How do the turbines which are driven by the exhaust gases of a turbo compound engine contribute to total engine power output?
By driving the crankshaft through suitable couplings. By converting the latent heat energy of the exhaust gases into thrust by collecting and accelerating them. By driving the supercharger, thus relieving the engine of the supercharging load.
Which of the following statements most accurately describes spark plug heat range?
The length of the threaded portion of the shell usually denotes the spark plug heat range. A hot plug is designed so that the insulator tip is reasonably short to hasten the rate of heat transfer from the tip through the spark plug shell to the cylinder head. A cold plug is designed so that the insulator tip is reasonably short to hasten the rate of heat transfer from the tip through the spark plug shell to the cylinder head.
If the hot clearance is used to set the valves when the engine is cold, what will occur during operation of the engine?
The valves will open early and close early. The valves will open late and close early. The valves will open early and close late.
Which of the following types of electric motors are commonly used in electric tachometers?
Direct current, series wound motors. Synchronous motors. Direct current, shunt-wound motors.
A turbine engine compressor which contains vanes on both sides of the impeller is a,
double entry centrifugal compressor. single entry axial flow compressor. double entry axial flow compressor.
If staggered ignition timing is used, the,
spark will be automatically advanced as engine speed increases. spark plug nearest the exhaust valve will fire first. spark plug nearest the intake valve will fire first.
If the intake valve is opened too early in the cycle of operation of a four-stroke cycle engine, it may result in,
engine kickback. backfiring into the induction system. improper scavenging of exhaust gases.
Excessive valve clearances will cause the duration of valve opening to,
increase for both intake and exhaust valves. decrease for both intake and exhaust valves. decrease for intake valves and increase for exhaust valves.
What is the relationship between the accelerating pump and the enrichment valve in a pressure injection carburetor?
Unmetered fuel pressure affects both units. No relationship since they operate independently. The accelerating pump actuates the enrichment valve.
What are the three basic regulating components of a sea level boosted turbocharger system?
1. Exhaust bypass assembly.
2. Compressor assembly.
3. Pump and bearing casing.
4. Density controller.
5. Differential pressure controller.
2, 3, 4. 1, 2, 3. 1, 4, 5.
When checking the idle mixture on a carburetor, the engine should be idling normally, then pull the mixture control toward the IDLE CUTOFF position. A correct idling mixture will be indicated by:
an increase of 10 to 50 RPM before decreasing. a decrease of 20 to 30 RPM before quitting. an immediate decrease in RPM.
According to Federal Aviation Regulations, oil tank fillers on turbine engines must be marked with the word,
oil and the type and grade of oil specified by the manufacturer. oil and tank capacity. oil.
Why does the smoothness of operation of an engine increase with a greater number of cylinders?
The engine has larger counterbalance weights. The power impulses are spaced farther apart. The power impulses are spaced closer together.
Carburetor icing may be eliminated by which of the following methods?
Ethylene glycol spray and heated induction air. Alcohol spray and heated induction air. Alcohol spray and electrically heated induction duct.
Select the statement which is correct relating to a fuel level check of a float type carburetor.
Use 5 pounds fuel pressure for the test if the carburetor is to be used in a gravity fuel feed system. Block off the main and idle jets to prevent a continuous flow of fuel through the jets. Do not measure the level at the edge of the float chamber.
The amount of voltage generated in any magneto secondary coil is determined by the number of windings and by the,
rate of collapse of the magnetic field around the primary coil. amount of charge released by the capacitor. rate of buildup of the magnetic field around the primary coil.
Where would one find type design information for an R1830-92 engine certificated under the Civil Air Regulations (CAR) and installed on a DC-3?
The Aircraft Engine Type Certificate Handbook. The Aircraft Engine Specifications. The Aircraft Specifications and Type Certificate Data Sheet.
An advantage of the centrifugal flow compressor is its high,
ram efficiency. peak efficiency. pressure rise per stage.
What is the purpose of an exhaust outlet guard on a small reciprocating engine?
To shield adjacent components from excessive heat. To prevent dislodged muffler baffles from obstructing the muffler outlet. To reduce spark exit.
If it is found that a shielded ignition system does not adequately reduce ignition noise, it may be necessary to install,
bonding wires from the shielding to ground. a filter between the magneto and magneto switch. a second layer of shielding.
What is the function of a fire detection system?
To activate a warning device in the event of a powerplant fire. To identify the location of a powerplant fire. To discharge the powerplant fire extinguishing system at the origin of the fire.
How is anti icing fluid ejected from the slinger ring on a propeller?
By centrifugal force. By pump pressure. By centripetal force.
Which of the following lubrication system components is never located between the pressure pump and the engine pressure system?
Fuel line for oil dilution system. Oil temperature bulb. Check valve.
Which of the following would indicate a general weak engine condition when operated with a fixed pitch propeller or test club?
Lower than normal manifold pressure for any given RPM. Manifold pressure lower at idle RPM than at static RPM. Lower than normal static RPM, full throttle operation.
When will the voltage in the secondary winding of a magneto, installed on a normally operating engine, be at its highest value?
Toward the latter part of the spark duration when the flame front reaches its maximum velocity. Immediately after the breaker points close. Just prior to spark plug firing.
What operational force causes propeller blade tips to lag in the opposite direction of rotation?
Aerodynamic twisting force. Thrust bending force. Torque bending force.
What method is ordinarily used to make idle speed adjustments on a float type carburetor?
An orifice and adjustable tapered needle. An adjustable needle in the drilled passageway which connects the airspace of the float chamber and the carburetor venturi. An adjustable throttle stop or linkage.
The throttle valve of float type aircraft carburetors is located,
ahead of the venturi and main discharge nozzle. after the main discharge nozzle and ahead of the venturi. between the venturi and the engine.
What is the best indication of worn valve guides?
Low compression. High oil consumption. Low oil pressure.
Prolonged idling of an engine will usually result in,
increased oil consumption. excessive cylinder head temperatures. foreign material buildup on spark plugs.
A gas turbine engine comprises which three main sections?
Compressor, diffuser, and stator. Turbine, compressor, and combustion. Turbine, combustion, and stator.
If a fire starts in the induction system during the engine starting procedure, what should the operator do?
Turn off all switches. Continue cranking the engine. Turn off the fuel switches to stop the fuel.
Which statement is correct concerning a thermocouple type temperature indicating instrument system?
It is a balanced type, variable resistor circuit. It usually contains a balancing circuit in the instrument case to prevent fluctuations of the system voltage from affecting the temperature reading. It requires no external power source.
What is the purpose of the check valve generally used in a dry sump lubrication system?
To prevent the oil from the pressure pump from entering the scavenger system. To prevent the scavenger pump from losing its prime. To prevent the oil from the supply tank from seeping into the crankcase during inoperative periods.
An unsupercharged aircraft reciprocating engine, operated at full throttle from sea level, to 10,000 feet, provided the RPM is unchanged, will:
lose power due to the reduced density of the air drawn into the cylinders. produce constant power due to the same volume of air drawn into the cylinders. lose power due to the reduced volume of air drawn into the cylinders.
Arcing at the brushes and burning of the commutator of a motor may be caused by,
excessive brush spring tension. weak brush springs. low mica.
Which of the following fire detectors are commonly used in the power section of an engine nacelle?
CO detectors. Rate of temperature rise detectors. Smoke detectors.