Aircraft Systems QZ2 Flashcards
(9 cards)
For internal cooling, air cooled engines are especially dependent on
1. A properly functioning thermostat.
2. The circulation of lubricating oil.
3. Air flowing over the exhaust manifold.
- The circulation of lubricating oil.
Explanation: While the oil system is vital to the internal cooling of the engine, an additional method of cooling is necessary for the engine’s external surface. Most small aircraft are air cooled, although some are liquid cooled.
Excessively high engine temperatures, either in the air or on the ground, will
1. Increase fuel consumption and may increase power due to the increased heat.
2. Cause loss of power, excessive oil consumption, and possible permanent internal engine damage.
3. Result in damage to heat-conducting hoses and warping of cylinder cooling fans.
- Cause loss of power, excessive oil consumption, and possible permanent internal engine damage.
Explanation: Operating the engine at higher than its designed temperature can cause loss of power, excessive oil consumption, and detonation. It will also lead to serious permanent damage, such as scoring the cylinder walls, damaging the pistons and rings, and burning and warping the valves. Monitoring the flight deck engine temperature instruments aids in avoiding high operating temperature.
If the engine oil temperature and cylinder head temperature gauges have exceeded their normal operating range, the pilot may have been operating with
1. The mixture set too rich.
2. Too much power and with the mixture set too lean.
3. Higher-than-normal oil pressure.
- Too much power and with the mixture set too lean.
Explanation: To avoid excessive cylinder head temperatures, increase airspeed, enrich the fuel-air mixture, and/or reduce power. Any of these procedures help to reduce the engine temperature. On aircraft equipped with cowl flaps, use the cowl flap positions to control the temperature. Cowl flaps are hinged covers that fit over the opening through which the hot air is expelled. If the engine temperature is low, the cowl flaps can be closed, thereby restricting the flow of expelled hot air and increasing engine temperature. If the engine temperature is high, the cowl flaps can be opened to permit a greater flow of air through the system, thereby decreasing the engine temperature.
One purpose of the dual ignition system on an aircraft engine is to provide for
1. Uniform heat distribution.
2. Improved engine performance.
3. Balanced cylinder head pressure.
- Improved engine performance.
Explanation: Most standard certificated aircraft incorporate a dual ignition system with two individual magnetos, separate sets of wires, and spark plugs to increase reliability of the ignition system. Each magneto operates independently to fire one of the two spark plugs in each cylinder. The firing of two spark plugs improves combustion of the fuel-air mixture and results in a slightly higher power output. If one of the magnetos fails, the other is unaffected. The engine continues to operate normally, although a slight decrease in engine power can be expected. The same is true if one of the two spark plugs in a cylinder fails.
What is one procedure to aid in cooling an engine that is overheating?
1. Increase the RPM.
2. Reduce the airspeed.
3. Enrich the fuel mixture.
- Enrich the fuel mixture.
Explanation: To avoid excessive cylinder head temperatures, increase airspeed, enrich the fuel-air mixture, and/or reduce power. Any of these procedures help to reduce the engine temperature. On aircraft equipped with cowl flaps, use the cowl flap positions to control the temperature. Cowl flaps are hinged covers that fit over the opening through which the hot air is expelled. If the engine temperature is low, the cowl flaps can be closed, thereby restricting the flow of expelled hot air and increasing engine temperature. If the engine temperature is high, the cowl flaps can be opened to permit a greater flow of air through the system, thereby decreasing the engine temperature.
Excessively high engine temperatures will
1. Not appreciably affect an aircraft engine.
2. Cause damage to heat-conducting hoses and warping of the cylinder cooling fins.
3. Cause loss of power, excessive oil consumption, and possible permanent internal engine damage.
- Cause loss of power, excessive oil consumption, and possible permanent internal engine damage.
Explanation: Operating the engine at higher than its designed temperature can cause loss of power, excessive oil consumption, and detonation. It will also lead to serious permanent damage, such as scoring the cylinder walls, damaging the pistons and rings, and burning and warping the valves. Monitoring the flight deck engine temperature instruments aids in avoiding high operating temperature.
If the ignition switch ground wire becomes disconnected, the magneto
1. Will not operate.
2. May continue to fire.
3. Will not operate because the battery is disconnected from the circuit.
- May continue to fire.
Even with the ignition switch in the OFF position, if the ground wire between the magneto and the ignition switch becomes disconnected or broken, the engine could accidentally start if the propeller is moved with residual fuel in the cylinder. If this occurs, the only way to stop the engine is to move the mixture lever to the idle cutoff position, then have the system checked by a qualified AMT.
An abnormally high engine oil temperature indication may be caused by
1. Operating with an excessively rich mixture.
2. Operating with a too high viscosity oil.
3. The oil level being too low.
- The oil level being too low.
Explanation: High oil temperature indications may signal a plugged oil line, a low oil quantity, a blocked oil cooler, or a defective temperature gauge. Low oil temperature indications may signal improper oil viscosity during cold weather operations.
Q3: What action can a pilot take to aid in cooling an engine that is overheating during a climb?
1. Reduce climb speed and increase RPM
2. Reduce rate of climb and increase airspeed
3. Increase climb speed and increase RPM
- Reduce rate of climb and increase airspeed
Explanation: To avoid excessive cylinder head temperatures, increase airspeed, enrich the fuel-air mixture, and/or reduce power. Any of these procedures help to reduce the engine temperature. On aircraft equipped with cowl flaps, use the cowl flap positions to control the temperature. Cowl flaps are hinged covers that fit over the opening through which the hot air is expelled. If the engine temperature is low, the cowl flaps can be closed, thereby restricting the flow of expelled hot air and increasing engine temperature. If the engine temperature is high, the cowl flaps can be opened to permit a greater flow of air through the system, thereby decreasing the engine temperature.
