Hello,

I've just made a start on building a 1/3 aeronca champ from plans by John Marquette. It's a large plane but quite light at around 30lbs. On the drawing the recommended engine range is 40-50cc, I have a Thor 45cc petrol so seems ideal and flying style will be very scale. Reading on web is quite confusing however as folk go on about 60 and even 80cc engine's for it which well above what's stated on the drawing. The original full size only had 65bhp later going up to about 110bhp so it was never over powered. As I have an engine for it I'm quite reluctant to spend a lot of money on a new engine based on unverified suggestions. There must be quite a few of these now built, can anyone offer some advice based on real models? Thanks, Scott.

Whippy, I have a semi-scale Champ that has a wing span of 97 inches a wing area of 1200 square inches and it weighs 21 pounds. it is over powered with a 40cc engine. Dan.

Hello Dan, thanks your model is closer to 1/4 scale, same size as my T240. That's quite an engine for that plane, I've got a 1.35 glow in the T240 and it can almost prop hang, it's only meant to have a 0.60 - 0.90.

You can't compare wingspans and call dis-similar models the same, Variations in construction can make a model weigh more than another of a similar span.

I've seen this model, and I agree with the 60-80cc suggestions.

I have to say the model is grossly overweight and some of the material selections definitely born in the 80's. Amusingly things like the ribs are built up to save weight and then a slab of a bulkhead from 1 & 1/4 inches thick ply with no lightening holes completely defeating the whole effort. I reckon I can lighten this thing enormously with lite ply, GRP & carbon and getting parts laser cut so I can build in lightening holes on a lot of the parts.

1/2" thick firewalls were standard at the time, I remember reading that requirement in the Quadra 50 manual.

I have a 1/4th scale Nosen Champ. It was a barn find with a 90 in it. I tried a 26CC wacker engine, too weak. I now use a CRRC 40 kit engine. Works great. IMHO making it "fly scale" is poor advice. You can always pull the throttle back to "fly scale". IF you have insufficient engine you can not do much about it.

The original airplane was pretty sedate. I would not emoulate it. They don't climb out very fast. In a RC you can not monitor your airspeed as well so stalling is easier to do.

I remember seeing a John Marquette designed Aeronca at Joe Nall probably close to 15 years ago . Don't know why it caught my eye but it was a well constructed plane. It flew on a Zenoah G45 and flew well. I suspect you will need nose weight up front as the nose did appear short . That might be why there is such a thick firewall , to help ballast the plane .

1/4 scale Champ Bud Nosen used a Quadra 42 the weight balanced it out perfectly and I flew it scale at 1/3 to 1/2 throttle. Its very nice to have a little extra motor when you need it to get you out of trouble. If your flying at the smaller engines limit and you need that extra power to pull you out of trouble you may be out of luck. Throttle management is everything. You will have to end up adding lots of weight with the smaller motor why not make it usable weight by installing a bigger motor.

Dennis