Out Of The Pattern

You Can't Charm An Alternator Back To Life

Equipment failures are the bane of a pilot's existence. We plan for them, even practice our emergency procedures "in the unlikely event that" we encounter a problem. Aircraft owners (most of us) perform preventative maintenance to make sure our equipment doesn't quit in a pinch, and we blanket ourselves with back-up systems - just in case. Of all the solutions to an equipment failure, I like redundancy best. When my husband loses a yaw damper at 35,000 feet in the Boeing 727 he flies, he hardly knows it. A back-up yaw damper comes on-line to cover for the ailing one. His crew squawks the problem and switches airplanes at the next stop. No problem.

Last weekend a friend ferried a twin-engine Piper Seminole from Pennsylvania to Florida. The winter weather wasn't the best, but the trip was doable. She left Pennsylvania in the late afternoon, hoping to be home by midnight. She had an alternator failure somewhere over the mountains of western Virginia. So what. The Seminole, you see, has two alternators. She reduced the electrical load by turning off nonessential electrical equipment to avoid overloading the good alternator, and continued to her planned refueling stop. She decided to spend the night there because she didn't want to fly an ailing airplane in the weather, in the dark. It also gave her a chance to see whether she could get the broken alternator replaced.

Let's contrast my husband's and my friend's experiences with a couple of failures I've had recently. I fly an older model Cessna 210 and a Kitfox, a small, two-seat taildragger my husband and I built. Orlando International on a busy afternoon is no place for a small airplane with an equipment failure, but there I was. I'd just turned the 210 outbound after takeoff when I noticed the alternator had popped off-line. Perhaps the gear motor had sent out an electrical surge.

The Cessna has an alternate electrical bus, so I shut off the master switch and kicked on the alternate bus, which gives me a radio to talk to the Class B controller and a GPS to navigate with. It was daytime - and VFR - what more did I need? I let the system settle and concentrated on getting out of the Class B airspace, which took all of five minutes. Kissimmee Municipal, a Class D airport with services, was immediately below me if I needed to land. I sniffed for smoke - none.

Then, before the controller had time to fuss about seeing only my primary radar target on his screen (the alternate electrical bus does not power the transponder), I reset the systems, reduced the electrical load, and turned on master switch. The alternator came back on-line. I turned on everything slowly, waiting to discover the system that might be the culprit. No problems detected. Great! But 20 minutes later the battery voltage dropped again - no alternator.

There's a rule about systems. If an electrical circuit breaker kicks off and you reset it once and it stays, great. Maybe it was just a fluke. If it kicks off again after resetting, you've probably got a real problem. Halfway home, I was over the middle of Nowhere, Florida. It was a beautiful VFR afternoon, and I was squawking 1200, talking to no one. Who needs an electrical system now, anyway? I shut off the avionics master switch, then the master switch. The airplane hummed along. About 15 minutes later I hit the alternate bus long enough to announce myself on the multicom. I pumped down the landing gear by hand, saving the battery for the flaps. It was an uneventful landing, but still, I was grumpy and my arm was sore from all that pumping. Yeah, I was thankful for my back-up systems - the battery and my own brute strength (hand pumping the gear) - but true redundancy in the form of a second alternator would have been nice.

Perhaps I'm especially charmed, or maybe it's just my electric personality, because the next airplane I touched also lost its alternator. On my way home from an air show, I was climbing out in the Kitfox when I saw the ammeter needle falling. Not good. The Kitfox has an electronic ignition system and if that 6-volt motorcycle battery isn't feeding energy through it, the engine won't have a spark - and the world will get real quiet.

Kinda gets your attention, if you don't catch the gauge indication quite soon enough. Losing an alternator in this airplane constitutes a whole different level of emergency. Fortunately for me and my passenger, home was but minutes away. We made it with battery power to spare. If I have to choose between emergency procedures, back-up systems, and true redundancy in an airplane, I'll take redundancy any day. Twice the cost? Yes. But it's a small price to pay for peace of mind.