National Aeronca Association Bulletin Board

What exactly is the regulation regarding ski installation? My log book states (from several years ago, before I bought the Champ) a ski installation along with a 337, although not the exact pair that I have, at the present time.

I weighed my wheels and skis and they are within a pound of each other for each side so there's very little change in useful load ( Two pounds......I put that much extra clothes on during the winter). No change in CG, or so small it can't be measured. According to "Owner Maintenance" I am allowed to remove/install wheels/skis as long as "no computation of weight and balance is required". Guess I'm a bit confused as it seems I should be able to install the skis and make a log book entry and that's it......installing skis, ain't exactly brain surgery.

Doesn't make a lot of difference right now as the snow is almost all melted .

I can't download a PDF for 43.13 as our connections are too slow out here in the sticks.

Thanks,
Mike

Taken from AC 43.13:

81. Interchanging of Skis and Wheels
After the initial installation, removing the skis and reinstalling the wheels or vise versa may be considered a preventive maintenance operation when no weight-and-balance computation is involved.

Since ski's where once installed you can simply install the ski's and go, noting the previous ski install. Another way to skin the cat; make a new log entry noting the weight change is negligible and the ski's are listed in the TCDS as #203 (a). After that it only takes a log entry stating a swap from wheel to ski's and vise versa.

nkh

Mike,

I was going to ask you if you wanted a copy of 43:13 but
I have made an executive decision (thats really out of my league).
I'm going to send you AC43:13-2A Chapter 5. Ski Installations.
9 pages plus a couple other on Installation Details.
I'll put them in tomorrows mail.

Your welcome.

The orginal skis were Federal 1500's. The ones I have now are 1850's (both typed for Champs). I guess my question should have stated "Do I need to do another 337 for the 1850's?" Especially when the weights are so close. I'm inclined to agree with your last interpetation as the weight and CG change are negligible. I can't imagine why it would be necessary to do a 337, but stranger things have happened. Most people I know don't even bother to put the ski/wheel change in the logs. ..... On the other hand, I like to be 'legal' if I possibly can.

I kind of wish they'd take these "simple" airplanes and turn them over to 'owner maintenance'. Most ultralights and homebuilts are more complicated than Champs, Chiefs, J-3's etc.

Hoping for snow...... .........anyway!!

Thanks......Mike

Talked it over with the IA at dinner tonight and he agrees; No 337 needed. Bolt them on and make a log entry:

12/27/2005 Removed left and right wheels, installed Federal 1850 ski's
(TCDS #203 (e)) in accordance with AC 43.13 and Federal instln. dwg.
11R241 . Weight change negligible.____________________________

Thats how I'd do it, simple and legal.

nkh

Thanks Nathan. That's about how I wrote it up, other than I also have the ski serial numbers.
Mike