Even though this is an issue focused on emergencies, one thing should be clear: An electrical failure on a daytime VFR flight does not make an emergency. Nuisance should be a better way to describe it. A total electrical failure at night or in the clouds is a much more significant event. Even so, recognizing the symptoms of a failure and how to treat it is important regardless of when, what, and where you may be flying.
Most light aircraft have a basic electrical system consisting of a battery, alternator or generator, a voltage regulator, and at least one electrical bus that connects available power to those items that need it. The magnetos are their own self-contained system, a benefit of which is that if the electrical system goes to bed. The engine will keep running.
1. You can detect an impending electrical failure by noting a significant left deflection on the ammeter, with flickering radios, irregular audio system volume, or with an annunciator light.
2. Reset any circuit breakers. Only once, please. You don't want to damage the unit or cause a fire.
3. Cycle the alternator by turning Off the master switch or, in the case of a split switch, just the alternator side.
4. If power isn’t restored, turn off the alternator and conserve energy by turning off all nonessential equipment. The transponder and radios are big current draws. All lights also can be turned off.
5. If radios are needed, make sure the battery switch is on; advise ATC that you have had an electrical failure and you expect to lose radio communications.
6. Plan and execute a no-flap landing if necessary. Expect to come in slightly faster and at a flatter attitude. No-flap landings also take up more runway.
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