Technology: It's electronic

Just about every aircraft piston engine is burdened with two magnetos, anachronistic holdovers from a bygone era. These mechanically complex, failure-prone relics are inherently inefficient because of their fixed timing. Mags fire at the same point in the combustion cycle regardless of the amount of fuel the engine is burning, the quantity of air it’s breathing, or the density altitude at which it’s flying.

Modern electronic ignitions (EIs)—such as those that have given cars across-the-board gains in power, fuel efficiency, and reliability—should be able to do even more in aircraft because their variable timing kicks in every time an aircraft climbs or descends. EIs can reduce fuel consumption, eliminate the need for 500-hour magneto servicing, and use inexpensive automotive spark plugs that produce hotter, longer-lasting sparks than the aviation variety.

Magnetos have been allowed to hang around all these years for one reason: They don’t rely on power from the aircraft electrical system. If an aircraft battery or alternator dies, or a pilot turns off the electrical master switch in flight, magnetos don’t care. They keep on firing. This critical feature has been enough to outweigh EI advantages; but not anymore.

A new generation of EIs that contain internal alternators has been developed—and they, too, can run without aircraft electricity.

“Magnetos can run without external power, and so can we,” said Brad Dement, founder of E-Mag Inc., a Texas firm that has built and sold more than 4,000 self-powering electronic ignitions for Experimental and Light Sport aircraft. “That’s been their sole claim to fame for decades, but it’s not going to be good enough anymore.”

E-Mag currently makes EIs for four-cylinder engines only, but the company plans to start shipping six-cylinder versions this year. Manufacturers have shown that EIs typically reduce fuel burn up to 15 percent, a savings of about 2.5 gallons per hour on a 260-horsepower engine.

Dement said the company also will pursue full FAA certification for a dual EI installation in Standard-category airplanes. “We’re going forward with it,” he said. “We’ve been encouraged by the FAA’s response so far.”

Light Speed Engineering, a California company, pioneered EI installations in Experimental airplanes beginning in
1986; they are standard equipment in Carbon Cubs, the best-selling Light Sport aircraft on the market. European regulators have approved Lightspeed’s system for use in both helicopters and fixed-wing aircraft.

Klaus Savier, the record-setting pilot who designed the Lightspeed system, said the company’s Plasma ignition systems increase range up to 20 percent over mechanical magnetos. “The advantages [of EIs] over magnetos have been clear for a very long time,” he said. “The aviation industry is finally recognizing that any electronic ignition is better than any magneto.”

Electroair, a Michigan company, has the only EI system the FAA has approved for Standard-category aircraft, and it replaces one magneto, not both. (The Electroair system is installed on the AOPA 2017 Sweepstakes Ascend 172, see page 36.) The Electroair system requires ship’s power, and it sells dual EIs for Experimental aircraft with battery backups.

I recently had the E-Mag system installed on the Lycoming IO-320 in my airplane, and the results were immediate and obvious.

The engine starts easier and cruises lean of peak EGT with reduced fuel consumption. By the time the engine reaches its 2,000-hour TBO, the fuel savings of one gallon per hour will have paid for the upgrade several times over. Eliminating periodic magneto servicing makes EIs an even better value.

I considered installing one EI and keeping a single magneto, and there are advantages to this approach. First,
you get about 75 percent of the fuel-efficiency benefit from a single EI. (The EI timing advances with altitude, so it typically fires before the magneto.) Second, if an aircraft is ever stuck on the ground with a dead battery, an impulse magneto would allow old-fashioned hand-propping the engine.

That’s not an option with EIs.

But I went with two EIs because the idea of being finished with mags (and aircraft spark plugs and ignition harnesses) permanently was too good to pass up. Also, my remaining magneto was due for an $800 servicing, and that was more than half the cost of a new electronic ignition ($1,395).

Hopefully, more EIs will gain FAA approval. And regardless of whether that approval comes in the form of STCs or full certification, the benefits in terms of fuel efficiency, reliability, and cost are too great to ignore.

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