15.21 Operating & Monitoring Flashcards
What must be done when positioning the aircraft for an engine run?
Face aircraft into the wind.
Apply brakes.
Clear obstructions.
No aircraft 10m infornt of engine intake.
Check oil levels
Position CO2 extinguisher.
During acceleration checks, what is the datum (reference)?
The oldest engine.
After operating at high power, how long should an engine cool down for?
5 mins at idle power.
What is the purpose of engine cool down period?
Prevents rotor seizures.
When do you do engine trimming?
When engines are running.
When must engine asymmetry be considered?
When you’re only running 1 engine.
What are the 3 parameters indication groups?
Performance monitoring.
System monitoring.
Condition monitoring.
What indications are used for engine monitoring?
EPR
Rotor speed, N1, N2, (N3)
Fuel Flow
EGT
What is the low pressure rotor speed?
N1
What is the high pressure rotor speed?
N2, N3 on 3 spool engine.
How do axial flow bypass engines indicate thrust?
Using EPR as rotor speed is not proportional.
What do torque monitoring systems indicate?
Power developed by a turboprop or turboshaft engine.
What can the torque monitoring system be used for?
To automatically operate propeller feathering system.
Assist automatic operation of water injection system.
Limit engine power output.
Balance power between engines.
What ways can torque be displayed?
Torque oil pressure.
Torque percentage.
Direct horsepower read out.
What instrument is used to indicate torque?
Torque meter
What are the 2 sensing systems used on turboshaft and turboprop engines?
Hydro mechanical.
Electronic /Phase displacement.
How does the electronic sensing system work?
The phase difference is measured between 2 shafts, which is converted to an electronic signal to indicate torque.
When is an engine removed?
Only for change of life limited parts or damage repairs.
What records data onboard the aircraft?
Aircraft Condition Monitoring System (ACMS)
Where is ACMS data transmitted?
To Data Management Unit (DMU)
What does the DMU do?
Records data and complies a ACMS report.
How are ACMS reports accessed?
Printed or sent to the ground via link.
What does thermodynamic analysis do?
Identifies wear of gas path components.
What does mechanic dynamic analysis do?
Identifies vibration caused by the fan and turbine rotor system.
