Welcome Guest. Sign in or Signup

1 Answers

Are magnetos on the same electrical system as the battery?

Asked by: 3408 views , ,
Aircraft Systems

Do mags ground to the same source as the battery and other electric consumers?  If my battery explodes or I take a lightning strike that fries my electrical system, would my magnetos be affected?  If the positive terminal on the battery somehow contacts the airframe (ground), could it fry my mags as well since everything is connected via ground?

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

1 Answers



  1. John D Collins on Sep 09, 2015

    The magneto’s and the ignition system for your engine are not connected to the battery. They are independent. Most aircraft have dual magnetos and each cylinder has two spark plugs, one attached to each magneto for redundancy. The magnetos derive the spark energy from permanent magnets that induce a current in the magneto coil windings. The voltage is stepped up in the magneto to a sufficiently high voltage to generate the spark and a distributor switches the high voltage to the spark plug wires.

    For metal aircraft, the current from a lightning remains on the surface metal skin of the aircraft and often won’t affect the electrical system directly. It may burn a hole where the aircraft is struck and where the bolt exits the aircraft. An exploding battery would be a bad problem as it would be a fire hazard. In either of these scenarios, the engine is likely to remain running, but you may have bigger issues with the airframe integrity. If you were hit by lightning, you are probably in or near a thunderstorm, which is no place to be in the first place.

    +3 Votes Thumb up 3 Votes Thumb down 0 Votes


The following terms have been auto-detected the question above and any answers or discussion provided. Click on a term to see its definition from the Dauntless Aviation JargonBuster Glossary.

Answer Question

Our sincere thanks to all who contribute constructively to this forum in answering flight training questions. If you are a flight instructor or represent a flight school / FBO offering flight instruction, you are welcome to include links to your site and related contact information as it pertains to offering local flight instruction in a specific geographic area. Additionally, direct links to FAA and related official government sources of information are welcome. However we thank you for your understanding that links to other sites or text that may be construed as explicit or implicit advertising of other business, sites, or goods/services are not permitted even if such links nominally are relevant to the question asked.