3L Airplane Systems - Electrical System Flashcards
- Describe the electrical system on this aircraft.
Electrical energy is provided by a 28-volt, direct-current system, powered by an engine-driven 60-amp alternator and a 24-volt battery.
- Where is the battery located?
The battery is located aft of the rear cabin wall.
- How are the circuits for the various electrical accessories within the aircraft protected? (FAA-H-8083-25)
Most of the electrical circuits in an airplane are protected from an overload condition by either circuit breakers or fuses or both. Circuit breakers perform the same function as fuses except that when an overload occurs, a circuit breaker can be reset.
- What is a bus bar? (FAA-H-8083-25)
A bus bar is used as a terminal in the aircraft electrical system to connect the main electrical system to the equipment using electricity as a source of power. This simplifies the wiring system and provides a common point from which voltage can be distributed throughout the system
- The electrical system provides power for what equipment in an airplane?
Normally the following:
a. Radio equipment
b. Turn coordinator
c. Fuel gauges
d. Pitot heat
e. Landing light
f. Taxi light
g. Strobe lights
h. Interior lights
i. Instrument lights
j. Position lights
k. Flaps (maybe)
l. Stall warning system (maybe)
m. Oil temperature gauge
- What does the ammeter indicate? (FAA-H-8083-25)
It shows if the alternator/generator is producing an adequate supply of electrical power to the system by measuring the amperes of electricity, and also indicates whether the battery is receiving an electrical charge. If the needle indicates a plus value, it means that the battery is being charged. If the needle indicates a minus value, it means that the generator or alternator output is inadequate and energy is being drawn from the battery to supply the system.
- What function does the voltage regulator have? (FAA-H-8083-25)
A voltage regulator controls the rate of charge to the battery by stabilizing the generator or alternator electrical output. The generator/alternator voltage output is usually slightly higher than the battery voltage. For example, a 12-volt battery would be fed by a generator/alternator system of approximately 14 volts. The difference in voltage keeps the battery charged.
- Does the aircraft have an external power source receptacle, and if so where is it located?
Yes, the receptacle is located behind a door on the left side of the fuselage aft of the baggage compartment door.
- What type of ignition system does your airplane have? (FAA-H-8083-25)
Engine ignition is provided by two engine-driven magnetos, and two spark plugs per cylinder. The ignition system is completely independent of the aircraft electrical system. The magnetos are self-contained units supplying electrical current without using an external source of power. However, before they can produce current, the magnetos must be actuated as the engine crankshaft is rotated by some other means. To accomplish this, the aircraft battery furnishes electrical power to operate a starter which, through a series of gears, rotates the engine crankshaft. This in turn actuates the armature of the magneto to produce the sparks for ignition of the fuel in each cylinder. After the engine starts, the starter system is disengaged and the battery no longer contributes to the actual operation of the engine.”
Excerpt From: Michael D. Hayes. “Commercial Oral Exam Guide.” Aviation Supplies and Academics, Inc., 2013-08-23. iBooks.
This material may be protected by copyright.
Check out this book on the iBooks Store: https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewBook?id=728079535
- What are the two main advantages of a dual ignition system? (FAA-H-8083-25)
a. Increased safety—in case one system fails the engine may be operated on the other until a landing is safely made.
b. More complete and even combustion of the mixture, and consequently improved engine performance; i.e., the fuel/air mixture will be ignited on each side of the combustion chamber and burn toward the center.
