Aircraft Systems Flashcards
What is a magneto?
A self contained source of electric energy, so even if an aircraft loses total electric power, the engine will continue to run.
What happens when checking magneto operation prior to flight?
Smooth on both and a slight drop in RPM on only one.
How does a carburetor induction system work?
Outside air flows into the carburetor and through a Venturi (a narrow throat in the carburetor). When air flows through the Venturi, a low pressure area is created. This low pressure allows the fuel to flow and mix.
Why do you need to adjust the fuel/air mixture at altitude?
The mixture becomes richer as you gain altitude because the carburetor meters the same amount as at sea level but the air is now less dense. Decreasing the rate of fuel discharge compensates for the decrease in air density.
In what conditions can carburetor ice form?
20-70 degrees Fahrenheit and when the relative humidity is high.
What happens when carburetor heat is applied?
Preheated air enters the carburetor, this hot air is less dense and causes the fuel/air mixture to be enriched. This decreases engine output and increases engine operating temperatures.
What is the first indication of carburetor ice?
A decrease in RPM as the air supply is cut off
What happens when carburetor heat is applied?
Air density will decrease, causing the RPM to drop even lower. Then as the ice melts, the RPM will rise gradually.
What is detonation?
Uncontrolled spontaneous explosion of the mixture in the cylinder. Can be caused by the use of low grade fuel or a fuel/air mixture that is too lean. If the proper grade fuel is unavailable, use the next grade up.
How does water enter the fuel tanks?
The air in the tanks can cool at night, and this cooling forms water droplets on the inside. Filling tanks completely can prevent this.
Explain the two fuel pumps
One is engine driven, the other is an electric auxiliary pump to add reliability and aid in engine starting.
What can be done to help cool an engine that is overheating in flight?
Reduce rate of climb, increase airspeed, enrich the fuel mixture, reduce the throttle.
What 4 things can cause excessively high engine temperatures?
1- Too lean a mixture
2- Too low a grade of fuel
3- low oil
4- insufficient air flow
In a constant speed propeller aircraft, what gauges do the throttle and propeller control?
The throttle controls the power output as shown on the manifold pressure gauge. The propeller regulates the engine RPM.
What is a precaution for the operation of an engine equipped with a constant-speed propeller?
Avoid high manifold pressure settings with low RPM
