Electronic Ignition, the SureFly Magneto, and Trading a Hundred-Year-Old Spark for Software on the Oshkosh Exhibit Floor

SUMMARY: SureFly’s electronic ignition module replaces one magneto on certified aircraft, offering better fuel burn and easier starts while keeping a magneto backup.

Electronic ignition has finally reached the certified fleet, and the clearest example is the SureFly ignition module, a computerized unit that replaces one of your two magnetos while leaving the other in place. Now part of the Continental family, SureFly holds Supplemental Type Certificates (STCs) covering a growing list of Lycoming and Continental engines, and the upgrade is available today. The payoff is variable spark timing, better fuel efficiency, easier starting, and less scheduled maintenance - without giving up the self-powered magneto backup pilots have relied on for over a century.

What Is a Magneto, and Why Has It Survived So Long?

A magneto is a self-contained spark generator. Spin a magnet past a coil of wire and you produce electricity; add timing and a distributor, and that electricity becomes a spark at each cylinder at exactly the right moment.

The reason the magneto has survived since the early 1900s - technology that predates powered flight - is that it needs nothing from the rest of the airplane. No battery. No alternator. Kill the entire electrical system in flight and the engine keeps running, because the magnetos make their own power from the spinning of the engine itself.

That is genuinely elegant engineering. Every runup, when you check left mag and right mag, you are confirming two completely independent ignition systems, either one of which can fly the airplane home.

Why Replace Something So Reliable?

The magneto has one fundamental limitation: it fires the same way at every power setting and every altitude. The timing is fixed. A mechanic sets it with a timing light, and it never changes - whether you are at full power on a sea-level takeoff or leaned out at 11,000 feet. The spark is a compromise, tuned for the worst case and mediocre everywhere else.

It is also a mechanical device full of parts that wear: points, or in later units a coil, bearings, and a distributor gear. The FAA and manufacturers now call for many magnetos to be inspected internally every 500 hours, because when a magneto fails, it can fail in a way that fires at the wrong time - which is hard on your engine.

So the magneto is reliable, independent, and fundamentally dumb. That last trait is the opening for electronic ignition.

Experimental vs. Certified: Two Different Worlds

There are two separate worlds here, and they are easy to confuse.

In the experimental world - homebuilts and kit aircraft - full electronic ignition has been common for years. Companies like Electroair, the Lightspeed systems, and the self-powered P-mag units have been firing homebuilt engines with computers and coils for a long time.

The certified world moves at the speed of paperwork. A factory Cessna, Piper, or Bonanza must use parts approved by the FAA through a Supplemental Type Certificate (STC) before they can be legally installed. For decades, no one wanted to endure the pain of certifying a computer to replace a magneto on an average owner’s airplane.

How the SureFly Module Works

SureFly’s key design decision is what made certification realistic: it does not replace both magnetos. It replaces one. You keep a traditional magneto on one side, and the electronic unit goes where the other magneto used to live.

That means you keep the independent, self-generating, battery-optional backup the magneto has always provided. You are upgrading half of a redundant system while keeping the proven half - smart systems thinking that made both the certification argument and the ownership decision far easier.

On the electronic side, a computer inside the module reads engine speed and manifold pressure (a proxy for how hard the engine is working and how thin the air is) and moves the spark timing to match. At low power and high altitude, it can advance the spark, lighting the fire earlier for a more complete, more efficient burn - something a fixed magneto simply cannot do.

What Are the Real-World Benefits?

Owners running these systems report tangible gains:

• Fuel savings of roughly a gallon per hour, depending on how you fly.
• Easier starting, because the electronic unit delivers a hotter, better-timed spark at cranking speed than a barely-spinning magneto. Cold-morning starts get noticeably less dramatic.
• Lower maintenance, with no 500-hour internal inspection and no points to wear out. It is a sealed electronic box.

What Are the Trade-Offs Pilots Should Understand?

This is not a hype-free upgrade, and the caveats matter.

It needs electricity. The magneto’s superpower was that it needed nothing. The moment you put a computer in the ignition path, it depends on your electrical system. Good designs address this - SureFly’s module carries a small internal backup power source so a total electrical failure doesn’t instantly silence that side - but you have added a dependency the old iron never had. Know how that backup power works before you need it.

Aggressive timing can damage an engine. Advanced timing is a genuine benefit, but timing that is too aggressive is exactly how you cause detonation, the destructive hammering that occurs when the mixture lights off wrong. The entire safety case rests on the software and sensors getting it right, and on operating within the limits the STC was tested for. Follow the approved data - do not freelance.

The track record is younger. This is a computer bolted to a piston engine that vibrates, heats, and cools thousands of times per flight. The record so far is good and improving, but it is far shorter than the magneto’s 100-plus years. New technology earns trust by accumulating hours, and these systems are still doing that.

Why This Matters Beyond Your One Airplane

Walk the exhibit hangars at Oshkosh (EAA AirVenture, July 2026) and you can see the whole arc. In the experimental and kit world, electronic ignition, electronic fuel injection, and full-authority digital engine controls - the same kind of computer brain that has run automobiles since the 1980s - have been normal for years. In the certified world, that technology arrives one carefully approved STC at a time, magnetos first because they were the easiest beachhead.

The experimental category is general aviation’s research and development lab. Ideas get tried on homebuilts, rack up hours, mature, and the strongest ones eventually earn their way onto the certified fleet through the paperwork. The magneto replacement you can walk up and touch this week is a visible piece of that pipeline.

Who Is Building It?

SureFly, now part of Continental, is the name most owners associate with the certified single-side module. Electroair has its own STC path. And in the experimental world, Electroair, Lightspeed, and the P-mag community have been doing this for years - quietly teaching everyone else how it should work.

What’s the Honest Timeline?

Single-side electronic ignition on certified airplanes is here right now, with STCs covering a long and growing list of Lycoming and Continental engines.

Full dual electronic ignition - both sides computerized with no magneto at all - is coming more slowly. That is the point at which you finally give up the self-powered backup, and that is a much bigger conversation. Expect it to take years and many more accumulated hours before the fleet is comfortable.

Should You Make the Switch?

If you fly behind a certified engine and there is an approved STC for it, the single-side upgrade is one of the more genuinely sensible modernizations available: easier starts, better fuel burn, less scheduled maintenance, and a real magneto still standing by as your backstop.

Go in understanding the deal you are making. You have traded a little independence for a lot of intelligence - and you should know exactly how the backup power works before you ever need it.

Key Takeaways

• The SureFly module replaces one magneto, not both, preserving a self-powered magneto backup while adding computerized timing control.
• Benefits include roughly a gallon per hour in fuel savings, easier starting, and no 500-hour internal inspection.
• The main trade-off is a new dependency on electrical power; SureFly includes a small internal backup source.
• Electronic ignition reads engine speed and manifold pressure to advance timing for a more efficient burn - but overly aggressive timing risks detonation, so you must stay within the approved STC data.
• Single-side certified upgrades are available now (STCs for many Lycoming and Continental engines); full dual electronic ignition on certified aircraft is still years away.