Federal C2200 Hydraulic Skis and 8.50 x 6 tires

I recently got a 337 approval for 8.50 x 6 tires on my PA18, and with the superb technical help of Darrel Starr was able to mount the tires...really like them!

Winter is now here, and so is the time to do some ski flying. I checked with the AI who did the 337 for the tires, and he felt that as long as they did not interfere with the movement of the Federal C2200 hydraulic skis no further approvals are needed.

So...three of us installed the skis, jacked up the supercub and checked out the movement and there were no clearance problems noted...worked smooth as silk. The 8.50's sat right where the original tires sat when the skis were in the retracted position. I haven't flown the aircraft, pending signoff on the logbook entry by the A&P. I have a weight and balance sheet for the PA18 with and without the skis attached, will make the necessary changes for that.

I would just like some reassurance from those of you who have had the 8.50s in use with the C2200 skis. Tell me I will be fine, please

Many thanks.

Randy

If your IA is willing to sign it off... I wouldn't be askin.. nor postin it here!

I agree with Irishfield. My 30 years in the FAA has learned me one thing. If you don't want to know the answer.... don't ask the question. Or.. It's better to beg for forgiveness than ask for permission.

I seem to recall there is a little button on a post called "delete".....

Randy,

Look at the ski STC. Call Wipline, the holder of the STC. I'm betting that will provide the answer. If it's what I think it is, don't go there, even if a mechanic signs it off. I've been there on a different deal, and wound up hiring a lawyer to defend my IA. Call Wip. They'll give you the straight scoop.

In any case, MAKE ABSOLUTELY CERTAIN that you have a Weight and Balance for both "wheels down" and "skis down", since the arm of the skis changes substantially. One W/B doesn't make it for these skis.

MTV

Wip does include the 8.50 x 6 tire as approved for the C2200 skis on PA18s. The following picture was taken from Wipaire Installation Drwg 11G1363.
Darrel

Thanks, fellas, for your comments. Darrel did some checking and the 8.50's are approved. Mike, I will make sure the W&B is done with skis up and down.

Randy

Good deal, thanks Darrel

MTV

With this drawing do we need a longer arm for the 8-50-6 tires or are they all the same ??

C-FIJK said:

With this drawing do we need a longer arm for the 8-50-6 tires or are they all the same ??

Click to expand...

I was wondering the same thing. I just got a set of 3600s for the Skywagon and understood the long arms are suitable for 8x50s. Although not all 8x50s are created equal...

3600 long arms are 10” CTC of the axles. Great with 850s.