Module 11.3 Aeroplane structures Flashcards
What are two types of truss-type fuselage?
- Pratt
- Warren
What are the similarities between the two types of truss construction?
- Longerons
- Vertical struts
What load can the diagonal stays take on a Pratt truss-type fuselage and why?
Tension only as they are wires
What loads can warren type diagonal members take?
Compression and tension
Where are loads carried in a stressed skin fuselage?
In the exterior skin
What is sealant used for?
To provide leak free seals at joints
What are the two methods of sealing?
Faying and fillet
When would a faying seal be used?
Two overlapping surfaces i.e. Joggle joint
When would a fillet seal be used?
Two joined pieces of metal i.e. stringer to skin
How is pressure retained when cables and electrical wires pass through pressure bulkheads?
Grease filled pressure seal
What are the fuselage attachments?
- Wings
- Pylons
- Stabilisers
- Landing gear
What can be done to the fuselage to accept a centre wing box?
Notched or cut
Where are lugs mounted on the wing?
Forward and aft wing spar
How is the vertical fin attached?
Lugs/ bolt fittings on a frame member
Where are the fittings on the stabiliser?
In line with the front and rear spar
What transfers the thrust load from the engine to the wing in the pylon?
Upper, middle and lower spar
What is the streamlined enclosure that a pylon is attached to called?
Nacelle
Where are the lugs for engine to pylon and pylon to wing?
Forward and aft
Where is the landing gear attached?
Wing spar/ framework of spar
What can form the forward and aft wall of wheel wells?
Bulkheads
What do seat tracks allow for?
Easy removal of the seats and a secure attachment
Why are ball mats used at the entrance of the cargo hold?
To allow for manoeuvring of the cargo during unloading and loading
What are the 3 components needed in the cargo loading system? (Not part names)
- Transport
- Guidance
- Restraining and locking
What can move the cargo over the cargo hold floor?
PDU’s, Power Drive Units
What are some transport components in the cargo bay?
PDU’s and ball mat
What is the purpose of an ARO? (Cargo bay)
Anti-Roll-Out prevents the ULD from moving/falling out
Where are ARO’s found?
Cargo door sill
If switch is on and aircraft power is on what condition must be met for loading system to work?
Cargo door must be fully open
What doors are used for loading, unloading and emergency exit?
Main Entry Doors (MED’s)
What do service doors allow?
Access to systems for servicing
How does a plug type door seal itself?
Seals itself by taking advantage of the differences in pressure. The high pressure wedges the door into the frame
How does a non plug type door seal itself?
Opens outward and locks with pins or latches
What type of doors are cargo and service doors?
Non-plug type
How are MED’s numbered?
From nose to tail, followed by letters corresponding to the side of the aircraft
How is the crew notified that the door is latched correctly?
Door warning system
What is the aircraft door structure similar too?
The fuselage
What is skinned on the inside and outside of the door for strength?
Vertical and horizontal aluminium structural members
What does the door structure consist of?
- Beams main structure in frame
- Formers connect parts or attach brackets
- Intercostals provide additional rigidity
What does the door frame stop do?
Holds the door closed when pressurised using a pressure stop pin
What transfers the pressure loads to fuselage fittings?
Pressure stop fitting
What are the functions of door seals?
- Stop leaks and light
- Reduce noise and thermal
- Improve streamlining
When do some seals inflate?
When the aircraft is pressurised
What are the locking mechanisms controlled by? (Doors)
Interior and exterior handles
If a MED is to be opened from the inside, what precaution must be taken before hand?
Ensure the door is disarmed
The operator should ensure what light is not lit before opening a MED?
That the cabin pressure light is not lit
What are some requirements for the flight deck door?
- Lockable
- Bulletproof etc.
- Decompression panel
What should occur in the event of cockpit decompression?
Door opens if not the panel will
Where are emergency exit hatches located?
Over the wing
What holds the emergency slide to the aircraft?
Girt bar
What will happen if someone attempts to open a door that is still armed?
A Light will illuminate warning the person that the door is still armed. This is only an issue if the door is opened from the inside.
What should be installed on the cargo door actuators to stop them from closing?
Safety gags
What can be installed to ensure the MED is in the disarmed position?
Safety pins
What are cargo doors connected to?
Fuselage frames
Where is the bulk cargo door?
Behind the aft cargo door on the right
How is the bulk cargo door opened?
Manually
What assists in the opening of the bulk cargo door?
Counterbalance spring
What are passenger windows attached to?
Frames that are part of the fuselage
What is the composition of a passenger window?
Outer pane into the frame with a retaining device. Followed by a seal and the inner pane
What windows are in the flight deck?
3 on each side. Centre is the windshield, middle is the moveable and the furthest back is a fixed window
How is the glass in the cockpit constructed?
Laminated with sealant in-between.
What is the anti-ice protection of a window?
Conductive lamination to defrost/ de-mist
What additional benefit does the heating element have for the window?
Increase impact resistance
Chips, Cracks and scratches should lead to window replacement under what conditions?
- Chips, Cracks in inner pane
- Cracks in the outer glass
- Cracks in the vinyl
- Scratches more than 0.002 inches deep
What does a full cantilever design mean?
The weight of the wings is fully supported by the fuselage with no braces
What are jury struts?
Struts that run vertical
What is the wing construction based on?
Mono-spar, multi-spar and box beam
Wing tips are for what purpose?
Round off wing and have the Nav light
What can be done to ensure safety while working on primary control surfaces?
Control locks
What are methods of balancing?
- Aerodynamic (Horn)
- Mass balancing
What is the function of a pylon?
To carry the engine
Where is the aileron attached to the wing tips?
The front spar of the aileron is attached to the rear spar of the wing
Where are the outboard set of spoilers located?
Aft face of the wing rear spar
Where are the inboard set of spoilers located?
Aft face of the spoilers support beam
What are both the inboard flaps attached to?
Spoiler support beam and landing gear support beam
What are both the outboard flaps attached to?
Lower edges of special wing ribs, forward of the wing rear spar
Where are the actuators for LE flaps and slats?
Forward face of the wing front spar
How is the vertical fin accessed?
Removable access door bolted to the inside of the fuselage
What are the control surface attachment types?
Hinges or tracks
What does the torque box house?
Bearing and engine attachments fittings
Where is the fan cowl support beam?
Extends forward of the torque box and is bolted by a link and attachment fittings to the forward end of the torque box
When the aircraft is airborne, what stress affects the engine mount bolts?
Torsional
When the aircraft is on the ground, what engine mount bolts take the weight of the engine?
Top bolts
What forces does the forward engine mount take?
- Vertical, side and axial
What can both the aft and forward turbofan engine mount accommodate for?
Thermal expansion
What forces can the aft engine mount take?
- Vertical and side loads
What type of engine would an engine mount ring be found?
Reciprocating
What are the mounts on a reciprocating engine called?
Dynafocal mounts
What is the purpose of dynafocal mounts?
Isolate vibration from engine
How are powerplants divided into cooling zones?
Fireproof bulkheads, known as firewalls
What must fire shields and heat blankets be examined for?
Cracks, tears and burned areas
Where are flameproof panels and diaphragms in the engine?
Nose cowl, hinged cowl panels and engine pylon.
Combustion section and gas generator also has flameproof panels.
