load ÷ cross-sectional area
B) Load × height
C) Weight ÷ surface area
A) Load ÷ cross-sectional area
82
What does compression stress resist?
A) Shearing motion
B) Crushing force
C) Bending force
B) Crushing force
83
What type of stress causes twisting in aircraft components?
A) Bending
B) Torsion
C) Hoop
B) Torsion
84
When does torsion stress occur in a rudder?
A) When it’s at rest
B) When it’s painted
C) When it is deflected
C) When it is deflected
85
What type of stress occurs when one layer of material slides over another?
A) Shear
B) Torsion
C) Compression
A) Shear
86
Which structural fastener is designed to resist shear forces?
A) Bolts
B) Rivets
C) Screws
B) Rivets
87
What is gradually replacing riveted joints in modern aircraft?
A) Laser welding
B) Adhesive bonding
C) Steel cables
B) Adhesive bonding
88
How is stress defined in materials science?
A) Load × length
B) Change in shape over time
C) Force ÷ cross-sectional area
C) Force ÷ cross-sectional area
89
What are the units used to measure stress?
A) Newtons per meter squared, Pascals, or pounds per square inch
B) Volts and amperes
C) Litres per hour
A) Newtons per meter squared, Pascals, or pounds per square inch
90
Bending stress is a combination of which two types of stress?
A) Shear and hoop
B) Tension and compression
C) Torsion and strain
B) Tension and compression
91
During flight, what type of stress occurs on the upper surface of the wing?
A) Compression
B) Tension
C) Shear
A) Compression
92
What is hoop stress associated with?
A) Twisting of control surfaces
B) Bending of the landing gear
C) Cabin pressurisation
C) Cabin pressurisation
93
In a pressurised aircraft fuselage, hoop stress acts:
A) Axially
B) Perpendicularly
C) Circumferentially
C) Circumferentially
94
How does hoop stress compare to longitudinal stress at the same pressure?
A) It is half the value
B) It is the same
C) It is twice the value
C) It is twice the value
95
What is strain?
A) The amount of pressure applied to a surface
B) A ratio of deformation to original length
C) The time taken to fail under load
B) A ratio of deformation to original length
96
What causes fatigue damage in aircraft components?
A) Static loads
B) High temperatures
C) Cyclic or alternating loads
C) Cyclic or alternating loads
97
What does fatigue damage usually begin as?
A) A dent
B) A gouge
C) A tiny crack
C) A tiny crack
98
Which of the following is a common initiator of fatigue failure?
A) Lubrication
B) Surface damage like a scratch
C) Uniform pressure
B) Surface damage like a scratch
99
Why is effective drainage and ventilation important in aircraft structure?
A) To increase fuel capacity
B) To prevent fluids from getting trapped in crevices
C) To reduce the weight of the fuselage
B) To prevent fluids from getting trapped in crevices
100
How are fluids directed to drain holes in the lower fuselage?
A) Through external grooves
B) By gravity only
C) By longitudinal and cross-drain paths through stringers and frames
C) By longitudinal and cross-drain paths through stringers and frames
101
Where are drain holes commonly located?
A) Wing tips
B) Top of the fuselage
C) Lower fuselage
C) Lower fuselage
102
What is the function of the "bilge-like" valves on the aircraft?
A) To release engine oil
B) To seal fuel tanks
C) To allow drainage when the aircraft is depressurised
C) To allow drainage when the aircraft is depressurised
103
What happens to the drain valve when the aircraft becomes pressurised?
A) It remains open
B) It closes
C) It releases vapour
B) It closes
104
Why do the valves close during flight?
A) To prevent water from entering
B) To retain hydraulic pressure
C) To prevent air loss due to cabin pressurisation
C) To prevent air loss due to cabin pressurisation
105
What determines the specific type of drain valve used on an aircraft?
A) Size of the fuselage
B) Aircraft colour
C) Manufacturer's design
C) Manufacturer's design
106
Where should an engineer refer for details about drain valves on a specific aircraft?
A) Flight manual
B) Airport operations manual
C) Aircraft Maintenance Manual (AMM)
C) Aircraft Maintenance Manual (AMM)
107
Why must cavities in the structure that may contain flammable vapours be ventilated?
A) To reduce humidity
B) To prevent corrosion
C) To allow evaporation of vapours
C) To allow evaporation of vapours
108
What is the purpose of vent pipes in the aircraft?
A) To equalise cabin pressure
B) To provide a route for vapour to escape
C) To fill tanks with fuel
B) To provide a route for vapour to escape
109
What special ventilation feature might engine nacelles have?
A) Extra oxygen tanks
B) Ram air inlets and exit points
C) Sealed cavities
B) Ram air inlets and exit points
110
What must engineers ensure about designed ventilation openings?
A) That they remain painted over
B) That they are kept warm
C) That they are unobstructed
C) That they are unobstructed
111
Which regulation covers structural ventilation requirements?
A) CS-20
B) CS-25
C) CS-30
B) CS-25
112
How is air extracted from toilets and galleys?
A) Through drain valves
B) Using extract fans
C) By leaving windows open
B) Using extract fans
113
What happens to the air extracted from the toilet and galley areas?
A) It’s recycled into the cabin
B) It is filtered and stored
C) It is ejected overboard
C) It is ejected overboard
114
What does the provision for system installation depend on?
A) Number of passengers
B) Type of system and aircraft design
C) Paint scheme of the aircraft
B) Type of system and aircraft design
115
What are some key factors considered in system installation provisions?
A) Seat comfort and paint finish
B) Usage, serviceability, operability, and maintainability
C) Luggage capacity and in-flight meals
B) Usage, serviceability, operability, and maintainability
116
How are cockpit indicators typically installed?
A) Glued in place
B) Permanently riveted
C) Securely mounted with ease of removal in mind
C) Securely mounted with ease of removal in mind
117
Why must aircraft designers provide access to system components?
A) To allow passengers to view them
B) For inspection and regular servicing
C) To reduce the weight of the aircraft
B) For inspection and regular servicing
118
What kind of components must be easily accessible for regular maintenance?
A) In-flight entertainment screens
B) Window blinds
C) Filters, fluid level checkers, and lubrication points
C) Filters, fluid level checkers, and lubrication points
119
What are LRUs?
A) Load-bearing units
B) Line Replaceable Units
C) Landing Runway Units
B) Line Replaceable Units
120
Why is it important that LRUs be easily replaceable?
A) To improve aircraft fuel efficiency
B) To reduce painting time
C) To lower maintenance time and costs
C) To lower maintenance time and costs
121
Why is grouping system components into a single bay beneficial?
A) Reduces aircraft drag
B) Makes loading cargo easier
C) Improves access and reduces maintenance time
C) Improves access and reduces maintenance time
122
How are control signal cables typically arranged in modern aircraft?
A) Loosely coiled and left unprotected
B) Hung from the ceiling
C) Grouped into looms and secured with ties and stand-offs
C) Grouped into looms and secured with ties and stand-offs
123
What is the advantage of grouping computers in a specific fuselage section?
A) Better control of environmental conditions and accessibility
B) Faster Wi-Fi speeds
C) Easier refuelling procedures
A) Better control of environmental conditions and accessibility
124
Why is maintainability a key consideration in system installation?
A) It improves flight speed
B) It affects fuel burn
C) It helps keep aircraft serviceable and reduces downtime
C) It helps keep aircraft serviceable and reduces downtime
125
What impact does easier component access have for aircraft operators?
A) Increases takeoff speed
B) Saves time and lowers maintenance costs
C) Decreases cargo space
B) Saves time and lowers maintenance costs
126
What is the primary purpose of lightning protection on an aircraft?
A) To improve aerodynamic performance
B) To prevent corrosion
C) To reduce the risk of damage from lightning strikes
C) To reduce the risk of damage from lightning strikes
127
What basic material provides lightning protection in traditional aircraft?
A) Rubber coating
B) The external metal structure
C) Carbon fibre
B) The external metal structure
128
How are composite aircraft protected from lightning?
A) With additional rivets
B) By using metallic paint, conductive mesh, or coatings
C) By painting the aircraft white
B) By using metallic paint, conductive mesh, or coatings
129
What is one function of the aircraft’s external structure in relation to lightning strikes?
A) It acts as an antenna
B) It amplifies electric fields
C) It shields internal areas and systems
C) It shields internal areas and systems
130
What should be done first after a lightning strike is suspected?
A) Check passenger luggage
B) Perform a general walk-around inspection
C) Reboot all electrical systems
B) Perform a general walk-around inspection
131
What are the two main types of lightning strike damage?
A) Physical and hydraulic
B) Direct and indirect
C) Permanent and temporary
B) Direct and indirect
132
What is a characteristic of direct lightning damage?
A) Faulty software
B) Surface burns, melting, or distortion
C) Cabin pressure imbalance
B) Surface burns, melting, or distortion
133
What kind of damage results from electrical transients affecting wiring and systems?
A) Indirect damage
B) Direct damage
C) Mechanical fatigue
A) Indirect damage
134
What should be inspected after a lightning strike causes a system malfunction?
A) Just the affected area
B) The entire airframe
C) The full defective system
C) The full defective system
135
What is a typical visible sign of a lightning strike on the aircraft?
A) Oil stains
B) Small circular melt or scorch marks
C) Dents from hail
B) Small circular melt or scorch marks
136
What size are typical lightning scorch marks on an aircraft?
A) 1 mm
B) 3 mm
C) 10 mm
B) 3 mm
137
Which components are checked during a lightning strike conditional inspection?
A) Passenger seats and tray tables
B) External surfaces, static dischargers, electrical and hydraulic systems
C) Lavatories and cargo nets
B) External surfaces, static dischargers, electrical and hydraulic systems
138
Where are lightning strikes most likely to occur on an aircraft?
A) Under the cabin floor
B) Nose section, trailing edges, and wing/stabiliser extremities
C) Cockpit footwell
B) Nose section, trailing edges, and wing/stabiliser extremities
139
What can happen to aircraft components as a result of lightning discharge?
A) They lose structural integrity
B) They become magnetised
C) They inflate
B) They become magnetised
140
Which internal systems are most vulnerable to high-intensity lightning strikes?
A) Seatbelt systems and galley equipment
B) Fuel valves, generators, and power feeders
C) Air conditioning vents
B) Fuel valves, generators, and power feeders
141
What is the primary purpose of bonding on an aircraft?
A) To increase structural strength
B) To equalise electrical potential across components
C) To regulate fuel flow
B) To equalise electrical potential across components
142
What is the definition of grounding?
A) Connecting wires for better fuel economy
B) Connecting conductive objects to a return path or structure
C) Joining two pipes together
B) Connecting conductive objects to a return path or structure
143
Why is bonding essential in aircraft electrical systems?
A) To help detect faults
B) To ensure uniform paint thickness
C) To prevent static charge build-up and electrical arcing
C) To prevent static charge build-up and electrical arcing
144
Bonding provides a return path for which type of system?
A) Dual-wire systems
B) Three-phase systems
C) Single-wire electrical systems
C) Single-wire electrical systems
145
Which of the following is not a reason for bonding?
A) Minimising radar interference
B) Increasing cabin humidity
C) Reducing lightning damage
B) Increasing cabin humidity
146
Which item would typically not be used for bonding connections?
A) Nut plates
B) Flexible bonding jumpers
C) Plastic rivets
C) Plastic rivets
147
What must be done to ensure proper bonding resistance?
A) Apply insulating paint
B) Remove non-conductive coatings
C) Use rubber washers
B) Remove non-conductive coatings
148
What is the maximum bonding resistance value that is acceptable?
A) 0.25 Ω
B) 1.0 Ω
C) 0.025 Ω
C) 0.025 Ω
149
What is used as the primary return path for current in an aircraft?
A) The landing gear
B) The aircraft’s metallic structure
C) The fuselage insulation
B) The aircraft’s metallic structure
150
When grounding in fuel-vapour areas, what special condition applies?
A) Use ceramic terminals only
B) Only single ground points are allowed
C) Dual grounds must be used
C) Dual grounds must be used
151
How many terminals are allowed on one grounding stud?
A) Unlimited
B) No more than four
C) Only one
B) No more than four
152
What is the main challenge with bonding on composite aircraft structures?
A) They are too flexible
B) They have poor electrical conductivity
C) They corrode easily
B) They have poor electrical conductivity
153
How is bonding achieved on composite aircraft?
A) Through carbon tape only
B) Using embedded rivets
C) By integrating an aluminium mesh
C) By integrating an aluminium mesh
154
What is direct bonding in composite aircraft?
A) Bonding using two separate wires
B) Connecting to exposed mesh directly under the equipment
C) Connecting only during maintenance
B) Connecting to exposed mesh directly under the equipment
155
What is indirect bonding?
A) Using Wi-Fi signals to link components
B) Installing bonding wires to exposed mesh
C) Grounding to the wing tip only
B) Installing bonding wires to exposed mesh
