11.3 Flashcards
What is the two type of truss fuselage
Pratt and Warren
What’s a truss type
A form of construction in which multiple members are joined to form a rigid structure
What type of sealant is used to assemble the ac fuselage
A two part polysulfide sealant
What reasons can sealants be used in ac
Prevent corrosion
Prevent leaks
Give aerodynamic surface
Why are external window fairings that come into contact with the fuselage sealed
Weather protection
What are the two types of seals
Faying
Filet
What does the sealant between the two surfaces in a Faying seal provide
Pressurisation seal
When’s a filet seal used
When two metal pieces are being joined together
Why do electrical and control cables need to be sealed
As they pass through many pressure bulkheads and want to prevent leaking but the seals shouldn’t be to tight as it may affect the ability of the control cable to move
Why are strong frames in the fuselage required at the point where the wing attatches
As they help to distribute the load to the rest of fuselage
What’s the difference between the attatchment of the vertical stab to the horiz stab
The horiz stab sometimes doesn’t require any extra attatchment a as it’s built into frame alr
Vertical has to be attatched to framing or bulkhead
What’s transfers the thrust from the engine to the framework
Pylons
What are the attachment points for the chairs called
L or I tracks
What moves the cargo in the cargo bay
Pdu assisted by rollers
What’s a ULD
Unit loading device
What’s an ARO and when will it operate
Anti roll out device
Operate when hit by a ULD baseplate from outboard
What’s important about the ARO when shutting the cargo door
Must be retracted before the doors closed
How are ac doors numbered
From front to back
1 first
What type of doors are main doors, cargo, service
Main- plug
Cargo and service- non plug
How does a plug type door work
It works by using the differential pressure from the cabin air pressure to hold the door shut until the aircraft is depressurised
What way are non plug doors designed to be opened and what door does this not suit
Inwards
Cargo doors
What are the left hand doors used for and the right hand doors
Left hand- passenger entry
Right hand- galley servicing
What part of the door gives its rigidity
Intercostals
What do door frame stops do
Hold door closed when doors closed and cabin is pressurised
Uses a pressure stop pin to adjust the door to its correct position
What are functions of door seals
Prevent air pressure leaks
Prevent temp leaks
Prevent noise leaks prevent light leaks
Prevent light leaks
Improve aerodynamic smorthness
What are door seals made of
Cloth and glass reinforced sill icon rubber
What type of seal does the flap type seal provide
Pressure and weather
What does ICAO Annex 6 chapter 13.2.2 state about flight deck doors
All passenger with a certified max take off mass of 45,500 kg or passenger seating is more than 60 than an approved flight crew compartment door that is designed to resist penetration by small arms fire and grenade shrapnel, and to resist forcible intrusions by unauthorised persons
What two characteristics should small passenger ac cockpit doors have
Should be resistant to penetration when closed
Acces should only be if the door is opened normally
What materials are used in the construction of COCKPIT doors
Kevlar and dyneema
Glass reinforced polymers
Laminated of high strength S-2 glass fibres
What’s contained in the lower part of the flight deck door
Decompression and evacuation flap
What type of doors are over wing emergency exits
Plug
What’s important for the door operator to check before opening the door in an emergency
That the cabin pressure warning light isn’t on
What controls the girt bar position
The mode selector lever
Where’s the bulk cargo door located
Aft lower right hand side of fuselage behind aft cargo door
How are cargo door operated
Hydraulically electrically (manual if not available
If the bulk cargo door fails to stay open
Th counterbalance spring should be checked for the correct tension
How are passenger windows constructed
Plug type windows made of acrylic plastic
How many panes are there of plastic in passenger window
2
Sometimes a 3rd in middle for noise
Why’s there a hole in the inner pane of acrylic glass on passenger Windows
To ensure the pressure in between the panes is equal and that the window doesn’t mist
What’s used to clean Windows
Isopropanol or soapy water
Ow many flight deck windows are there usually
6
How are Windows numbered
1L 2L
1 R 2R
What’s cockpit windows made of
Tempered glass and plastic
What’s the outer pane made off in a cockpit window
Glass
How are cockpit windows heated
They have a conduction layer in the window build up which electrically heats up
What’s between the glass panes in a cockpit window construction to seal it
Silicone
How are cockpit fixed windows installed (internal or external)
Externally
What two types of damage on flight deck windows
Delamination and bubbles
Chips cracking or scratches
Where on the window does Delamination commonly occur
Edges
What depth does a scratch have to be for the window to have to be replaced
Scratches more than 0.002 inch in depth
What’s crazing
Small fissures which frequently start from small scratches in window face
What’s a crack ( windows )
A fissure where one can see the width when one looks along the faces of the fissure
What is the majority of ac wings design
Cantilever
What are the wing fairings purpose
To reduce drag
What’s the most common material used in wing construction
Alluminium
What’s the primary structural element of the wing
Spars
Where does the stress from the skin on the wing get transferred to
Ribs and then they transfer to the spars
What’s the difference between a mono spar, multi spar and box beam wing construction
Mono- only one main longitudinal member in its construction
Multi- more than one main longitudinal member
Box- two longitudinal members and connecting bulkheads for extra strength and contour to the wing
What’s the most common spar used in wi gs
i-type ( top and bottom are called caps and the middle is called the web )
What’s the difference between false spars and normal spars
False spars don’t run across the whole length
Why are wingtips usually removable
Prone to damage
What structure are the wing tank stress skin panels made of
Honeycomb
What where early rigid removable feul tanks made off
Thin sheet of steel, coated with Tin or lead alloy
CALLLED TERNEPLATE
What’s added to secure removable fuel tanks in flight
Padded straps to prevent movement and chafing
What’s a bladder tank made off
Reinforced flexible material
What’s a benefit of bladder tanks
They don’t require such a large opening in the skin to install
What’s important to remember when installing a bladder feul tank
Bottom must not be wrinkled
What’s done to a bladder tank when it’s being stored for a long period of time
It’s coated with clean engine oil to prevent cracking and drying
How’ are integral wing tanks made
By sealing the wings with a fuel resistant two part sealant to form a fuel tank
What’s a benefit of a integral tank
allows maximum volume of fuel at lowest weight
What are aircraft with integral wing fuel tanks called
Wet wings
What’s used to allow the fuel to move to the low in board parts of the integral feul tank
Baffles use check valves to move it there but prevent it from going back
What are the wing tank access pannels sealed with and why
O ring and gasket for electrostatic bonding
What part of the wing is the landing gear attatched to
Rear or false spar usually
Spars have to be very strong as the support weight of aircraft during flight
Is the pylon built forward or aft of the forward wing spar
Fwd
Where’s the loads from the control surfaces transferred to
Wing structure
What spar and face of the spar is the spoilers, ailerons, flaps and slats
Slats- Fwd face of the front spar
Flaps- lower edge of rear spar
Ailerons- trailing edge wing structure
Spoilers- aft space of rear spar
What’s another name for a fixed stabiliser
Tailplane
How are the attatchment points of the vertical stabiliser strengthened to the fuselage
Splice, plates and stiffeners
What does balancing of a flight control help to ensure
Remove flutter
How doses the size or speed of the aircraft affect the force requires to move control surfaces
Higher the speed and heavier the aircraft the more force required
Why are control surfaces aerodynamically balanced
To reduce the forces required to deflect the control surface
What’s aerodynamic horn balancing
When a portion of the control surface of the ac is extended out ahead of the hinge line to assist in deflecting the control surface
Whats mass balancing
Accomplished by adding weights to the leading edge of the control which moves he c of g of the flight control forward and makes the bit behind the hinge line as light as possible
What type of structure is an engine pylon torque box
Primary
How many attatchment points do3 the engine pylon torque box have to the wing
3
2 fore
1 aft
What does the engine pylon torque box house
Bearing and engine attachment fitting
What loads does the fore pylon attachment take
What loads does the aft pylon attachment take
Fore- weight and lateral loads
Aft- weight and longitudinal
Where does the fore pylon bolts attatch to
Aft pylon bolts attach to?
Two fitting on the wing front spar
Attached towing Beam
What do modern engines use to reduce noise
Acoustic panels
What materials are usually made to make the nacelles outer skin
Magnesium alloy and aluminium
In hot areas stainless steel or titanium alloy
What’s the role of the fan cowl support beam
Supports the fan cowl and distributes the loads through the beam to the torque
What’s the fan cowls usually made of
Graphite epoxy structures
How long do regulations say that the firewall should be able to resist fire penetration
15 mins
What does the current specification state that each firewall should be
Fireproof
No liquid , gas’s or flame should be Abel to pass through the fire wall or shroud to other parts of the ac
Each opening in the Firewall should be fitted with a close fitting, fireproof grommets, bushings and firewalls fittings
Protected against corrosion
What type of heat resistant materials are firewalls made of
Stainless steel, iconel and titanium
When inspecting a firewall where should close attention Be payed to
Near engine mounts, near holes where control cables or electrical cables move through the firewall
What are engine mounts made of
Chrome, molybdenum steel and nickel
What are the bracing memeners in engine mounts called
V struts
How are engine mounts secured to the aircraft
Heat treated steel bolts
What load does the upper engine mount take
Weight and torsion (affects all not just top)
How many attachment points are there usually on the engine mount structure
4
What’s type of mounts are using to attatch the engines
Dynafocal mounts
What’s used to minimise engine vibration
Shock mounts made of rubber and steel
What limits excessive movement movement is the engine is subjected to abnormal shocks or loads
Metal snubbers
What kind of support do dynafocal mounts give and how
Directional support by angling the mounts to point the c of g
How many engine mounts support turbofan engines
2 fore
1 aft
What loads do the fwd and aft vibration isolation engine mounts take
Fwd - Vertical, side, axial loads and permit thermal expansion
Aft - vertical and side
What causes the humidity of the air to drop after its recycles and why
What’s done to resolve this
It’s repeated cycles through the water separators
Humidifiers
What altitude are cabins designed to be at
8,000ft
At what cabin altitude are flight crew required to be on oxygen
Passengers?
Crew- 10kft
Pass- 15ft
At what cabin altitude are flight crew required to be on oxygen
Passengers?
Crew- 10kft
Pass- 15ft
At what cabin altitude are flight crew required to be on oxygen
Passengers?
Crew- 10kft
Pass- 15ft
What’s atmosphere pressure also known as
Barometric pressure or inches of mercury
At fifty thousand feet what fraction of pressure is in the atmosphere compare to sea level
One tenth
What’s the distance between the troposphere and earths surface
38,000ft
What’s the rate of change in temp for every 10000 ft In troposphere
-2 or -3
What’s the rate of change in temp for every 1000 ft In troposphere
-2 or -3.5
What’s the relative constant temp of the tropopause
-57 c
Why’s there less drag at high altitude
Less air density
How’s Cabin differential pressure calculated
Cabin pressure - ambient pressure
What’s the normal climb rate per minute
500ft
What’s the normal descending rate per minute
300ft
What are the three modes of pressurisation
Isobaric- one single pressures selected and maintained
Differential - works to maintain a a constant pressure difference between the air pressure between the cabin and the outside pressure
Manual- allows isobaric control and the rate of it to be turned off when faulty
How longs it take to get to 40,000ft
20 mins
What controls the operation of the outflow valve
Pressure controller
How do outflow valves door operate
Pneumatically
When will positive safety valves open
When there’s a differential pressure is between 8-10 psi
What pressure differential will cause negative safety valves to open
0.5-1 psi
Open inwards
When are dump valves used
Abnormal or emergency situations
What 3 flight deck indications are there that
What are the three cockpit indications of a pressurisation defect
Cabin altimeter
Cabin rate of climb or vertical speed indicator
Cabin differential pressure indicator
How many motors operate the outflow valves and what type of motor is it
2 AC
1 for back up
What mode is selected when the ac is being taxii’d
Why
What psi
Flight
So there is no sudden surges of pressure and it’s gradual
0.1pai
