Module 15.21 Operation and monitoring Flashcards
What effect does moving the throttle lever from the idle have?
Causes the fuel control system to supply more fuel as the engine increases
What position must the throttle lever be in for thrust reversers to deploy?
Idle
How should the aircraft be positioned for an engine run up?
Into the wind with chocks fitted and brakes on
What distance in front of the engine on a run-up must be clear?
10m
Does ATC need to be informed of a ground run?
Yes, permission, duration and ground run type must be given
Should the beacon lights be on during an engine ground run?
Yes
When the engine/s are running, what can be carried out?
Engine trimming
Why must both engines be run?
To prevent asymmetry
When can engine power be increased above idle?
When absolutely necessary
When carrying out acceleration checks on aircraft engines, what engine must be used as datum?
The oldest engine
How long should the engine be left at idle before turning off to allow for cool down?
5 mins
What indications are used for engine monitoring?
- EPR
- N1 and N2 (N3)
- FF
- EGT
How do centrifugal compressor engines measure engine power?
Engine RPM and Jet Pipe Temperature (JPT)
What is the EPR the ratio between?
Jet pipe pressure and compressor inlet
What method of power measurement do axial flow bypass engines use?
EPR
Torque monitoring systems are used to indicate the power on what engines?
Turboprop and turboshaft
Torque monitoring systems can also be used for what?
- Auto operate feathering system
- Assist in auto operation of water injection system
- Limit engine output
- Balance power between engines
What are the methods of displaying torque in the flight deck?
- Torque oil pressure
- torque percentage
- Direct horsepower read out
What are the two types of torque sensing systems?
- Hydromechanical
- Phase displacement
When would an engine be removed?
Change of time limited parts or repair of damages
What performs the aircraft data recording?
Aircraft Condition Monitoring System (ACMS)
What compiles the ACMS data reports?
Data Management Unit
How can these ACMS reports be accessed? (Aircraft condition monitoring system)
Printing or via ground data link
What does thermodynamic analysis identify?
Wear of gas path components during engine operation
Mechanic-dynamic analysis identifies what?
Vibration caused by fan and turbine systems
For how many takeoffs is an ACMS report generated for after engine installation?
4 take-offs
Later on, a take-off report is generated after how many take-offs?
35 take-offs
The system selects a stable cruise condition for generation of what report?
Cruise report
Where are these cruise and take-off reports stored?
Engine database
What are the two ways of finding particles in the oil?
- Magnetic chip detectors
- SOAP
Magnetic particles can divided into what 4 groups?
- Swarf
- Magnetic fines
- Metal flakes
- Chip
What are magnetic fines shown as on the MCD?
Black sludge
Where are metal flakes from?
Gear teeth and bearings
What is a boroscope inspection?
Internal visual inspection of the engine
Where are the vibration accelerometers located?
fan or LP casing and turbine casing
What is the most common defect found while inspecting the hot section?
Cracking
When will dye or chalk be used to mark parts?
Directly exposed to gas path
When will wax marking pencil be used?
Not exposed to gas path
To inspect the combustion chamber for cracks what methods are used?
Visible dye and fluorescent penetrant
How can fuel nozzles be cleaned?
Cleaning fluid and soft bristle brush
How are turbine blades inspected and cleaned?
Same manner as compressor blades
Where do stress cracks appear on the turbine blades?
Cracks on LE or TE
Deformation of the blade caused by over-temperature may appear as what?
Waviness
When can a compressor clean (desalinisation wash) be carried out?
While motoring the engine over on the starter or running the engine at idle
