How Do Aircraft Magnetos Work?

Magnetos are essential in upholding engine operations for many types of aircraft, providing the necessary ignition power for fuel-and-air mixture combustion. While magnetos are an old technology that is primarily found within piston engines, their reliable performance has kept them as a staple in countless models. In this blog, we will explore the inner workings of magnetos, discussing their design, common types, and why certain aircraft continue to use them despite alternative systems existing.

How Aircraft Magnetos Work

An aircraft magneto can be considered as a specialized type of generator that produces electrical energy to power the ignition system of an aircraft engine. It is an entirely self-contained device, meaning it does not rely on external electrical power to function. If there is a failure in the electrical system, the magneto will continue to provide spark energy, ensuring that the engine remains operational. This inherent reliability is one reason why magnetos are still widely used in many aircraft today.

Magnetos function on the principle of electromagnetic induction, leveraging key components like a stator, rotor, and ignition coil to create the energy necessary for combustion. The stator is a stationary part of the magneto, while the rotor is an element that spins within it. As the rotor rotates, it generates a magnetic field by passing magnets near the stator. This movement induces an electrical current in the ignition coil, which is responsible for amplifying the voltage. Once the voltage reaches a certain threshold, the magneto discharges a high-voltage current to devices known as spark plugs, which then ignite the fuel-air mixture inside the engine’s cylinders.

Common Types of Aircraft Magneto Systems

There are several types of magneto systems used in aircraft, each featuring a unique design to benefit specific operational needs.

Single Magneto Systems: These options are relatively straightforward, only having one magneto that powers all the spark plugs in an engine. These systems are generally employed in smaller and older aircraft that require basic functionality, where more complex setups are unfeasible. While simple in setup and use, single magnetos can present a disadvantage with no backup options available in case of a failure.

Dual Magneto Systems: Now a standard feature in many modern aircraft engines, dual magneto setups are where two independent magnetos power their own set of spark plugs. The primary advantage of this design is redundancy, as the engine can continue to operate even if one magneto should fail. Dual magnetos also allow for more efficient combustion, as having two sparks ignite a fuel-air mixture results in a more complete and uniform burn.

Impulse Coupling Magneto Systems: Impulse coupling magnetos are a more specialized type that provide a delayed spark at low engine speeds, ensuring that the fuel-air mixture ignites effectively when it is turned over during start-up.

Why Do Some Aircraft Use Magnetos and Others Not?

While magnetos are commonplace in piston engines, not all aircraft use this form of ignition system, or engine type for that matter. The primary reason some aircraft utilize magnetos is their provided independence from an airplane's electrical system, allowing for increased safety in the event of an issue or failure. This self-sufficiency makes magnetos a popular choice in general aviation, where maintaining safety and reliability is of the highest concern.

In contrast, modern aircraft with turbine engines or other advanced power plants forgo the magneto system, igniting engine mixtures with electricity derived from the onboard electrical system or an auxiliary power unit (APU). These systems are more complex, though they offer greater control for the benefit of more demanding engines. Since larger aircraft are more capable of facilitating the addition of dependable electrical infrastructure, these advanced forms of ignition are less available for general aviation models.

Where to Purchase Magneto Parts

Whether you are currently in the market for reliable stators, rotors, ignition coils, or other various parts for your aircraft magneto system, look to Rapid NSN and our extensive product offerings. Owned and operated by ASAP Semiconductor, we offer customers access to an unrivaled selection of products that currently exceeds 2 billion new, used, obsolete and hard-to-find listings. With the curated catalogs presented on our website and an online Request for Quote (RFQ) service, we have simplified the process of locating parts and obtaining tailored pricing information for comparisons. Our staff is also just a call or email away from providing tailored service and consultation, so reach out any time to discover how we can assist you.