In Spark We Trust!
A brief history of the Aircraft Magneto
The magneto ignition system used throughout General Aviation has humble beginnings. From the early 20th century to our modern age, the Magneto has changed very little. A quant instrument maker named Hippolyte Pixii is generally considered to be the inventor of what would later be developed into the high voltage magneto. In 1832, he created a rudimentary hand-cranked device that could generate AC electrical current.
Based on the principles of electromagnetic induction, the device functioned by rotating a magnet with a hand crank over an iron core wrapped in a coil. He discovered that each time the magnet passed over the opposing pole of the coiled iron, it created a pulse of electrical current. His device was one of the first practical generators of electricity.
Similarly, to Mr. Pixii’s device, the task of modern magnetos remains the same, converting rotary motion into electrical current. The magneto that we all know and love came of age in the early 20th century. Frederick Simms along with Robert Bosch were the first to develop a practical high voltage magneto for use in internal combustion engines. The Daimler Phönix was introduced in 1899 with a Bosch magneto ignition. With the continued proliferation of the automobile, the magneto was to become a driving force in early automobile production. However, it would be a short-lived marriage.
With the onset of WWI, the automobile industry had increasingly shifted to battery-coil type ignition systems. This shift was due to lower cost, easier engine starting, decreased maintenance, and overall greater efficiency. However, the venerable magneto had found great acceptance in the fledgling aviation industry. The ruggedness of this type of ignition system lent itself well to aircraft engines where simplicity and reliability were crucial. Over one hundred years later, nearly all light general aviation aircraft continue to use a dual magneto ignition system.
The magneto has stood the test of time in its role as general aviation’s premier electrical producing instrument, but how long will that last? Many question as to why we are relying on a century-old technology when there are far better choices in today’s market. There is not an all-encompassing answer to this issue. Is it the need for redundancy, reliability factor, or even that the wheels of bureaucracy move incredibly slow? It is all of these reasons and more.
The last decade has brought about many changes in how the FAA deals with emerging technology and how they are incorporated into the general aviation fleet. Companies like Electroair, SureFLY, and others have successfully developed STC’s for many certificated aircraft in one position installations, meaning that an installation can have one EIS (electronic ignition systems) installed alongside a traditional magneto. Fingers crossed that in a few years with an increase in technical data and years of successful service, the FAA will allow an STC for a dual EIS system on certificated aircraft.
The homebuilt/experimental crowd has had great success running dual EIS systems. Not bothered with the cumbersome regulations that bog down the advancement of certificated aircraft. Operators of dual EIS systems typically report easier starting, lower operating costs, and decreased fuel consumption. Most of the same reasons the automotive industry ditched the magneto 80 years ago.
Lastly, a new challenger to the magneto and to combustion engines, in general, has emerged. The advent of battery-powered electric powerplants has gained much attention as of late. It is far too early to tell if these new electric engines are an impending revolution coming to general aviation or just merely a passing fad. With the magneto’s days in aviation being seemingly numbered, I stoically predict that this outdated ignition system will still be with us for several decades to come.
Sammy