PP 21

(1) Accumulation of contaminates in the compressor of a turbojet engine reduces aerodynamic efficiency of the blades. (2) Two common methods for removing dirt deposits from turbojet engine compressor blades are a fluid wash an abrasive grit blast. Both No.1 and No.2 are true. Only No.1 is true.

Why do some turbine engines have more than one turbine wheel attached to a single shaft?. To extract more power from the exhaust gases than a single wheel can absorb. To straighten the airflow before it enters the exhaust area.

Which of the following types of combustion sections are used in aircraft turbine engines?. Multiple-can, annular, and can-annular. Variable, can-annular, and cascade vane.

Why does a turbine engine require a cool-off period before shutting it down?. To allow the turbine wheel to cool before the case contracts around it. To burn off excess fuel ahead of the fuel control.

What instrument on a gas turbine engine should be monitored to minimize the possibility of a hot start?. Turbine inlet temperature. RPM indicator.

On a turbine engine with a fixed power lever position, the application of engine anti-icing will result in: A decrease in EPR. An increase in EPR.

Engine Pressure Ratio is the total pressure ratio between the: Front of the compressor and the rear of the turbine. Front of the compressor and the rear of the compressor.

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?. Turbine damage or loss of turbine efficiency. Fuel control out of adjustment.

What is the primary purpose of the tachometer on an axial-compressor turbine engine?. Monitor engine RPM during starting and to indicate overspeed conditions. Monitor engine RPM during cruise conditions.

The engine pressure ratio (EPR) indicator is a direct indication of: Engine thrust being produced. Pressure ratio between the front and aft end of the compressor.

The exhaust gas temperature (EGT) indicator on a gas turbine engine provides a relative indication of the: Temperature of the exhaust gases as they pass the exhaust cone. Inter-stage temperature.

What instrument indicates the thrust of a gas turbine engine?. Engine pressure ratio indicator. Torque meter.

In a turbine engine, where is the turbine discharge pressure indicator sensor located?. At a location in the exhaust cone that is determined to be subjected to the highest pressures. Immediately aft of the last turbine stage.

The type of lubricating oil that is used in a turbine aircraft engine is: 30–70 blend of petroleum and synthetic. Synthetic.

Which of these characteristics is desirable in turbine engine oil?. High volatility. High flash point.

Why are synthetic lubricants used in high-performance turbine engines?. The load-carrying characteristics of petroleum-based oils have a low degree of chemical stability. Synthetic oils do not require filtering and are less expensive.

What is the purpose of the last chance oil filters?. To assure a clean supply of oil to the lubrication system. To prevent blockage of the oil spray nozzle.

In a jet engine which uses a fuel-oil heat exchanger, the oil temperature is controlled by a thermostatic valve that regulates the flow of: Oil through the heat exchanger. Fuel through the heat exchanger.

In an axial-flow turbine engine, compressor bleed-air is sometimes used to aid in cooling the: Turbine, vanes, blades, and bearings. Inlet guide vanes.

Oil picks up the most heat from which of the following turbine engine components?. Turbine bearing. Compressor bearing.

Which of the following is a function of the fuel-oil heat exchanger on a turbojet engine?. Aerates the fuel. Removes oil vapors.

Why are fixed orifice nozzles used in the lubrication system of gas turbine engines?. To provide a relatively constant oil flow to the main bearings at all engine speeds. To protect the oil seals by preventing excessive pressure.

Possible failure-related ferrous-metal particles in turbine engine oil cause an indicating-type magnetic chip detector to indicate their presence by: Bridging the gap between the detector center (positive) electrode and the ground electrode. Disturbing the eddy currents around the detector tip.

What is the primary purpose of the oil-to-fuel heat exchanger?. Cool the oil. Cool the fuel.

The pumping capacity of the scavenger pump in a dry sump aircraft engine lubrication system: Is greater than the capacity of the oil supply pump. Is usually equal to the capacity of the oil supply pump.