M15.21 Engine monitoring and ground running Flashcards
How does an engine fitted with a centrifugal compressor measure engine power?
By using a ratio of engine rpm to jet pipe temperature
ow did early aial flow compreesor engines measure power?
By using a complex ratio between Pamb, (ambient pressure) to the exhaust gas temperature (p7) measured in inches of mercury
In a turbo prop or shaft engine, what can the torque monitoring system also do?
Automatically operate the aautofeather system
Assist in automatic operation of the water injection system
In a turbo prop or shaft engine, what can the torque monitoring system also do?
Automatically operate the auto feather system
Assist in automatic operation of the water injection system
Limit engine output
Balance power output between engines
Engine torque is proportional to?
Horsepower
How is torque displayed?
Torque oil pressure PSI or Ft.lbs
Torque percentage
A direct reading horsepower read out
What is the instrument that indicates torque known as?
Torque meter
What are the two most common types of torque meter?
- Hydro-mechanical, which converts engine oil pressure to a torque signal.
- Electronic, which converts the twist of the power output shaft into a torque
signal.
How is engine data recorded on an engine with hydro mechanical fuel controls?
Engines with hydro-mechanical fuel controls need an additional computer for
the parameter measurement, mainly called Power Plant Data Multiplexer
(PMUX).
How are engines fitted with and controlled by FADEC, data recorded?
On FADEC controlled engines, the data is available from the FADEC computer
(or EEC) which performs the measurement of parameters.
The data is transmitted to the Data Management Unit (DMU), which is located
in the aircraft.
The DMU records the data and compiles the ACMS reports. These reports are
printed or sent to the ground via data link.
Several types of ACMS reports are used:
* Routine reports are compiled in fixed time intervals.
* On request reports are compiled when requested by the pilot.
* Advisory reports are compiled when defined parameters exceed their limits.
What is thermo-dynamic analysis?
The wear of the components during engine operation leads to changes of the
thermodynamic variable states within the gas path.
The analysis of the data identifies the module responsible for this change.
This is done by the calculation of:
* The module quality parameters (module efficiency, absorption capacity,
airflow).
* The share of each module in EGT and fuel flow changes.
The assignment of this change to a specific module is the base for the
planning of engine removal and its overhaul.
What is mechanic-dynamic analysis?
For the identification of the vibration caused by the rotor system(s) the signals
from the vibration sensors are filtered.
The location of the unbalance on the fan rotor can also be found.
Before an overhauled engine is installed in an aircraft, a test run on the test
bench is performed.
The data recorded during this test run represents the condition of the
overhauled engine.
From this condition on, the deterioration during the engine life begins.
On a new engine, when is take of data produced?
During the first four take-offs, ACMS take off reports are generated.
These reports give the date for the calculation of the basic take-off
performance of the engine.
Later on, a take off report is generated every 35 take-offs
When are cruise report created?
Cruise reports are generated approx. every four flight hours
What method can inspect oil very accuratly?
SOAP (Spectrometric Oil Analysis Program)
