Archive for February, 2013

Debonair Sweeps: A Bigger, Better Alternator

Tuesday, February 5th, 2013

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National AirParts’ new 70-amp alternator (right) next to the old 55-amp unit

 

I’m told that the first Debonairs–the 1960 models–came with 35-ampere/hour Bendix generators. That’s not much of a power output.  There are stories out there telling of lights dimming at idle power, and ammeters showing discharges when all electrical equipment is turned on. So next up was a 55-amp generator. That still didn’t provide a large enough volume of steady electrical power.

Our/your Debonair began life with the 35-amp generator, but that was swapped out for a 55-amp Alcor alternator according to the logbooks. That was a start in the right direction.

But 55 amps isn’t nearly enough for the basically all-electric panel being installed at Santa Fe Aero Services. “We need 70 amps,” said V-P and General Manager Pat Horgan.

Thus began my search for a Supplemental Type Certificate (STC) holder that could provide us/you with this sort of power rating.

National AirParts, of Deland, Florida (www.nationalairparts.com)  filled the bill with its popular STC that allows us to move up to 70-amp-land. National’s Al Petrone says he can even fix you up with a 100-amp alternator if need be. Thanks very much, Al.

National has a lot of alternator STCs covering a wide range of airplanes. Check their website for details and plenty of info.

And remember that bad old alternator bracket–the one that broke, and that I reported on last time? Well, Wentworth Aircraft’s replacement bracket (see my previous blog) fit the new alternator, and the whole works will soon be installed. Along with beefier wiring and a circuit breaker designed to the new limits.

Debonair Sweeps: Bracket Attack

Monday, February 4th, 2013

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The offending alternator bracket. Note the two breaks.

 

Where do you find a replacement alternator bracket for a 50-year-old airplane? Probably not from the manufacturer, which long ago stopped making replacement parts for airplanes that old. No, you have to check the salvage yards.

In the Debonair Sweepstakes’ case, we sought out Wentworth Aircraft Inc. (www.wentworthaircraft.com), the Minnesota-based supplier of a huge array of aircraft parts. We’ve used Wenworth several times in the past, when older sweepstakes airplanes needed new latches, doors, and other airplane parts both large and small.

Here’s the background info. On a flight out of Wichita’s Colonel James Jabara Airport, the Deb’s landing gear wouldn’t retract. So it was back to the airport and into the shop for some diagnostic work. Up on jacks and fed by a power cart the gear–of course!–functioned perfectly. And they continued to work at fuel stops on the subsequent legs to the avionics shop, Santa Fe Aero Services.

But once in the shop for its massive avionics upgrade, technicians got a good look under the hood. What they found was an alternator bracket that had broken in two places. This helped cause the gear non-retraction issue by failing to put out its rated power (55 amp/hours) and thus depriving the gear motor of the juice it needed.

There wasn’t much of a search for a serviceable bracket. Remembering Wentworth from earlier sweeps restorations, your truly called them first. I got a Wentworth service rep–Dave–on the phone, gave him the part number, and sent him a photo (see above) of the failed part. He began digging and called back with the good news: Part found!

It’s proof once more of the value of salvage yards (please don’t call them ‘junk yards’) to owners of older airplanes. Wentworth in particular has scads of reasonably-priced components that can be so essential in keeping GA’s aging fleet in the air.