The International Cessna^® 170 Association

I was at the Arlington Fly-in yesterday,and was looking over the "win me" Luscombe that the Luscombe Foundation is gonna raffle off this year. It was very nice,had a C-90 engine with a B&C lightweight starter. It also had a very trick,trim little alternator. The guy who was in charge of the plane,who seemed pretty knowledgable, said it was a 30-amp unit made by B&C. Apparently it is for experimental use,but the Luscombe Foundation,who rebuilt this Luscombe, got a field approval to make it legal on a certificated airplane.
I looked on the B&C website,but couild only find a (I believe) 15-amp unit,which looked like the one on the Luscombe. This one probably isn't quite enough,but I'm sure a 30-amp unit would meet my electrical needs. And would probably come in at about a third or maybe a quarter of the weight of my 60-amp Cessna/Ford alternator.
Cool.
Eric

Do alternators put less of a load on the accessory gears than generators? I'm thinking that an alternator is lighter, but I don't know if the mechanical load of a 35 amp alternator is lower than a 35 amp generator.

Hopefully this makes sense.

Brian

I don't know, but I assume that the mechanical load would be the same,given the same output. In other words,the same amount of work being done. It may be that the alternator puts out it's 30 (orr whatever) amps at lower rpm than does the generator. Or vice versa.

Eric

I have the B & C 12-amp alternator on the C-85 in my '46 140 (...well, it's a little 170!) and couldn't be more pleased. It does come "on line" much sooner than the old 20-amp generator did...has no brushes and suggested "TBO" is 2,000 hours or at engine o'haul. And, it weighs only 4.25 lbs (Means that Donna can take along an extra pair of shoes! ) We received a field approval without any problem -- B & C supplies copies of others' 337s and plenty of engineering data to satisfy FAA tech reps. Now, the 30-amp wasn't ready for market when we bought the 12-amp -- it's almost the same weight, I understand, and would seem almost "perfect". We'd probably opt for the 30A now. In any event, B & C is known for quality products and this surely seems to be another one.