AS9120B, ISO 9001:2015, AND FAA AC 0056B ACCREDITED

What Are Aircraft Magnetos & How Do They Work?

Aircraft magnetos are components used to generate an electrical current to be used by the aircraft ignition system. They typically consist of a coil assembly that has a primary coil and a magnet rotor which interact with each other to generate current. The coil assembly includes a primary coil which is made up of about 200 turns of heavy copper wire wound around an iron core and a secondary coil, that of which is a thin copper wire wound around the primary coil. Next to the coils is a permanent magnet which rotates when actuated. As the magnet rotates, its poles continually change position so that a flowing current is generated in the primary coil. This current creates a powerful magnetic field in the iron core which encapsulates the whole coil assembly.

To maintain the flow of current and a magnetic field, the magneto is connected to a wire which transfers current into the ground. When creating a spark, this wire is momentarily disconnected so that the electrical current is cut off, thereby collapsing the magnetic field and generating a huge voltage spike in the secondary coil. This high voltage current then leaves the secondary coil through a high voltage tab and goes to the spark plug, where it creates the spark required for ignition. Even in very simple aircraft, there is more than one spark plug, with some aircraft having upwards of 36. As such, the high voltage spike must first enter a distributor which directs the electricity to various spark plugs in the right order.

To safeguard such components in the case of part failure, most airplanes have a dual magneto system, usually with one on either side of the engine. Having two magnetos means that if one fails, the other can take over to keep the engine running. The dual magneto system also allows for a little bit of redundancy in the event that one magneto is not generating enough power on its own. As another safety mechanism, each magento has its own self-contained electrical generator which is completely separate from the plane’s electrical system. Therefore, in the event of electrical failure, the magneto system can still work to allow the engine to stay in use.

Being such an essential part of the plane’s ignition system, one might wonder what would happen if a magneto failed mid flight. With the dual-magneto ignition system, an airplane can continue flying even if one magneto fails. However, it should be noted that the engine will run a little rougher, as it will only be receiving power from one source and firing in just half of its cylinders. Despite this reduced power, the aircraft will have adequate energy to maintain flight and safely land at its destination. If both magnetos fail, the engine will shut down, and the airplane will lose power to its engines. In order to avoid magneto failure, one should conduct regular inspections based on how often they fly. Like with any other part of an aircraft, the magnetos will also need to be cleaned and lubricated on a regular basis, and the wiring should be checked to make sure it can effectively transfer current.

Overall, the dual magneto system is an essential tool of aircraft ignition which ensures that the plane has a dependable source to power its engine. For high quality, dependable aircraft parts, such as those used in dual-magneto systems, Stacked Aviation is here to assist you with all that you require. Our vast inventory of over 2 billion new, used, obsolete, and hard-to-find components is available to customers through our easy-to-navigate website. More than that, when you source from Stacked Aviation, you can trust in the durability and authenticity of our items; as an AS9120B, ISO 9001:2015, and FAA AC 00-56B accredited enterprise, our parts and practices are subjected to strict quality standards that match the high expectations of our customers in the aviation industry. To begin the purchasing process today on any items of interest, we invite you to send us an Instant RFQ form on our website. In just 15 minutes or less of reviewing your request, a knowledgeable representative will reply with a competitive quote with time and cost savings.


June 22, 2022

Recent Twitter Posts

Semiconductor's Certifications and Memberships
The only independent
distributor with a
  • All orders are fulfilled in the USA.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.
Fallen Heroes Fund

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website ( and help in their valiant effort”.

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.