21 - Operation and Monitoring Flashcards
What position must thrust levers be in before being moved to the reverse setting
Idle
What must be checked before an engine start
Free movement of turbine and compressor and area is clear of FOD
What unit starts engines on multi-engine aircraft
APU or ground air power unit
What is neccessary to monitor engine for hot start
- Speed
- Oil pressure
- EGT
What can be carried out when an engine is running
Engine trimming
Why must engines be run on both wings when engine mounted
To reduce asymetric thrust
Why can engine power not be increased more than neccessary
Excessive engine heating and cooling redcues lifespan
What must be used as the datum when carrying out engine acceleration tests
The oldest engine
When should a 5 minute wait for engine cooldown be implemented
After an extended period of high power levels
What does N1 indicate
Low pressure spool speed
What does N2 indicate
High pressure spool speed
Why is EGT measured
To measure overheating
How do centrifugal compressors measure power
RPM and Jet Pipe Tempreature relationship
What can a torque monitoring system be used for?
- Automatic prop feathering
- Automatic water injection
- Engine power output mangement
- Balance power on multi-engines
What is engine torque propotional too
Horsepower
How is torque displayed
- Torque oil psi
- Percentage
- Direct horsepower readout
What is the name of the instrument to indicate torque
Torque meter
What are the types of torque sensing elements used
- Hydro-mechanical
- Electronic
- Phase displacement
How is thermodynamic analysis calculated
- Module quality parameters
- Share of each module in EGT and fuel flow changes
How often is a take-ff performance generated
For the 1st four, then every 35
Where are take-off performances stored
Engine database
What is SOAP
Spectrometric Oil Analysis Program
What are ferrous particles boiled in
Nitric acid
What provides an indication of the internal condition of the engine and gearbox
Magneti chip detector (MCD)
When is the MCD checked
At regular intervals or recommended by manufacturer
What are the 4 types of magnteic chips that can be detected
- Swarf
- Magnetic fines
- Metal flakes
- Chip
Define swarf
Unwanted material when components are machined, left in engine/gearbox
Define magnetic fines
Shown as black sludge on the MCD. When sludge is removed, fines look like flakes
Define metal flakes
Come from ball bearings, roller bearings, bearing tracks and gear teeth. They have different shape depending on source
Explain a boroscope inspection
General internal inspection using a rigid, flexible or electronic probeH
