15.21 Flashcards
Who should you inform to do an engine run?
Air traffic control
If a ground run is taking place with cowlings open or carrying out pressure run, who should attend?
Fire tender
Three sections of engine monitoring systems?
• Performance monitoring
• System monitoring
• Condition monitoring
For Engine pressure ratio (EPR), what ratio is measured?
the ratio of the jet pipe pressure to the compressor (Fan) inlet pressure
How do centrifugal compressor engines measure engine power?
By comparing the relationship between engine rpm and jet pipe temperature
Why can’t axial flow compressors use the same power measurements as centrifugal compressors?
as there is no direct relationship between engine rpm and thrust
Torque monitoring systems are used to indicate what to where?
indicates to the flight deck the power developed by a turbo-prop or turbo-shaft engine
Engine torque is proportional to what?
Horse power
How is engine torque transmitted?
transmitted through the propeller reduction gear or the power output shaft
How is torque displayed in the cockpit?
• Torque oil pressure (psi or ft. lbs)
• Torque percentage
• Sometimes a direct horse-power read-out
What is the instrument that indicates torque?
Torque meter
Modern engines use what type of accelerometer to measure vibration?
Piezoelectric
Where are accelerometers normally fitted?
One to the fan or LP casing
Other attached to turbine casing
What is hard time?
preventative process which involves the removal of items for overhaul or replacement at specified intervals
What are the hard time intervals?
Can be calendar dates
Number of landings or cycles
