11.3 Structures Aeroplanes Flashcards
What types of aircraft fuselage construction are there?
Truss
Monocoque
Semi-monocoque
What is a truss type construction?
Several members are joined together to form a rigid structure.
What is a defining characteristic of the pratt truss?
The struts only carry compressive loads while the stays only carry tension loads.
In a warren truss construction the longerons are solely connected with?
Diagonal methods
What construction do most pressurised aircraft have?
Semi-monocoque
What does the cyclic loading lead to in pressurised airframes?
Metal fatigue
What two methods are there of applying a seal to the an aircraft fuselage?
Faying
Fillet
What is a faying seal?
Two pieces of metal overlap and a bead of sealant is place in between, riveted and then smoothed.
What is a fillet seal?
When two pieces of metal are joined together.
What is the frame mate?
Where fittings or lugs are mounted for wing attatchment.
What are pylons also known as?
Spars
What force does the pylon transmit?
Thrust
How are crew seats installed?
Using quick release fasteners in tracks that are L tracks or I tracks.
How is cargo moved in and out of the aircraft?
Tracks, rollers and PDU’s
What cargo loading system components are there?
Transport
Guidance
Restraining and locking
What are transport components?
Ball mats, ball trays, roller rails.
What are guidance components?
Guide rails, side guides, centreline splitters, door guides.
What are restraining and locking components?
Cargo locks, outboard and centreline restraints and forward and end stops.
What is a ULD?
The containers used in a cargo bay.
What does ARO stand for?
Anti rollout device.
What is an anti rollout device?
Automatically lifts to prevent the ULD from coming back out.
When does the loading system receive electrical power?
When the cargo door is fully open.
What is a MED?
Main entry door
What type is a MED?
Plug type
What type are service doors?
Non-plug type.
What type are cargo doors?
Non-plug type
What is a plug door?
Designed to seal itself by utilising the pressure difference.
What are the doors on the left side of an aircraft used for?
Passenger entry.
What does the door structure house?
The opening, locking and emergency mechanisms.
What does the door structure consist of?
Frame
Beams
Formers
Intercostals
What does the door frame house?
The pressure stop fittings.
How does the door frame stop lock the door shut when the cabin is pressurised?
With a pressure stop pin
Is the pressure stop pin adjustable?
Yes
How do inflatable door seals work?
They have small holes cabin side that inflate the seal.
What are door seals made of?
Cloth and glass-fibre reinforced silicon rubber.
What are the common types of seal shapes?
Bulb
Diaphragm
Flat
Multiform
In a door latch mechanism how is the rotation of the torque tubes transmitted?
Control rods
For larger aircraft, ICAO Annex 6 Chapter 13.2.2 states: ?
Aircraft that are 500kg TOM or 60 pax shall have a locked flight deck door.
What is a CDLCU?
Cockpit door lock control unit.
What is in the bottom half of the cockpit door?
Decompression and evacuation flap
How many emergency exits are required?
Depends on the pax numbers.
Why is it important to pay attention to the cabin pressure indicators?
As they could warn the outflow valves are closed and therefore cabin pressure is still elevated.
What does a girt bar do?
Activate the door slide.
What are bar locks?
Either end of the girt bar, they lock it into the floor brackets.
What is the bulk cargo compartment for?
Non-containerised cargo such as loose luggage.
What does the door lift mechanism consist of?
Lift power unit
Gearbox
Brake assemblies
Rotary actuators
What are door prox sensors for?
Ensure they are locked for flight
What does the flight deck indicate the door statuses of?
Equipment centre access doors
PEDs
Cargo
When a passenger entry door is closed, latched, and locked, these letters (in colour) show the position of the mode select handle?
A - auto (green)
M - manual (white)
Windows, give visibility and hold pressure what do they also do?
Protect against bird impact and ice build up.
On transport aircraft what type are the windows?
Plug type, two layers.
What is the little hole for in cabin windows?
Pressure equalling.
On most modern aircraft how many flight deck windows are there?
Six
What are the two forward flight deck windows known as?
Windscreen
What is the retainer in flight deck windscreens?
Frame that attaches to the frame on the fuselage.
What types of damage are found on flight deck window?
Delam and bubbles
Chips, cracking or scratches.
How do you look for delam in windows?
Look from an angle.
What is the max allowable delam?
3.5 inches (89mm)
What are bubbles in the vinyl layer of glass a sign of?
Issue with the window heater system.
In what type of glass do v scratches rarely happen?
Chemically tempered glass.
What is the max limit for scratch depth on a windscreen?
0.0002 in or 0.051mm
What is crazing?
Small cracks that often look like white clouding.
What is in-plane cracking?
Smooth surface fissures, occurs in stretched acrylic.
What design are the majority of modern wings?
Cantilever
Wing support cables that are vertical are called what?
Jury struts
What three types of wing construction are there?
Mono-spar
Multi-spar
Box Beam
What are the principle structural members of the wing?
Spars
In a common I beam spar, what is the top and bottom called?
Caps and web.
What is a sine wave web?
A web that is curvy.
What is a false spar?
Spars that do not extend the whole length of the wing.
What are false spars often used for?
Hinge attach points for control surfaces.
What are nose or false ribs?
Ribs at the front of the wing used to shape and strengthen.
What is a butt rib?
Found inboard where the wing attaches to the fuse.
What are the three basic tank types?
Rigid removable
Flexible bladder
Integral
What aircraft use rigid removable tanks?
Light aircraft
What are rigid tanks made of?
3003 or 5052 aluminium alloy
What is terneplate?
Thin steel sheet coated with lead or tin alloy.
How were terneplate tanks construcuted?
Folded and soldered seams.
What is key about the soft flexible nature of a bladder tank?
They must remain wet.
What are aircraft with integral tanks called?
Wet wings
Where is the landing gear attachment point?
Rear spar
What is a fixed stabiliser?
Tailplane, two aerofoils that can’t move.
What is a stabilator?
One piece all moveable but no elevator
What is a variable incidence tailplane?
One piece moveable with elevators.
What forces are felt on a stabiliser?
Bending, torsion and shear.
Where are ailerons attached too?
Wing rear spar
Where are the elevators attached too?
Horizontal stab rear spar
How is the rudder attached?
To the vertical stab rear spars.
What sort of safety precautions are there when working on flight controls?
Comms
Signs
Gags
Tools
What does balancing of flight controls help with?
Eliminate flutter
What are two common methods of balancing flight controls?
Horn balancing
Mass balancing
What is horn balance?
When a section of the flying control is extended beyond the hinge.
What is mass balancing?
Adding mass to the LE of the control
What is the moment arm?
Weight x distance from hinge
What is a nacelle?
The shell around an engine.
Which part of the pylon is primary structure?
Torque box
What forces does the forward pylon attachment transmit?
Weight and lateral loads
What forces does the aft pylon attachment point transmit?
Weight and longitudinal.
What do modern nacelles feature?
Noise reduction technologies.
What are the fan cowls normally manufactured from?
Graphite-epoxy
What must a firewall do?
Prevent any hazardous quantity of liquid, gas, or flame from passing through the firewall to other parts of the aircraft.
How long should a firewall resist fire?
15 mins
What is the name of the firewall specs?
CS25.1191
What materials are considered suitable for fire walls?
Stainless steel 0.4mm
Mild steel 0.45mm
Titanium 0.45mm
What purposes do the engine mounts serve?
Connection, vibration dampening
What are engine mounts constructed from on light aircraft?
Chrome/molybdenum steel tubing
What are engine mounts constructed from on large aircraft?
Forged from chrome/nickel/molybdenum
On light aircraft how is the engine usually attached to the mount?
Dynafocal mounts
What do metal snubbers do?
Limit the excessive movement of the engine.
Where are dynafocal engine mounts angled towards?
CoG
What is the turbine vibration isolator engine mount?
Support the powerplants and isolate the aircraft structure from adverse vibration
What do the engines accommodate alongside the forces?
Thermal expansion
