15.21 - Operation And Monitoring Flashcards
(22 cards)
Engine assurance checks
Checks acceleration and deceleration time
Oldest engine is used as a datum.
Engine trimming can be carried out.
Where is engine trend monitoring data stored.
Data management unit
ACMS ircraft condition monitoring system.
When does ACMS generate reports
During the first 4 take-offs for that engine, or every 35 take-offs after that.
Reports can be advisory, when a limit is exceeded. Or they can be made on request of the flight crew.
Mechanic-dynamic analysis
Analysis of vibration caused by the fan and turbine.
Thermodynamic analysis
Identifies wear of gas path components.
Temps and pressures.
Why is engine trend monitoring helpful
Means an engine can be removed before the damage has fully developed
Limits operational costs.
What is a ground run up
Running the engine on the ground so that engine trimming can be done if required to prevent asymmetry problems.
Engine shutdown
When ran for extended periods it is recommended to idle for 5 minutes to prevent possible seizure of rotors.
What is SOAP
Spectrometric oil analysis programme.
Magnetic particles
4 groups:
Swarf
Magnetic fines
Maella flakes
Chip.
Where do metal flakes in oil come from
Bearings.
Magnetic fines in oil.
Black sludge
Can look like metal flakes ut aren’t
Come from worn areas of the gear box and engine and are generally acceptable.
Chips in oil
Very thick flakes that usually have one smooth machined surface
Gear teeth flakes in oil
Shiny with an irregular shape
Can look the same as solder splashes.
What is the unit for vibration
Accelerations are given in inches per second or millimetres per second.
How can compressor blades be reworked
With emery cloth or hand files.
How to clean fuel nozzles
Soft bristle brush and approved cleaning fluid.
Inspection of combustion section
Most common defect is cracking
Layout dye or chalk can be used for marking out.
Inspect for cracks with dye.
Cracks, nicks or dents are normally cause for component replacement.
Inspection of turbine section
Cracks are not permitted
Stress cracks appear on leading or trailing edge
Deformation due to overtemp is only found on the leading edge.
Compressor washing
Contaminants are mostly salt and pollution
Fresh water is used - called a desalination wash.
Performance recovery wash.
Used when a desalination wash is not sufficient.
Heated water can be used or an emulsion type surface cleaner.
More vigorous type of wash
May be necessary.
Cleaning compressor by injection of abrasive grit
Very vigorous and mostly applicable to centrifugal type compressors.
