Weight gain

[herman pahls 9]

Airplanes are like most humans; they gain weight with age.

I was shocked by how much weight my Model 1 gained in 17 years from the original 532 with single ignition and A-box.

Just a few pounds here and there.

582 with dual ignition, C-box, RK clutch, IFA prop,HACman mixture control, cabin heater and ducting, Odyssey battery left over from the Jabiru, bigger battery cables as need for the Jabiru, bigger tailwheel, matco brakes versus the original go kart brakes, radios and antennas, fuel flow meter, EIS, tools and a few spare parts, bigger than original tires and I am going bigger yet, 3/4 to 1 inch lift struts, plastic lift strut fairings, water logging?,

What started out as a marginal 2 seater due to 950# gross weight and my 200#'s has turned into a single seater unless my wife fly's with me which she doesnt very often.

I am considering going to a 80 HP 912.

I have seen posts that say the 912 will only add 35 pounds over a 582.

Is that realistic?

Besides getting the battery moved aft for weight and balance it seems like one builder installed larger tail feathers on his shorter fuselage Kitfox with a 912.

Opinions, facts and ideas would be appreciated .

Thanks Herman

[C5Engineer 1170]

Herman that's a pretty big can o worms but obviously it can be done. I'm assuming you've already contacted that guy on the other forum who has Dan Denney's original Mod 1 with a 912 on it? I looked at it during the Factory Fly-in. Besides that funny looking stick with a wheel on the end of it that he put on the front it was a nice looking airplane.

I have an almost complete MKIV kit that someday I want to stretch the fuse and put a 912 on it. I think one of these earlier models with a STOL wing would be amazing with the 912UL on it.

My airplane went from 484lbs with a 532 according to the original W&B to 535. I think the A&P that did my wings went waayyy overkill on the silver probably adding some unnecessary weight. 85% of the time I am light and out dinking around but during the other 15% of the time when I'm at gross flying to Idaho with a guy in a 100HP Rans who literally flies circles around me the extra HP would sure be nice!

[efil 01 74]

Airplanes are like most humans; they gain weight with age.

I was shocked by how much weight my Model 1 gained in 17 years from the original 532 with single ignition and A-box.

Just a few pounds here and there.

582 with dual ignition, C-box, RK clutch, IFA prop,HACman mixture control, cabin heater and ducting, Odyssey battery left over from the Jabiru, bigger battery cables as need for the Jabiru, bigger tailwheel, matco brakes versus the original go kart brakes, radios and antennas, fuel flow meter, EIS, tools and a few spare parts, bigger than original tires and I am going bigger yet, 3/4 to 1 inch lift struts, plastic lift strut fairings, water logging?,

What started out as a marginal 2 seater due to 950# gross weight and my 200#'s has turned into a single seater unless my wife fly's with me which she doesnt very often.

I am considering going to a 80 HP 912.

I have seen posts that say the 912 will only add 35 pounds over a 582.

Is that realistic?

Besides getting the battery moved aft for weight and balance it seems like one builder installed larger tail feathers on his shorter fuselage Kitfox with a 912.

Opinions, facts and ideas would be appreciated .

Thanks Herman

15 hp of gain against weihgt, building issues and money, may be sell the avid + money for 912 equals good used 2 seater 912 ultralight plane.

[EDMO 1078]

Besides getting the battery moved aft for weight and balance it seems like one builder installed larger tail feathers on his shorter fuselage Kitfox with a 912.

Opinions, facts and ideas would be appreciated .

Thanks Herman

If you read the Kitfox Histories, you will see that the early ones did not have enough tailfeathers. I believe the same is true for the Avids. As models progressed, the tails kept getting larger. I had a notebook filled with tail calculations until my mind went to mush! He was correct in enlarging the tail - A LOT! Mine was enlarged - a lot. I could furnish the formula from Darrol Stintons Book, The Design of the Aeroplane, the best design book I have ever read, but then you might get the room ahead of me in the "Designers Mental Ward"!!! Best thing is to just go with the measurements for the later models, and go flying.

The Rans is a nice airplane - most comfortable seats I have sat in.

ED in MO

Edited 19 Apr 2012 by akflyer
fixed to show reply outside quoted box