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WorksheetsAirframe chap 1+2+6+9
Total questions: 104
Worksheet time: 52mins
What is the purpose of the wing main spar?
To withstand bending and torsional loads
To withstand compressive and torsional loads
To withstand compressive and shear loads
To withstand bending and shear loads
What is the purpose of wing ribs?
To withstand the fatigue stresses
To shape the wing and support the skin
To house the fuel and the landing gear
To provide local support for the skin
What is the purpose of stringers?
To absorb the torsional and compressive stresses
To produce stress risers and support the fatigue metres
To prevent buckling and bending by supporting and stiffening the skin
To support the primary control surfaces
The airframe structure must remain substantially intact after experiencing:
the design ultimate load times a 1.5 safety factor
the design limit load plus the design ultimate load
three times the safety factor
the design limit load times a 1.5 factor of safety
In the construction of airframes the primary purpose of frames or formers is to:
provide a means of attaching the stringers and skin panels
oppose hoop stresses and provide shape and form to the fuselage
form the entrance door posts
support the wings
How can wing bending moments be reduced in flight?
By using aileron 'up-float' and keeping the centresection fuel tanks full for as long as possible
By using aileron 'up-float' and using the fuel in the wings last
By having tail-mounted engines and using aileron 'down-float'
By having wing-mounted engines and using the wing fuel first
Regarding a safe life structure: 1. will only fail after a known number of operations or hours of use. 2. should not fail until a predicted number of fatigue cycles has been achieved. 3. has a programmed inspection cycle to detect and rectify faults. 4. is changed before its predicted life is reached.
1 and 2 apply
1 and 3 apply
2, 3 and 4 apply
all of the above apply
A fail-safe structure: 1. has a programmed inspection cycle to detect and rectify faults; 2. is changed before its predicted life is reached; 3. has redundant strength which will tolerate a certain amount of structural damage; 4. is secondary structure of no structural significance.
1 and 2 apply
1 and 3 apply
3 and 4 apply
all of the above apply
The skin of a modern pressurized aircraft:
is made up of light alloy steel sheets built on the monocoque principle
houses the crew and the payload
provides aerodynamic lift and prevents corrosion by keeping out adverse weather
is primary load bearing structure carrying much of the structural loads
The primary purpose of the fuselage is to:
support the wings
house the crew and payload
keep out adverse weather
provide access to the cockpit
Station numbers (Stn) and water lines (WL) are:
a means of locating airframe structure and components
passenger seat locations
runway markings for guiding the aircraft to the terminal
compass alignment markings
Flight deck windows are constructed from:
an amalgam of strengthened glass and vinyl with rubber pressure seals
strengthened glass with shock absorbing clear vinyl interlayers and rubber pressure seals
strengthened clear vinyl with an electrical conducting coat for de-icing and rubber pressure seals
strengthened glass with rubber seals
A cantilever wing:
is externally braced with either struts and/or bracing wires
is supported at one end only with no external bracing
has both an upper an lower aerofoil section
folds at the root section to ease storage in confined spaces
A torsion box:
is a structure within the fuselage to withstand compression, bending and twisting loads
is a structure formed between the wing spars, skin and ribs to resist bending and twisting loads
is a structure within the wing for housing the fuel tanks, flight controls and landing gear
is a structure designed to reduce the weight
A lightening hole in a rib:
prevents lightning strikes damaging the fuselage
provides a means of passing cables and controls through a pressure bulkhead
collects and disposes of electrical charges
lightens and stiffens the structure
Control surface flutter:
provides additional lift for take-off and landing in the event of engine failure
occurs at high angles of attack
is a destructive vibration that must be damped out within the flight envelope
is a means of predicting the critical safe life of the wing
Control surface flutter is minimized by:
reducing the moment of the critical engine
aerodynamic balance of the control cables
changing the wings before they reach their critical life
mass balance of the control surface
A damage tolerant structure:
has degree of structural strength redundancy spread over a large area
is light, non load bearing structure, damage to which will not adversely affect the aircraft
is replaced when it reaches its predicted life
need not be repaired until the aircraft undergoes deep maintenance
Aircraft structures consists mainly of:
light alloy steel sheets with copper rivets and titanium or steel materials at points requiring high strength
magnesium alloy sheets with aluminium rivets and titanium or steel at points requiring high strength
aluminium alloy sheets and rivets with titanium or steel materials at points requiring high strength
aluminium sheets and rivets with titanium or steel materials at points requiring high strength
The Maximum Zero Fuel Mass (MZFM) of an aircraft is:
the maximum permissible take-off mass of the aircraft
the maximum permissible mass of an aircraft with no usable fuel
the maximum permissible mass of an aircraft with zero payload
the maximum permissible landing mass
A force of 100 N is applied to 2 separate jacks, the area of one is 0.02 m2 and the other is 0.04 m2:
the smaller jack will exert a pressure of 2000 Pa and the larger 4000 Pa
the smaller jack will exert a pressure of 5000 Pa and the larger 2500 Pa
both jacks will move at the same speed
both have the same load
A pre charge pressure of 1000 bar of gas is shown on the accumulator gauge. The system is then pressurized to 1500 bar, so the accumulator will read:
500 bar
1000 bar
1500 bar
2500 bar
The pressure gauge of a hydraulic system provides information regarding the pressure of:
the air in the accumulator
the air and hydraulic fluid in the system
the proportional pressure in the system
the hydraulic fluid in the system
A shuttle valve:
is used to replace NRVs
allows two supply sources to operate one unit
allows one source to operate two units
acts as a non-return valve
Def. Stan 91/48 is ---------- and is ------------- based:
red, mineral
red, synthetic
green, mineral
purple, synthetic
A restrictor valve:
is used to restrict the number of services available after loss of system pressure
controls the rate of movement of a service
controls the rate of build-up of pressure in the system
controls the distance a jack moves
With a hyd lock there is:
flow, but no jack movement
no flow but jack continues to move under gravitational effects
no flow, jack is stationary
constant flow
The hydraulic fluid is changed, but the wrong fluid is replaced. This would lead to:
high operating fluid temperature
system failure from leaks and blocked filters, high temp and possible corrosion
a rise in the reservoir fill level
normal operation, it does not matter which fluid is used
Accumulator floating piston:
pushes the fluid up when being charged
pushes the fluid down when being charged
provides a seal between the gas and fluid
prevents a hydraulic lock
A relief valve:
relieves below system pressure
maintains pressure to a priority circuit
relieves at its designed pressure
prevents excessive pressure through increased fluid temperature
The primary purpose of a hydraulic reservoir is:
to compensate for leaks, displacement and expansion
to allow a space into which spare fluid may be stored
to indicate system contents
to maintain fluid between a jack and the accumulator
With air in the hydraulic system you would:
ignore it because normal operation would remove it
bleed the air out of the system
allow the accumulator to automatically adjust itself
expect it to operate faster
The pressure filter in a hydraulic system:
filters the fluid returning to the tank
is fitted down stream of the pump
can be by passed when maximum flow is required
clears the fluid as it leaves the reservoir
Pascal's law states that:
pressure is inversely proportional to load
liquid is compressible
oxygen can be used to charge the accumulators
applied force acts equally in all directions
A constant pressure hydraulic pump is governed by:
an automatic cut-out
engine RPM
a control piston
a swash plate that senses the fluid temperature
A high pressure hydraulic pump:
needs a positive fluid supply
does not need a positive fluid supply
outlet pressure is governed by centrifugal force
does not need a cooling fluid flow
Case drain filters are:
fitted to prevent debris from the reservoir reaching the system
designed to allow hydraulic pump lubricating fluid to drain to atmosphere
to enable pump lubricating fluid to be used to monitor pump condition
fitted in the reservoir outlet
The purpose of an accumulator is to:
relieve excess pressure
store fluid under pressure
store compressed gas for tyre inflation
remove air from the system
With a one way check valve (NRV):
flow stops when input pressure is greater than output pressure
flow stops when the thermal relief valve off loads the hand pump
flow starts when input pressure is less than output pressure
flow stops when input pressure is less than output pressure
A restrictor valve is physically fitted in the:
U/C up line and flap up line
U/C down line and flap up line
U/C down line and flap down line
supply line to the U/C retraction actuator
In the case of a failure of a cut-out valve:
a full flow relief valve is fitted down stream of it
a full flow relief valve is fitted upstream of it
a full flow relief valve is not required
the terminal pressure will be controlled by adjusting the pump rpm
Hydraulic pressure of 3000 Pa is applied to an actuator, the piston area of which is 0.02 m2 and the same pressure is exerted on actuator whose area is 0.04 m2:
both have the same force
both jacks will move at the same speed
the smaller jack will exert a force of 600 N and the larger 1200 N
the smaller jack will exert a force of 60 N and the larger 120 N
A separator in an accumulator:
isolates the gas from the fluid
reduces the size of the accumulator required
removes the dissolved gases from the fluid
maintains the fluid level in the reservoir
In an operating hydraulic actuator the pressure of the fluid will be:
greatest near to the actuator due to the load imposed on the jack
greatest at the opposite end to the actuator due to the load imposed on the actuator
high initially, falling as the actuator completes its travel
the same at all points
The contents of the hydraulic fluid reservoir are checked. They indicate that the reservoir is at the full level. The system is then pressurized. The contents level will:
fall below the 'full' mark
fall to a position marked 'full accs charged'
remain at the same level
rise above the 'full' mark
A pressure maintaining or priority valve:
enables ground operation of services when the engines are off
is used to ensure available pressure is directed to essential services
is used to control pressure to services requiring less than system pressure
is used to increase pressure in the system
A hydraulic lock occurs:
when the thermal RV operates
when fluid by passes a system and returns to the tank
when flow is stopped and the actuator is not able to move
when fluid and air enters the cylinder and only fluid is allowed to bypass to the reservoir
In an enclosed system pressure is felt:
more at the piston head than the rest of the cylinder
more at the cylinder end than the piston head
more when the piston is moving than when it is stationary
the same at both ends between the piston and the cylinder head
A non-return valve:
can only be fitted if provided with a by-pass selector
closes if inlet pressure exceeds outlet pressure
opens if inlet pressure equals outlet pressure
closes if inlet pressure ceases
Low gas pressure in accumulator causes:
rapid jack movements
no effect on system
rapid pressure fluctuations while system is operating
rapid and smooth operation of system
Hammering in system:
is normal and does not affect the system's efficiency
is caused by pipe diameter fluctuations
is an indication that a further selection is necessary
is detrimental to the system
The specification of hydraulic fluids, mineral, vegetable or ester based is:
always distinguishable by taste and smell
generally distinguishable by colour
generally distinguishable by colour only if they are from the same manufacturer
cannot be distinguished by colour alone
An ACOV will:
provide an idling circuit when a selection is made
extend the life of the accumulator
provide an idling circuit when the accumulator is fully charged
ensure the pump is always on load
The purpose of a hydraulic fuse is to:
allow the parking brake to remain on overnight if required
allow a reduced pressure to the wheel brake system to prevent the wheels locking
prevent over pressurizing the reservoir as altitude increases
prevent total loss of system fluid if the brake pipeline is ruptured
A shuttle valve will allow:
the accumulator to be emptied after engine shut down
the pressure pump to off load when the system pressure is reached
two independent pressure sources to operate a system/component
high pressure fluid to return to the reservoir if the Full Flow Relief Valve fails
The purpose of a reservoir is to:
compensate for temperature changes
compensate for small leaks, expansion and jack displacement
compensate for fluid loss
minimize pump cavitation
When the hydraulic system pressure is released:
reservoir air pressure will increase
reservoir fluid contents will rise if reservoir is lower than other components in the system
reservoir fluid contents will fall if reservoir is the highest point in the system
reservoir contents are dumped overboard
Hydraulic pressure in a closed system:
is greater in pipes of larger diameters
is greater in pipes of smaller diameters
does not vary with pipe diameter
varies in direct proportion to the system demands
Skydrol hydraulic fluid:
needs no special safety precautions or treatment
is flame resistant but is harmful to skin, eyes and some paints
is highly flammable and harmful to skin, eyes and some paints
is highly flammable but not harmful in any other way
Skydrol hydraulic fluid can be used to replenish:
any hydraulic system without restriction
hydraulic systems that have butyl rubber seals only
any hydraulic system in an emergency
hydraulic systems that have neoprene seals only
A variable displacement pump on system startup will be at:
minimum stroke
an optimized position depending on fluid viscosity
maximum stroke
mid stroke
The purpose of a reservoir is:
to provide a housing for the instrument transmitters
to enable the contents to be checked
to allow for fluid displacements, small leaks, thermal expansion and contents monitoring
to provide a housing for the main system pumps and so obviate the need for backing pumps
Hydraulic Thermal Relief Valves are fitted:
to release all the pressure back to return in an overheat situation
to release half the pressure back to return in an overheat situation
to relieve excess pressure back to the actuator in an overheat situation
in isolated lines only to relieve excess pressure caused by temperature rises
A main system hydraulic pump:
does not need a positive fluid supply if primed before startup
always needs a positive fluid supply in order to prevent cavitation
does not need a positive fluid supply in order to prevent cavitation
can be run dry without causing any damage
Different diameter actuators supplied with the same pressure at same rate:
exert the same force
will lift equal loads
will move at the same speed
exert different forces
A force of 1500 N is applied to a piston of area 0.002 m2 and generates a force of-----(1)------non a piston of area 0.003 m2. The pressure generated is -----(2)----- and, if the smaller piston moves 0.025 m, the work done is -----(3)------.
(1) 56.25 J (2) 750 000 Pa (3) 750 000 N
(1) 750 000 N (2) 2250 P (3) 56.25 J
(1) 225 N (2) 75 000 Pa (3) 562.5 J
(1) 2250 N (2) 750 000 Pa (3) 37.5 J
The following statements relate to hydraulic accumulators. The function of an accumulator is to: 1. Store fluid under pressure; 2. Dampen pressure fluctuations; 3. Allow for fluid expansion; 4. Replace the need for a reservoir; 5. Absorb some of the landing loads; 6. Allow for thermal expansion; 7. Prolong the period between pump cut-in and cut-out; 8. Provide the initial pressure when a selection is made and the pump is cut-out; 9. Provide an emergency reserve of pressure in the event of pump failure. Which of the following applies?
All of the statements are correct
None of the statements are correct
Statements 1, 2, 3, 4, 5, 8 and 9 are correct
Statements 1, 2, 3, 6, 7, and 9 are correct
The seal materials used with hydraulic fluids to DEF/STAN 91-48 and SKYDROL 700 specification are respectively:
natural rubber and neoprene
neoprene and natural rubber
butyl and neoprene
neoprene and butyl
To prevent cavitation of the pump a hydraulic reservoir may be:
pressurized
bootstrapped
above the pump
all of the above
A hand pump is usually fitted for:
ground servicing purposes
lowering the landing gear in an emergency
pressurizing the oleo struts in the air
retracting the gear after take-off
Oil is used in an oleo strut to:
support the weight of the aircraft
limit the speed of compression of the strut
lubricate the piston within the cylinder
limit the speed of extension and compression of the strut
The nose wheel assembly must be centred before retraction because:
there is limited space in the nose wheel bay
the aircraft may swerve on the next landing if the nose wheel is not straight
the tyres may be damaged on landing if the nose wheel is not straight
it will remove any slush or debris which may have accumulated on take-off
The movement of the gear on lowering is normally damped to:
prevent the fluid becoming aerated
counteract the force of gravity which would bring the gear down too fast
make the lowering time greater than the raising time
prevent the hydraulic fluid becoming overheated
Inadvertent retraction of the landing gear on the ground is:
not possible because the system is not powerful enough
prevented by the ground/air logic system
always a danger after the ground locks have been removed
the responsibility of the first officer when he is on the aircraft
Creep (slippage):
is not a problem with tubeless tyres
refers to the movement of the aircraft against the brakes
alignment can rip out the inflation valve on tubed tyres, and deflate the tyre
can be prevented by painting lines on the wheel and tyre
Tyre wear when taxiing can be reduced by:
restricting the use of brakes and using thrust reversers
taxiing at less than 40 kph
staying on the smoothest parts of the taxiway
taxiing at less than 25 knots
To prevent scrubbing the tyres while taxiing, you should:
use tyres with fusible plugs
make sharp turns only if you have high speed tyres fitted
turn no sharper than the minimum specified radius
deflate the tyres to a minimum pressure
The best extinguishant to use on a wheel or brake fire is:
CO2
dry powder
freon
water
When inflating a tyre fitted to an aircraft, the tyre pressure reading on the gauge should be modified by:
10 psi
10%
4 psi
4%
The most likely cause of brake fade is:
oil or grease on the brake drums
worn stators
the pilot reducing the brake pressure
the brake pads overheating
The pressure needed to operate the wheel brakes on a large aircraft comes from:
the aircraft main hydraulic system
the pilots brake pedals
a self-contained power pack
the hydraulic reservoir
Which of the following statements will produce the shortest landing run? i. Crossing the threshold at the correct height and speed; ii. Applying full anti-skid braking as quickly as possible after touchdown; iii. Using maximum pedal pressure but releasing the pressure as the wheels start to skid; iv. The use of cadence braking; v. Use of minimum braking pressure early in the landing run and maximum pressure towards the end; vi. Application of reverse thrust as early as possible in the landing run; vii. Deployment of the lift dumpers/speed brakes as early as possible in the landing run
(i), (ii), (vi), (vii)
(i), (iii), (vi), (vii)
(i), (iv), (vi), (vii)
(i), (v), (vi), (vii)
The formula which gives the minimum speed (VP) at which aquaplaning may occur is:
VP = 9 × √P where P is kg/cm2 and VP is in knots
VP = 9 × √P where P is psi and VP is in mph
VP = 9 × √P where P is psi and VP is in knots
VP = 34 × √P where P is kg/cm2 and VP is in mph
An aircraft has a tyre pressure of 225 psi, its minimum aquaplaning speed will be:
135 mph
135 knots
145 knots
145 mph
Landing gear ground locking pins are:
fitted before flight to ensure the landing gear locks are fully cocked
removed prior to flight and returned to stores
fitted after flight to maintain a hydraulic lock in the downlock jack
removed prior to flight and stowed on the aircraft where they are visible to the crew
The most likely cause of brake unit dragging is:
dirt between the rotor and stator assemblies
grease on the rotor assembly
the brake pressure being too high
incorrect operation of the adjuster assemblies
A likely cause of nose wheel shimmy is:
aircraft is overweight
the tyre pressures are too high
the aircraft is incorrectly loaded
a torque link is worn or damaged
Creep (slippage):
can damage the braking system
can be measured by painting marks on the tyre and wheel rim
may cause excess wear
never occurs on new tyres
The anti-skid system would be used:
on landing runs only
on take-off runs only
for take-off on icy runways
for both take off and landing runs
A hydraulic gear extension/retraction mechanism consists of sequence valves, uplocks and:
an anti-skid braking system
downlocks
torque links
a shock absorber
A nose wheel steering control system:
prevents the nose wheel from castoring at all times
allows the nose wheel to castor within preset limits about the neutral position
allows the nose wheel to castor freely at all times
prevents the nose gear from lowering if the nose wheels are not centralized
At an aircraft taxiing speed of 10 mph the anti-skid braking system is:
inoperative
operative
operative only on the nose wheel brakes
operative only on the main wheel brakes
The tyre pressures are checked after a long taxi to the ramp following landing. The pressures will have:
fallen by 15% from their rated value
risen by 15% from their rated value
remained constant
risen by 10% of their original weight-on-wheels value
The ply rating of a tyre:
always indicates the number of cords or plies in the tyre carcass
never indicates the number of cords or plies in the tyre carcass
indicates whether or not an inner tube should be fitted
is the index of the tyre strength
The purpose of pulley wheels in cable control systems is:
to ensure the cable tensions are equal throughout the system
to change the direction of the control cable
to ensure smooth operation of the system
to prevent the cable from slackening
The purpose of the primary stops in a control system is:
to set the range of movement of the control surface
to enable the secondary stops to be correctly spaced
to limit control movement to one direction only
to set the control surface neutral position
The purpose of the secondary stops in a control system is:
to reduce the control loads on the primary stops
to limit control surface range in the event of primary stop failure
to limit the secondary control system from excessive movement
to remove the excess backlash in the controls
The purpose of the fairleads in a cable control system is to:
alter the angle of deflection of the cables
to guide the cables on to the pulley wheels
to attach the cables to chain drives
to keep the cable straight and clear of structure
In a cable control system cables are tensioned to: 1. remove backlash from the control linkage; 2. provide tension on the turnbuckles; 3. provide positive action in both directions; 4. ensure the full range is achieved; 5. compensate for temperature variations
1, 3 and 5 only
3 only
4 only
all the above
In a cable control system the cables are mounted in pairs to: 1. remove backlash from the control linkage; 2. provide tension on the turnbuckles; 3. provide positive action in both directions; 4. ensure the full range is achieved; 5. compensate for temperature variations
1, 3 and 5 only
3 only
4 only
all the above
In a manual flying control system the control inputs to the primary control surfaces: 1. are reversible; 2. are irreversible; 3. are instinctive for the movement required; 4. are opposite for the movement required; 5. are limited in range by flight deck obstructions
1 and 4 only
2 and 4 only
1 and 3 only
1, 3 and 5 only
To yaw the aircraft to the right:
the right rudder pedal is pushed forward and the rudder moves to the left
the right rudder pedal is pushed forward and the rudder moves to the right
the left rudder pedal is pushed forward and the rudder moves to the left
the left rudder pedal is pushed forward and the rudder moves to the left
To roll the aircraft to the right:
the rudder control is moved to the right, the right aileron moves up and the left down
the aileron control is moved to the left and the right aileron moves up and the left down
the aileron control is moved to the right and the right elevator goes up and the left one down
the aileron control is moved to the right, the right aileron goes up and the left one down
The advantages of a cable control are: 1. light, very good strength to weight ratio; 2. easy to route through the aircraft; 3. less prone to impact damage; 4. takes up less volume; 5. less bolted joints
1, 2 and 4 only
3 and 5 only
1, 2 and 5 only
all the above
