15.19 Flashcards
Why would you use fuselage mounted power plants?
Thrust is close to the longitudinal axis
What is a firewall?
A partition between the engine and the aircraft
What are firewalls made out of?
Sheet metal shields made from stainless steel or any other heat resistant material
What two things form compartments?
Pylons and struts as well as engines
Why do engine pods in cooperate zones?
To minimise probability and spread of a fire
What are classified as fire zones?
Areas where ignition sources are present, and flammable fluid can leak
What else are isolated by firewalls?
Areas adjacent to the engine fire zone
Helicopters use firewalls to ensure that the engine is separated from what?
The gearbox or adjacent engines
What are the cowlings insulated with?
Fire resistant sheet foam
What are cowlings used in conjunction with to create a compartment designed to contain any fires or catastrophic?
Firewalls
What are fan and thrust reverser cowls used to do?
Protest engine from environment
Streamlines area
Designed to route cooling air around the engine and the components
What are the cowls constructed for mainly?
Ease of access
What is the cowling attached to?
The nacelle support frame
His is the cowling secured on the nacelle support frame?
On the 6 o’clock centreline by latches
What does the hinged cowl provide access to?
The engine core
What are the C duct also another name for?
The thrust reverser cowls
Once opened what are the C ducts supported by?
Hold-open rods
What are nacelles connected to the mounting strut by?
Hinge pins and stay fitted during engine removal
What are nacelles connected to the mounting strut by?
Hinge pins and stay fitted during engine removal
What can the translating sleeve be moved back and forth by?
Manually or by power when functional checks are required
What type of engine are acoustic panels used on?
High bypass ratio engines
What do acoustic panels utilise?
Noise absorbent liners around the inside wall of the bypass duct
Disadvantages of acoustic liners?
Add weight
Friction so increase fuel consumption
What are the C ducts also another cowls limed with to contain the noise of turbine/exhaust ?
Honeycomb panels
In what direction must engine mounts allow expansion for?
Radial and axial
What is the purpose of the engine mounts?
Weight and thrust is transmitted to the aircraft structure and mountings
What is used to connect the side mounted engines to the rear and front saddle type beams?
Through fillets
How are the beams connected to the engine mounting points?
By swinging links and thrust trunnions with a thrust strut connected to the airframe
How are pylon mounted engines mounted to the pylon?
Front and rear brackets attached to links at the top, front and rear or the engine
How are pylon mounted engines mounted to the pylon?
Front and rear brackets attached to links at the top, front and rear or the engine
Where are the actual mounting points on a pylon mounted engine?
On the front (compressor casing)
In the rear (turbine casing)
What loads do forward engine mounts take?
Vertical, side and axial (thrust) to allow for thermal expansion
What loads do the aft mounts take?
Vertical and side
What allows for expansion and torque in the main mounting bolt/trunnion?
Spherical bearings
What does the rubber bushing absorb?
Vibration
What are slinging points provided for?
Attachment of dedicated equipment for engine removal
What must you do to a fuel line when being routed near wiring to prevent it from chafing when not connected?
Route it below the wiring and clamp it to airframe
What must you avoid in flexible lines?
Tight bends
Where must wire bundles not be?
Anywhere where they can be used as a handhold or support for equipment
Wiring must be clamped low down for separation where?
Between the wire and the structure
Where the wires will touch structure, what can be used to prevent chafing?
Grommets and chafe strips
Where must wires not have a preload?
At corners and bends if grommets and chafe strips
Why must protective flexible conduits be made from a specific material?
To prevent chafing of internal wiring and inner walls
What must wiring be over hinged panels and why?
Wired and clamped to allow for twisting rather than bending
What must wiring be over hinged panels and why?
Wired and clamped to allow for twisting rather than bending when the panel is moved
What is the maximum radii for bends in wire groups or bundles?
Not less than 10 x the outside disaster if their largest wire
What is the maximum radii for bends in wires?
Not more than 6 x their outside diameter in breakouts
What is the maximum reverse direction?
6 x
What components remain within the aircraft when removing it?
Control cables and rods
Purpose of lifting points?
To safely lift up the weight of the engine
When is damage to the engine or surrounding structures most commonly occurred?
When lifting from a location that’s not the lifting points.
When is damage to the engine or surrounding structures most commonly occurred?
When lifting from a location that’s not the lifting points.
When are drains used?
In malfunction or normal operation
What does inspecting the drains achieve?
Open and clear from debris
Allows engineer to know where the debris is coming from
What does inspecting the drains achieve?
Open and clear from debris
Allows engineer to know where the debris is coming from
What are the main components of a drain system?
The drain lines which collect the fluid
The module assembly where the drain lines end
What are the main components of a drain system?
The drain lines which collect the fluid
The module assembly where the drain lines end
What does the lower part of the lower assembly consist of?
Drain mast
What is the drain collector assembly also known as and what does it do?
The manifold module and it keeps fluid leaks in small tanks
What does the drain line collect?
Fluid and vapour from points where lines may leak or where fluid can build up in cavities
