AGK Systems Flashcards
The purpose of Certification Standards is to:
“Ensure an acceptable safety level for ______ and ______ as installed on the Aeroplane”
Equipment
Systems
The more catastrophic the consequences of a failure would be, the ____ ____ it must be that it can ever happen.
Less Likely
The standards for small piston engine powered aeroplanes.
CS 23
The standards for turbine powered large Aeroplanes
CS 25
Minor may be _____
Probable
Major no more frequent than
Remote
Hazardous no more frequent than
Extreamly remote
Catastrophic must be
Extremely Improbable
Failure up to 1 in 1,000
Probable
Failure of 1 in 1,000 - 100,000
Remote
Failure of 1 in 100,000 - 10 million
Extremely Remote
Failure of 1 in 10 million - 1,000 million
Extremely Improbable
____ may be Probable
Minor
____ no more frequent than Remote
Major
____ no more frequent that Extremely Remote
Hazardous
____ must be Extremely Improbable
Catastrophic
Extensive, pre-production, testing to destruction
enables a ____ ____ of a component to be established
Safe Life
A ____ ____ is then applied to all the
components so they are removed and replaced when they reach that number of cycle
Safety Factor
What 4 things can a Safe Life be measured in?
Flight Hours
Landings
Pressurization Cycles
Calendar Duration
To fail with no or minimal consequences
Fail Safe
3 Problems with Fail-safe Multiple load path
Heavier aircraft
Increased operating costs
Hard to inspect
The internal force per unit area inside a structural component as a result of external loads
Stress
The deformation caused by stress on a material, given as a change in dimension percentage of original
Strain
4 types of Stress
Tension
Compression
Torsion
Shear
The tendency of a material to return to its original shape
Elasticity
The ability of a material to permanently deform
Plasticity
Multiple load path
If one fails, Still have at least 1 back up
When ____ increases by 1%, ____ increases by 5%
Weight
Fatigue life Consumption
When weight increases by __, fatigue life consumption increases by __
1%
5%
The tendency of a member to distort when subject to compressive loads
Buckling
What 2 things can indicates buckling
Wrinkled skin
Pulled rivets
DLL Transport
2.5G
DLL Utility
4.4G
DLL Aerobatic
6G
The Ultimate Load is __ times the Limit Load
1.5
Airframes have their fatigue life calculated by the manufacture based on: (2 things)
The no. of hours flown
The no. of specified fatigue cycles
Greater mass cases greater ____
Stress
Repeated cycles of stress
Resonance
____ makes microscopic cracks in metal
Resonance
Two main types of corrosion
Oxidation
Electrolytic
Alloys must possess what 4 qualities?
Elasticity
Plasticity
Stiffness
Strength
Alloys exploit the ____ of the different ____ offered by the different materials
Benefits
Properties
Carbon Fiber Reinforced plastics (CFRP) is the
most common Reinforces plastic
Kevlar Fiber Reinforced plastics (KFRP) is
aramide
Glass Fiber Reinforced plastics (GFRP) is
Radar transparent
- Defined time limit
- ‘Failure-Preventative’ method
- Ensures items are removed from service before a
safe life expires
Hard Time Maintenance
- Inspections / functional checks
- Applied to items where their continued airworthiness
can be determined without disassembly or overhaul. - The condition of an item is monitored either
continuously or at specified periods
On-Condition Maintenance
In testing, how long must a wing withstand its ultimate load?
3 seconds
_____ is the most common method for attaching metallic structures
Riveting
_____ permit structural parts to be disassembled
Bolts
Trusses
Internal bracing frames used to prevent structure buckling
Semi-Monocoque
Series of aluminium frames joined by longerons with metal skin attached around the whole assembly
Semi-monocoque designs predominate in _____ _____
Modern aircraft
The 6 principal components of the semi-monocoque design are:
Aircraft skin Formers/frames Stringers Longerons Bulkheads Firewall
Machined or integral structures do not need _____ or other _____ _____ saving weight.
Rivets
Attachment methods
Fuselarge x-sections are circular/almost circular for 2 reasons:
Ensures that air flow will not separate at moderate angles of attack or sideslip.
More easily withstands the loads imposed by pressurisation.
The double-bubble geometry uses _____ circles, tied together by the fuselage floor, to achieve an _____ structure with less wasted space.
Intersecting
Efficient
Oval x-section fuselages benefits because of 3
reasons:
Lower manufacturing cost
Greater capacity resulting in increased revenue
Better options for cargo loading and unloading
The Pressure hull is pressurized up to
9psi
The pressure hull experiences:
Axial stress that acts along the longitudinal axis
Hoop stress that acts across the fuselage cross section
The 3 types of wing design:
The cantilever wing
The semi-cantilever wing
The externally braced wing
The _____ wing can be found on larger, faster aircraft. it has _____ support point and carries all loads _____
Cantilever
One
Internally
The _____ wing has some supporting external struts
Semi-cantilever
An _____ wing has external supporting struts and bracing wires
Externally braced
The torsion box is very _____, resistant to _____ and greatly adds to wing _____.
Ridgid
Twisting
Strength
Wing ribs do what 2 things:
Provide aerodynamic shape
Allow the stressed skin to be attached to the wing structure and transfer the loads into the spar
Stringers combine with ribs to share _____ and transfer load to _____
Loads
Spars
_____ _____ provides the smooth _____ outer cover and withstands _____ and _____ stresses
Stressed Skin
aerodynamic
Tension
Compression
Wet wing is
Internal wing spaces that can form an integral fuel tank
Cargo doors are usually hinged along their _____ _____ and open directly _____ and _____. These hatches are held in place by _____ hook locks.
Top edge
Outwards
Upwards
Overcenter
Flight deck windows must be able to do 5 things:
Have excellent optical qualities Withstand cabin pressurization forces Withstand stresses imposed by temp. difference Withstand significant impacts Be able to de-ice
Windscreen panels are made of 5 things:
Two or more transparent plies
Strengthened glass
Clear-Vinyl Vinyl Interlayer (absorbs impact loads)
An Electrical Conducting coat for Anti-Icing
The Window set in Rubber Pressure-Seals
CS 25 requires aircraft equipped with direct vision window to _____ _____ or _____ _____. And it must be _____ to be used as an _____ _____
Slide back
Open inwards
Large
Emergency exit
CS 25 says an Aircraft and Windscreen must be able to continue a safe-flight and landing after:
An impact by a 4Ib (2kg) bird at Vc Sea level or 0.85 Vc at 8,000ft.
On light aircraft, the majority of the floor is made up of…
The wing section extending through the cabin
Doors and hatches provide 5 things:
Normal access points (passengers and crew)
Emergency egress points
Large access points (Cargo)
Service access points (allow cabin service equipment to get to the galleys)
Access points to areas required for routine servicing
On small un-pressurized aircraft, doors are usually hinged on their _____ _____
Forward edge
A slightly open door will…
Significantly increase drag
Large aircraft doors have a series of _____ _____ and _____.
Locking pins
Latches
Most large transport aircraft use a ____ ____ design for normal access points.
Plug door
When plug doors are set in place in its frame, it is ____ for the door to open _____.
Impossible
Outwards
A plug door has two important implications:
Doors must initially open inwards to the cabin
It is impossible for a human to open the door when the cabin is pressurized.
Smaller passenger aircraft have doors that incorporate _____ _____. These doors open outwards using a conventional _____ type hinge.
Air Stairs
Piano
Some over wing exits swing __ and _____ and are held closed by _____.
Up
Outwards
Locks
CS 25 requires aircraft to be fitted with a _____ _____ _____ to ensure pilots set their eye position to the correct point
Eye reference position
Passenger windows are made of an _____ _____ and comprise of an _____ _____ and _____ pane
Acrylic material
Outer
Middle
Inner
The system is _____ _____ becuse either the outer or middle pane can withstand the _____ _____ _____ load
Fail safe
Full cabin pressurization
Hydraulic systems transmit _____ to remote locations
Power
Force in a hydraulic pressure system is the
input/output expressed in Ibs
Hydraulic fluid must:
low viscosity Resistant to foaming/crating sludge good lubrication Corrosion resistant High boiling point and low freezing point Chemically inert non flammable good storage properties
A closed center system provides
Constant pressure
An open center system provides
Pressure only when needed
Active hydraulic pumps use _____ or more _____
One
Pumps
Hydraulic fluid is available in 2 forms:
Synthetic
Mineral
It is important that 2 different type of fluid is not mixed because it can destroy _____ and _____ components
Seals
Corrode
Advantages of hydraulic systems
Can provide large amounts of force to operate heavy services
Leaks are easy to spot
Reduced weight compared to a mechanical system
Disadvantages of hydraulic systems
Fluid is highly corrosive
Forces generated require strong structures
Susceptible to fluid contamination
Exposure to Hydraulic fluid with out PPE is a health risk.
Hydraulic fluid is environmentally hazardous.
Hydraulic systems drive an _____ which is the main leverage unit, this houses a _____
Actuator
Piston
A _____ _____ diverts hydraulic pressure to the appropriate side of the _____
Selector valve
Actuator
A _____ stores excess Hydraulic fluid.
Reservoir
A ___ prevents reverse flow through the _____
NRV (non-return valve)
System
A _____ pressurizes the fluid flow
Pump
An _____ stores hydaulic fluid under pressure, and provides an _____ supply of _____ in the event of a pump failure.
Accumulator
Emergency
Pressure
A _____ prevents foreign matter being passed into the system
Filter
A ___ dumps excessive system pressure back to the reservoir.
PRV (Pressure relief valve)
The 3 types of actuator:
Single acting
Double acting balanced
Double acting unbalanced
A __________ actuator uses hydraulic pressure to move the piston in one direction only. A _____ supply’s the return force.
Single acting
Spring
In a __________ actuator, hydraulic pressure moves the piston in both direction.
Double acting balanced
The __________ actuator has inlet ports that are acting on both sides of the piston face.
Double acting unbalanced
Non return valves allow _____ to flow in _____ direction only.
Fluid
One
A _____ hydraulic system has no hydraulic pump, instead, all power must be supplyed by the _____.
Passive
Pilot
An _____ hydraulic system uses one or more hydraulic pumps.
Active
The _____ _____ system is used on small to mid-sized aircraft that don’t have large amounts of hydraulic power available .
Open Center
The _____ _____ system maintains a constant supply of hydraulic pressure using a _____ _____ pump
Closed center
Variable volume
The reservoir normally provides fluid through a _____ _____.
Stack pipe
Inside the reservoir, there is an _____ _____ which ensures there is some fluid available in the case of a major fluid loss
Emergency supply.
_____ and _____ inside the reservoir reduce the fluid swirling due to the aircraft maneuvering.
Fins
Baffles
A pressurised reservoir prevent the fluid from _____ at altitude and provides _____ at the inlet to the engine driven pumps which helps to prevent _____.
Boiling
Pressure
Cavitation
Accumulators are comprised of pressurised _____ and _____ in a cylinder separated by a piston or rubber diaphragm.
Gas
Fluid
When the pumps are running and the system is operating, _____ pressure = _____ pressure.
Gas
Hydraulic
Accumulators are often used in the _____ system to provide up to _ applications of brake.
Braking
_
A pressure gauge displays:
The pre-charge nitrogen gas pressure when the hydraulic system isn’t powered
The hydraulic system pressure when it is.
Incorrect pre-charge pressure causes
Harmful Hammering
Excessive pre-charge pressure causes
Insufficient fluid to be stored in the accumulator.
Very low pre-charge pressure results in
insufficient fluid pressure in the event of pump failure.
4 Types of engine driven pump
HYDRAT (Ram air turbine)
PTU (power transfer unit)
Hand operated
Electrical
A _____ _____ provides a constant fluid supply
Constant delivery (Fixed volume pump)
An _____ ___ ___ _____ is normally fitted in conjunction with a constant volume pump to regulate hydraulic system pressure.
Automatic cut out valve (ACOV)
A constant pressure pump comprises of a series of _____ attached to a _____ _____ which is rotated by a _____ _____.
Pistons
Swash plate
Drive shaft
A _____ _____ adjusts the angle of the swash plate and therefore the output from the pump.
Control piston
A _____ _____ uses hydraulic pressure to generate rotary motion
Hydraulic motor (rotary actuator)
A ____ ____ ____ ____ is a valve which is capable of relieving the equivalent of the total pump output.
Full flow relief valve (FFRV)
A ____ ____ reduces fluid flow to slow the speed of operation of a service.
Restrictor Valve (choke valve)
The _____ _____ ensures sufficient fluid flow at all times to the primary controls wand wheel brakes.
Priority valve
The _____ _____ allows one service to be operated by two independent supplies thus guaranteeing an adequate supply if either system fails.
Shuttle valve
_____ _____ are fitted upstream of components to shut off flow and prevent total fluid loss in the event of a major leak.
Hydraulic fuses
_____ _____ are similar to fuses in that they can shut-off services, however the valve isn’t self regulating but operated by an external controller.
Shut-off valve
Large aircraft hydraulic systems must meet 6 requirements:
Redundancy through the use of duplicated systems
Instant response to inputs
The ability to operate multiple services simultaneously
Prioritised supplies to the flight controls and wheel breaks
Emergency sources of pressure
Greater output to overcome the much heavier operating loads
The RAT can be an ______ _____ or a _____ _____ and provides the bear minimum _____
Electrical generator
Hydraulic pump
Pressure
The RAT is slightly bigger than a _____ ______
Jack Russell
The _____ _____ _____ contect multiple hydraulic systems so if one fails, it can drive the hydraulic pump in the failed system
Power transfer unit (PTU)
The Tricycle landing gear comprises of…
2(or more) main gear
1 nose gear
The Tail wheel system comprises of…..
2 main gear
1 tail dragger
The legs attach to the fuselage from the wheel.
Cantilever spring
Landing forces absorbed by a rubber bungee
Rubber bungee
A shock absorber absorbs landing shock
Oleo pneumatic struct
Main gear with more than 2 wheels…
Bogeys
The rate at which the oleo strut can compress is limited by the _____ with which oil can _____ through the orifice.
Speed
Flow
The oleo strut normally contains ____ oil and _____ gas.
Hydraulic
Nitrogen
The oleo strut uses gas _____ to support the aircraft’s weight at _____ and to act as a ____ to absorb landing and taxi loads
Pressure
Rest
Spring
The oleo strut uses hydraulic oil to control the rate of _____ and _____ or recoil of the leg through a _____ device in the leg assembly.
Compression
Extension
Metering
Wheel axles
the shaft that allows the wheels to rotate freely
Drag strut
Braces the landing gear leg against the shock loads
Lateral side stay
Withstands side loads due to crosswind.
4 requirements of the nose wheel:
Free castoring (steering system)
Automatic self-centering using springs or centering cams
Shimmy protection
The ability to withstand high loads/
Down-locks ensure that
accidental retraction cannot occur on the ground
Up-locks are a type of _____ _____ which require hydraulic pressure to _____ and _____ them.
Hook lock
Engage
Release
Ground locks usually come in the form of a _____ which fits into the ___________
Pin
Landing gear leg assembly
No lights in the cockpit means
The gear is up and locked.
3 systems for emergency gear lowing:
Manual hand crank
Compressed nitrogen to blow the gear down
Gravity/free fall system
The 2 forms of steering available for light aircraft:
Differential braking
Rudder peddle steering
You can steer large aircraft using a _____. which can steer the nose wheel up to ___.
Tiller
75°
Shimmy can be caused by 3 things:
Worn/broken torque links
Wear in wheel bearings
Low/uneven type pressure.
Shimmy can be prevented by 5 things:
Hydraulically locking the steering system
Hydraulic dampers
Self centering springs
double nose wheels
Marstrand wheels (wheels with 2 points of contact)
Well based wheels are usually fitted to _____ ______ and have _____ _____
Light aircraft
Tubed tyres
Detachable flange hubs allow easy _____ ______
Tyre replacement
Aircraft tyres comprise a _____ _____ which is constructed if _______ coated rayon, cotton or nylon ply cords. These are wrapped around _____ at each edge of the tyre.
Flexible casing
Rubber
Beads
The core of the ______ is a series of _____ wires which reinforce the tyre and hold its shape.
Bead
Steel
Tyres are inflated with _____ which helps absorb _____ upon landing.
Nitrogen
Shocks
Holds the tread patter and makes contact with the surface.
The crown
Where the tyre starts to thin from the crown
The shoulder
The weakest part of the tyre
The sidewall
The strong rim of the tyre
The bead
Tyre hubs are made from _____ _____
Aluminum alloys
Ply rating
An indication of the tyres strength
Tyre slipping around the wheel upon landing
Tyre Creep
Creep mark size for tyres <24in in diameter
1 inch
Creep mark size for tyres >24in in diameter
1.5 inches
Creep is most likely to occur after ______ ______ _____
Newly fitted tyres
Most common tyre for aircraft using concrete or tarmac runways
Ribbed tyres
Tyres used for rough/unmade runway strips
blocked tyres
Tyres with two areas of contact with the ground.
Marstrand
Tyre that deflects water spray away
Chined Tyre
The minimum tread for a tyre is ___
2mm
except blocked tyres where as long as pattern is visible it is accepted
When inspecting a tyre you should look out for:
Cuts Bulges Foreign object damage Contamination Creep Wear Pressure
Aquaplaning
where water lifts the tyre off the ground
Equation for minimum aquaplaning speed for a rotating tyre:
9 x √tyre pressure (psi)
or
34 x √tyre pressure (kg/cm²)
Equation for minimum aquaplaning speed for a non-rotating tyre:
7.7 x √tyre pressure (psi)
To prevent tyres exploding due to excessive heat, a _____ _____ is fitted which blows before a tyre reaches excessive _____. This is protected from melting by the breaks by a _____ _____
Fusible plug
Pressure
Heat shield
There are two types of disk breaks:
Fixed disk - floating caliper
Floating disk - fixed caliper
The breaks are made from _____
Carbon
Larger aircraft use multiple __________ system breaks
Floating disk - fixed caliper
Aircraft are fitted with ___________ to check the break wear.
Break wear indication pins.
On a multi disc system a series of pads are arranged around both sides of a _____ _____
Stator assembly
In between each pair of _____ is a _____ _____, which is engaged with the wheel assembly via the _____ _____
Stators
Rotor segment
Torque tube
A _____ _____ carries the operating pistons
Torque plate
4 Benefits of a carbon braking system:
Weight
Performance
Durability
Economy
An anti-skid system works by
Monitoring wheel rotation and applies and releases breaks is a wheel is slowing down too quickly.
Touch down and bounce protection features stop
break pressure being applied before thew aircraft is in solid contact with the ground.
Locked wheel skid control is deactivated at _____
15-20kts
Normal skid control is deactivated at _____
8-12kts
To disarm auto-breaking you can:
Press the break pedals
Increase the throttle
Fail safes for breaks:
2+ hydraulic systems going to them
Accumulators in the hydraulic systems.
The parking break will
Override all other systems
When chocks are placed under the tyres, you can…
Release the parking breaks to let them air cool.
Controls thew Yaw
The Rudder
Controls the Pitch
The Elevator
Controls the Roll
The Aileron
3 means of operating flight control surfaces:
Manual
Partially powered
Fully powered
5 Benefits of the manual control systems are:
Cheap Simple Reliable Does not need power to operate Aerodynamic feel helps not over-stress the aircraft
In a Manual control system, _____ _____ run from each control via a _____ _____
Steel cables
Pulley wheels.
The controls on the manual control are _____
Reversible
What is the turn buckle’s job?
To tension the cables
Moment = _____ x _____
Force x distance
Hinge moment = __________ x _____
distance form the hinge x force felt
Setback hinge
The hinge is moved further back along the elevator so the distance is reduced.
Balance seal
Flexible material between the elevator and the wing helps to push the elevator up/down
Balance tab
a smaller elevator on the end of the elevator aids pushing the main elevator up/down
Anti-balance tab
The opposite of a balance tab, used when the control system is too easy to move to help stop the aircraft over-steering
Trim tab
Adjusts the tab on the end of the elevator to make the control system easier to handle for S&L flight
