Power instilations Flashcards
Where are engines installed
Inside the nacelle which gives aerodynamic smoothness and protects the engine components
What damage is allowed in the nacelle
Small dents , limitations found in the amm
What class are critical parts
Class 1 aerodynamic smoothness
How do we get undisturbed airflow around the pylon
By specially shaped covers called fairings
Air inlet cowling parts
Outer and inner barrel
Nose lip
Forward and aft bulkhead
How is air inlet cowling connected to engine flange
By bolts & there are two index pins
Why do some engines have unsymmetrical inlets
Use different air inlet cowlings on the left and right engine
How are cowlings supported
Single or dual telescopic hold open rods
Fan cowling latch angles
40-55
What does fan reverse cowling do
Guides fan airflow in either forward or reverse direction
How is cowling opened
Due to its weight it’s opened with assistance of hydraulic pressure from hydraulic hand pump
How do we prevent blade tip rub
The cowling forming a stiff case to support structural stability
How cowlings stiffened
V shaped grooves and blades
What causes tip rub
High aerodynamic loads
What are the two passive fire protection features
Fire protective coating & fire seal
What material is the fire seal
Titanium with heat resistant silicon layer
What does core cowling do
Covers the hot section of engine
How is the core cowling sometimes combined
With the fan reverser cowling
Exhaust nozzle components
Centre body & exhaust sleeve
What uses a reduced exhaust signature
High bypass fan engines
What material is the acoustic panel in low temperature areas
Lightweight composite
What material is the acoustic panel high temperature areas
Fibrous-metallic materials
When does pressure relive door open
Overpressure in compartment
How is the pressure relief door held in a closed position
By a spring
What are engines installed on
Pylon or engine strut
How many engine mounts is there
2 mounts
One fwd and one aft
What axis does engine weight act on
Vertical or z axis
What axis does engine thrust work on
Longitudinal or rotational axis
What mount is engine thrust transferred by
Only by fwd mount
What axis do side loads act in
Lateral axis or y axis
What do vibrational and flight manoeuvres do negatively
Generate additional loads in all directions
What loads do attachments bolts carry
Vertical engine loads
How are thrust and side loads transferred
Shear pins
What direction does fwd engine mount transfer forces
Y and z , which are weight and side loads
What loads do aft mount transfer
Only vertical loads
How is vibration and torque effects reduced on turboprop instillation
Resilient rubber mounts and links
When would the mount be rejected during inspection
If cracking or pitting is found
During inspection if anything is found it’s rejected apart from what
Surface corrosion dependent on amm instructions
How do you identify bayonet design
Three separate threads
What’s the standard method for removing wing mounted engines
Bootstrap method
What the good and bad about crane sling method
30% less time then bootstrap method but needs expensive equipment
How can you identify crane supported sling method
G shaped arm
Good and bad about uplifter loader method
40% less time then bootstrap but needs expensive special equipment
How are control lever knobs shaped and coloured
Differently for identification purposes
What’s the final adjustment and alignment of control system
Control rigging
How are rigging pins fitted
With a red flag
If the same travel is made by two levers linked together what happens with the angle
The angle between them and interconnecting rod must be the same
When control rigging why do we carry out engine run
Power check and synchronisation
Why do engines need a drain system
Take all leakages of fluid directly overboard
2 Main components of drain system
Drain lines & module assembly
Where is the drain mast and what does it do
Lowest part of module and it carries fuel overboard
Where are fluid leaks collected from
All Drive pad seals on gear box
Where are most drain outlets found
On pylon
What’s the most important outlet do
Drains fuel overboard
Why is it important to have outler drain
So fuel leak from the main fuel supply can’t collect in the pylon and drip into engine
How do drain lines end
At drain mast with a specific hole
How is leakage flow
Horizontal due to airstream
What does horizontal leakage flow do
Provide visable track on drain mast so u can identify the origin of leak
How do u check if leakage is acceptable or not
By checking leak rate
What do you use for a leak rate check
Collect fuel in small plastic bottle and compare to limits in amm
What does a drain collector assembly do
A method of checking leak rates
What happens when leak collector is full
Overflow into holding tank
Where are holding tanks emptied
By ram air that enters on front side of drain mast
What airspeed are tanks pressurised
200kts
How are collectors emptied manually
Spring loaded drain valves
What are fire walls made of
Steel and titanium
