PRELIM AIRSYS Flashcards
(148 cards)
1
Q
tends to stretch a structural
member.
A
Tension or Tensile
2
Q
- Components that are designed to
resist compressive loads.
A
Struts
2
Q
Components designed to resist tensile loads
A
Ties
3
Q
are the opposite of tensile loads
and tend to shorten structural
members.
A
Compression
4
Q
- a force which tends to slide one
face of the material over an adjacent
face.
A
Shear
4
Q
- involves the three basic loadings:
Tension(outer), Compression(inner), and Shear(across).
A
Bending
5
Q
- designed to resist shear forces
A
Riveted joints
6
Q
- internal force inside a structural member which resists an externally applied force.
A
Stress
6
Q
- Twisting force that produce
Tension(outer), Compression(center)
and shear(across)
A
Torsion
7
Q
- occurs to thin sheet materialswhen they are subjected to end loads and to ties if subjected to compressive forces.
A
Buckling
8
Q
- the ratio of the change in length to the original length and is a measure of the deformationof any loaded structure
A
Strain
9
Q
the maximum load that the designer would expect the airframe or component to experience in service.
A
Design Limit Load (DLL)
10
Q
Design limit load for public transport aircrafts
A
2.5G
10
Q
Design limit load for aerobatic aircrafts
A
6G
11
Q
Design limit load for utility aircrafts
A
3.4G 3.8G
12
Q
When it is applied the aircraft structure must not suffer any permanent deformation and all flying control and other systems must function normally.
A
Proof load
13
Q
- it is the DLL multiplied by thesafety factor.
A
Design Ultimate Load(DUL)
14
Q
DUL Min. safety factor required
A
1.5
15
Q
the ratio of the ultimate load to the
limit load.
A
Safety factor
16
Q
defined as the minimum number of
flying hours, landings, cycles etc. which should elapse before a major
structural failure occurs.
A
safe life
17
Q
This is a structure having multiple
load paths which means that the
loads are shared by adjacent
members. Therefore if one part fails
the load it carried will now be carried
by the adjacent member for a limited
period.
A
fail safe structure
18
Q
- eliminates the extra structural
members by spreading the loading
of a particular structure over a larger
area.
A
Damage Tolerant Structure
19
Q
A method of locating components
on the aircraft must be established
in order that maintenance and
repairs can be carried out.
A
Station Numbers
19
Q
- A structure which is subjected to
continual reversals of loading will fail
at a load of less than would be the
case for a steadily applied load.
A
Fatigue
20
reference to a zero datum line
at or near the forward portion of
the aircraft.
Fuselage station lines
21
Vertical position from a groundline or horizontal datum.
Water Line (WL) or ButtockLine
22
are given in inches forward (“-”)
or aft (“+”) of the zero datum.
station numbers
23
- are measured from the centerline of the aircraft
Wing stations
24
Aircraft Structural Zoning System
Major zone
Major Sub-zone
Simply a zone
25
Zoning of large aircraft is specifiedby the Air Transport Association of America in the ATA-100 Specification.
Aircraft Structural Zoning System
26
Zone 100
Lower half of the fuselage to the rear pressure bulkhead (below the main cabin deck).
27
Lower half of the fuselage to the rear pressure bulkhead (below the main cabin deck).
Zone 100
28
Zone 200
Upper half of the fuselage to the rear pressure bulkhead.
29
Upper half of the fuselage to the rear pressure bulkhead.
zone 200
30
Empennage, including fuselage aft of the rear pressure bulkhead.
zone 300
31
zone 300
Empennage, including fuselage aft of the rear pressure bulkhead.
32
zone 400
Power plants and struts or pylons.
32
Power plants and struts or pylons.
zone 400
33
left wing
zone 500
33
zone 500
left wing
34
right wing
zone 600
35
zone 600
right wing
35
zone 700
Landing gear and landing gear doors.
36
Landing gear and landing gear doors.
zone 700
36
zone 800
doors
37
doors
zone 800
38
Reserved for uncommon differences between aircraft types not covered by standard series numbers.
zone 900
39
zone 900
Reserved for uncommon differences between aircraft types not covered by standard series numbers.
40
main structure or body of the
aircraft and carries the aircraft
payload in safe, comfortable
conditions.
fuselage
40
- major zones divided to major sub- zones(2nd digit), and major sub- zones are divided into zones(3rd
digit)
Sub-zones
41
- stresses are set up in the fuselage
of aircraft when pressurized and
tend to elongate the fuselage.
Axial Stress (longitudinal)
41
are set up in addition to axial
stress and tend to expand fuselage
cross section area.
Hoop Stress (radial)
42
hoop stress internal pressure can reach ______
65.5
kN/m2
(9.5psi).
43
putanginang prof
colocado
43
- used for light, non-pressurized, aircraft.
- It is a strong, easily constructed
and relatively trouble free basic
structure.
- covered by a lightweight aluminum
alloy or fabric skin.
Framework Or Truss Type
44
- more widely used. - all the loads are taken by the skin
with just light internal frames or
formers to give the required shape.
Monocoque Structure
45
- Materials to provide rigidity and
strength
Sandwich construction
a honeycomb core with a skin of composite material
glass fiber reinforced plastics(GFRP)
carbon fiber reinforced plastics (CFRP)
aluminumalloy
45
- Pure monocoque structure with added stringers (stiffeners)and longerons to run lengthwise along the fuselage joining the frames together.
Semi-Monocoque Construction
46
- must withstand both the loads of pressurization and impact loads from bird strikes.
- constructed from toughened glass panels attached to each side of a clear vinyl inter layer.
Flight Deck Windows
47
prevents ice from forming and makes the window more resilient and able to withstand bird strikes.
Electrically Conducting Coating
48
allow pilots to land the aircraft safely in the event of windscreen obscurity
Direct Vision Windows
49
- These are designed to be fail safeand normally have two panes of acrylic plastic mounted in an airtight rubber seal fitted into a metal window frame.
Passenger Cabin Windows
50
- support the weight of the aircraft in the air and so must have sufficient strength and stiffness.
wings
51
- Very few of this fly at more than
200 knots in level flight and so the
air loads are low.
Bi-Plane
52
- This type of design is also used on
low speed aircraft.
Braced Monoplane
53
- The mainplanes have to absorb
the stresses due to lift and drag in
flight and, if of __________ design,
their own weight when on the
ground.
Cantilever Monoplane
53
- main load bearing members.
- constructed so that they will
absorb the downwards bending
stresses when on the ground and
the upwards, rearwards and twisting
stresses when in flight.
Spars
54
- It generates direct stresses in a
span wise direction as a response to
bending moments and also reacts
against twisting (torsion)
Skin
55
- these are span wise members give
the wing rigidity by stiffening the
skin in compression.
Stringers
56
- these maintain the airfoil shape if
the wings, support the spars, stringers and skin against buckling
and pass concentrated loads.
Ribs
56
- The maximum permissible mass of an airplane with nousable fuel.
Maximum Zero Fuel Mass(MZFM)
57
- The maximum permissible airplane mass at the start of the take-off run.
Maximum Structural TakeOff Mass (MSTOM)
58
- The maximum mass of the airplane at the commencement of the taxi
Maximum Structural Taxi Mass(MSTM)
59
- The maximum permissible total airplane mass on landing in normal circumstances.
Maximum Structural Landing Mass (MSLM)
59
types of empennage
Conventional
T-tail
H-tail
V-tail
60
- provide the longitudinal and directional stability and the means of longitudinal control. - generally smaller versions of the mainplanes in that they uses pars,ribs, stringers and skin in theirconstruction.
Tail
60
- it provide Some aircraft their longitudinal stability and control.
Foreplanes (canards)
61
- provide longitudinal stability by generating upwards or downwards forces as required.
horizontal surfaces (tailplane)
62
- generate sideways forces as
required.
Vertical surfaces (fin)
63
- is the rapid and uncontrolled
oscillation of a flight control which
occurs as a result of an unbalanced
surface.
flutter
64
- Can prevent Flutter.
- alter the moment of inertia of the
surface and therefore the period of
vibration.
Mass Balancing
65
- most widely used metals for
structural use due to a good
strength to weight ratio.
Aluminum
66
- an aluminum and copper based
alloy which has poor corrosion
resistance except when clad with
pure aluminum. It also has good
thermal and electrical conductivity
and is difficult to weld.
Duralumin
67
- only used where strength is vital
and weight penalties can be
ignored
Steel
67
- is much lighter than steel and can
be used where fire protection is
required i.e. firewalls. It has good
strength and retains this and its
corrosion resistance up to temperatures of 400°C.
Titanium
68
- is designed to withstand landing at a particular aircraft weight and vertical descent velocity.
Aircraft landing gear
69
- not generally used as a structural material.
Glass fiber reinfroced plastic
69
- outperform the commonly used aircraft structural materials.
Carbon Fiber ReinforcedPlastic(CFRP) And Kevlar (KFRP)
70
- suffering fatigue retain their design strength up to a critical point after which failure occurs rapidly whereas composites lose their properties gradually.
Metal structures
71
- have good resistance to corrosion and can easily beformed into complex shapes but their fatigue behavior is different to that of conventional metal alloys and is not generally a consideration at stress cycles below approximately 80% of ultimate stress.
Composite materials
72
their principal advantage being their weight. This gives an excellent strength to weight ratio(aluminum is one and a half times heavier).
Magnesium
73
is the science relating to the behavior of liquids under various conditions and in aircraft the
_________ system provides a means of operating large and remote components that it would not be possible
to operate satisfactorily by other means.
hydraulics
74
provide a means of power
transmission through the medium of hydraulics
just like in transmission of power through an
incompressible fluid via pipelines and actuators.
Aircraft systems
74
provide the power for the
operation of components such as landing gear,
flaps, flight controls, wheel brakes, windshield
wipers, and other systems that require high
power, accurate control, and rapid response
rates.
Hydraulic systems
75
was a 17th century mathematician
who stated that: “If a force is applied to a liquid
in a confined space, then this force will be felt
equally in all directions.”
Blaise Pascal
75
“If a force is applied to a liquid
in a confined space, then this force will be felt
equally in all directions.”
PASCAL’S LAW
76
The force employed when a hydraulic system is
operated is caused by ____________
pressure
77
is created only when an
attempt is made to compress fluids, therefore, if
a flow of oil is pumped through an open-ended
tuber there will be no pressure, but, if the end of
the tube is blocked and the oil cannot escape,
pressure will at one build up
Hydraulic pressure
78
In hydraulic systems, this restriction is provided
by movable pistons which travel backwards and
forwards in cylinders, these assemblies being
known as ______________
hydraulic jacks or actuators
79
This principle was discovered by Joseph
Bramah (1749 - 1814) who invested a hydraulic
press
BRAMAH’S PRESS
80
who discovered bramah's press?
Joseph
Bramah
81
Joseph Bramah (1749 - 1814) who invested a hydraulic
press and, in doing so, observed two facts:
a. The smaller the area under load, the greater the pressure generated
b. The larger the area under pressure, the
greater will be the load available
81
This would constitute a _______________ where a force is applied to a piston
(piston A) only when it is desired to move the
load (piston B) thereby only generating pressure
when it is required rather than generating and
maintaining pressure all of the time and only
using it when something needs to be moved.
Passive Hydraulic
System
81
The efficiency of a hydraulic system is governed
by the resistance to motion encountered by the
fluid, and for all practical purposes, hydraulic
fluids are considered to be incompressible
except at high pressures, that is _______________-- and
above.
27.6 MPa
81
require lubrication to remain
effective, and wetting of the bearing surface, or
a slight seepage from the seals, is normally
acceptable.
Dynamic seals
81
perform a very important function in a
hydraulic system, in preventing leakage of fluid.
Static seals, gaskets, and packing are used in
many locations, and these affect a seal by being
squeezed between two surfaces.
Seals
82
fitted between sliding surfaces,
may be of many different shapes, depending on
their use and on the fluid pressure involved
Dynamic seals
83
is normally fitted with a stiff backing
ring, which retains the shape of the seal and
prevents it from being squeezed between the two
moving surfaces.
“O” ring
83
_________ and ________ ring seals are effective in one
direction only
“U”and “V”
83
but _________ and ______
seals are often used where pressure is applied in
either direction.
“O” rings and square section
84
Seals are easily damaged by
grit, and a ____________ is often installed on
actuators to prevent any grit that may be
deposited on the prison rod from contaminating
the seals.
wiper ring
85
; if a seal of an incorrect material
is used in a system, the sealing quality will be __________________
seriously degraded
86
replaces DTD 585 as the
British specification.
DEF STAN 91-48
87
- a phosphate ester based oil.
Used with synthetic rubber seals (Butyl). It is fire resistant and less prone to cavitation
because of its higher boiling point.
SKYDROL
87
a refined mineral based oil
(Petroleum). Used with synthetic rubber seals
(Neoprene). Recommended for all hydraulic
systems under high pressures and low or very
low temperatures
D.T.D. 585
88
If the __________ fluid is
added to a system breakdown of the seals is likely causing fluid leakage, both internally within components and externally from the
actuators.
incorrect fluid
88
A ____________ provides storage
space for the system fluid.
reservoir
89
should be handled with care as
they have a deleterious effect on skin,
paintwork, sealing compounds, rubber materials,
Perspex, etc., and they should never be mixed.
Hydraulic fluids
90
90
further increase pressure at pump inlet to reduce
possibility of cavitation
Pressurized with air from engine compressor
91
either had, engine,
or electrically driven. It
draws oil from the reservoir
and delivers a supply of fluid
to the system.
A pump
91
an ________, ____________, and ________ are used to
provide alternate supply as part of the
redundancy provisions for the safe operation of
the aircraft
air pump,
ram air turbine, and power
transfer unit
92
may be the only source of power
in a small, light aircraft hydraulic system, but
may also be used on larger aircraft
Hand Pumps
93
one example is spur gear displacement pump.
One of the gears is driven by the power source
normally used by the engine.
Constant Delivery (Fixed Volume) Pump
94
- this pump supplies fluid at a variable volume
and controls its pressure. This type of pump is
typically fitted in modern aircraft whose
systems operate at 3000 - 4000 psi.
Constant Pressure (Variable Volume) Pump
94
is
fitted to a system employing a constant
delivery (fixed volume) pump, to control
system pressure and to return to the reservoir.
Automatic Cut Out Valves (ACOV) -
95
enabling the
operator to select the
direction of the flow of
fluid to the required
service and providing a
return path for the oil
to the reservoir
A selector or control
valve
96
Used to convert fluid flow into linear or rotary motion.
A jack or set of jacks, or actuators
96
Attached to the piston is a _________ which passes through a seal and wiper ring assembly fitted into the end of the cylinder.
piston rod (or ram)
97
- hydraulically
operated in one direction only. Normally used
as a locking device, the lock being engaged by
spring pressure and released by hydraulic
pressure. This has more fluid in the cylinder
when the rod is extended.
Single Acting Actuator
97
- equal force can be
applied to both sides of the piston. It is often used in applications such as nose wheel
steering. Either one or both sides of the piston
rod may be connected to a mechanism
Double Acting Balanced
98
to keep the fluid
clean. They remove foreign
particles from the fluid.
filter
99
_____________ filter to
protect the pump
Suction filter
100
_________ filter to ensure the cleanliness of fluid
during use.
pressure filter
101
Sometimes, there is also a filter in the _______ to the reservoir to remove particles
picked up during operation.
fluid return line
102
Other filters are fitted with__________ or _____ which allows unfiltered fluid to pass to the system when the element becomes clogged.
a relief or bypass valve
103
is
maximum system
pressure that is often
controlled by adjustment
of the main engine
driven pump, but a number of other components
are used to maintain or limit fluid pressures in
various parts of the hydraulic system
Pressure Control
103
as a safety
device to relieve excess
pressure.
A relief valve
104
is when fluid is trapped
between the piston of the actuator and a
non-return valve or selector valve at its neutral
position, a “____________” is said to be formed.
Hydraulic Lock
105
The main advantage of this system is that it is simple; the main disadvantage is that only one
service can be operated at a time.
OPEN CENTER SYSTEM
106
107
Fluid is passed directly to the reservoir when no services are being operated, this allows the engine driven pump to run in an “_______________-” as little pressure is generated but there is still flow through the pump to cool and lubricate it.
offloaded condition
108
With this type of system, operating pressure is
maintained in that part of the system which
leads to the selector valves, and some method is
used to prevent overloading the pump.
CLOSED SYSTEM
108
Its great advantage is that multiple services can
be operated at the same time. Their use is only
limited by the volume flow capacity of the
pump
CLOSED SYSTEM
109
In systems which employ a fixed volume pump (constant delivery), an __________ is fitted to divert pump output to the reservoir when pressure has built up to normal operating pressure.
automatic cut-out valve
110
Stresses will tend to elongate,
compress, bend, shear, and twist
components.
ELASTIC LIMIT
111
Provided that the deformation is
within the elastic limit of the
material, the component will
return to its original dimension
once ________________
the stress has been
removed
112
Beyond the elastic limit,
deformation will be ____________-.
permanent
