Engine Instruments Flashcards
(31 cards)
What are four common types of tachometers?
mechanical, magnetic, electric, electronic
On a turboprop with a free turbine, what tachometer readings will there be?
Ng indicates engine speed, Np indicates prop speed or free turbine speed
What are two ways a torquemeter measures torque?
shaft twist or torque pressure
Why are compressor washes performed?
To remove contaminants from the compressor and improve engine performance.
What methods are commonly used for compressor washes?
Fluid wash and abrasive grit.
How can you tell if a turbofan or turbojet engine is out of trim?
High EGT at the target engine pressure ratio for takeoff power.
What kind of markers can be used to mark the parts in hot and cold sections during repair?
Layout dye, felt tip marker, chalk.
What criteria determines replacement of a life limited part in a turbine engine?
Number of cycles, hours, or calendar time.
How are gas turbine engine tachometers calibrated?
Percent RPM.
How is EGT measured?
Thermocouples near the turbine exit.
Can the EGT system on a turbine engine be checked without running the engine?
Yes, by checking the resistance of the thermocouples.
What would be the possible cause if a gas turbine engine has high exhaust gas temperature, high fuel flow, and low RPM at all engine power settings?
A damaged or dirty turbine
What does the blue arc on a cylinder head temperature (CHT) gauge represent?
indicates the range within which operation is permitted in auto-lean.
What are the three primary controls for a reciprocating engine?
throttle, prop, mixture
Where is the carburetor air temperature guage measured?
the inlet of the carb
What two conditions can the carb air temp gauge indicate before they happen?
carb ice and detonation
What can happen if there is a high CAT gauge reading after engine shutdown on engines with a pressure carb?
trapped fuel that could cause high pressure damage, or the onset of vapor lock
What should be done if there is a high CAT gauge reading after shutdown on an engine with a pressure carb? (Prevents pressure buildup)
the fuel selector valve and throttle should be left open
What does the fuel pressure gauge on a recip measure?
the fuel pressure supplied to the carb or fuel control unit
What are four different ways fuel pressure can be measured?
bourdon tube, diaphragm, bellows, electric
On aircraft with direct fuel injection or continous flow fuel injection systems, fuel pressure is typically measured as?
a pressure drop across the injection nozzles
What instrument gives the most accurate indication of engine fuel consumption?
fuel flow indicator
What type of fuel flow reading can result if a fuel nozzle becomes clogged?
high fuel flow reading
An ____________________ system measures the volume of fuel flowing to an engine. It incorporates a moveable vane within the fuel line to the engine.
autosyn
