Fuel Metering Systems Flashcards
What parameters are normally sensed by a turbine-engine fuel control?
a. Power lever angle.
b. Compressor inlet total temperature.
c. Compressor RPM.
d. Burner pressure.
What is meant by trimming a turbine engine?
Adjusting the fuel control for the proper specific gravity of the fuel and for the proper idle and full throttle RPM.
What are two types of electronic fuel controls for turbine engines?
Supervisory Electronic Engine Control and Full-Authority Digital Electronic Control.
What is a FADEC?
A Full-Authority Digital Electronic Control (FADEC) is a high-precision digital electronic fuel control that functions during all engine operations. It includes the Electronic Engine Control (EEC) and functions with the Flight Management Computer (FMC) to measure the fuel to the nozzles in such a way that prevents overshooting of power changes and over-temperature conditions. FADEC furnishes information to the Engine Indication and Crew Alerting System (EICAS).
Does a turbine engine controlled by a FADEC require manual trimming?
No, this is done by the FADEC.
When should a turbine engine be retrimmed?
Any time there is a decrease in engine thrust, and after any maintenance that the manufacturer specifies as requiring retrimming.
Are the instruments installed in an aircraft suitable for use when trimming a turbine engine?
No, a special analyzer/trimmer such as a JetCal should be used.
What specifications are used to trim a turbine engine?
The data plate specifications for the specific engine. This data was obtained when the engine was calibrated in the manufacturer’s test cell.
Where should ambient temperature be measured when trimming a turbine engine?
In a shaded area as near the engine inlet as is practical.
