Does anyone have an example of a legal installation of 8.50's x6 or Goodyear 26" on a 170? I have a A model with Cleveland wheels and know that guys run them all the time especially in Alaska. Just looking for an approved 337. Thanks

I've got 337s of both on a 170B. They're already posted on this forum if you do a search. I think I also cc'd Zane, so they could be in the knowledge base here as well.

*Edit* Scroll down this thread for the Goodyear 337.

-DP

I actually might have one in the paper archives I inherited from Wannabe. I will look tomorrow.

Fortunately its now legal to run 8.5x6 on the C170, C180, C182 and C185 so no worries there.

You can download the FAA letter here: http://www.cessna170.org/forums/viewtop ... 24&t=10561

IMHO that letter can serve as "accepted data" and the basis for a field approval. Since you have to do a 337 anyway, I would go that extra step and get box 3 signed off (aka a "field approval"). The FAA inspector doesn't charge for that, & you're gonna have to pay your IA to do the 337 anyway.
IMHO a blanket across-the-board approval for 850's would require that they be included on the TCDS, or that an FAA policy letter be isseud from Oklahoma City, similar to the one issued for shoulder harness installations.
Plus, if you want to nitpick.... read the linked letter to Atlee Dodge, reference is made to 850x6 FOUR PLY tires installed on STOCK main landing gear wheels. The lightest 850's I've seen are 6 ply, and I haven't seen a set of stock wheels (Goodyears) on a C170 in many years.

Thanks for the Goodyears 337. I did a search, but couldn't find the example of the 337 for the 8.50's. Anybody have an example to share or can you point me to the right thread?

Thanks,

I've got the 8.50 337 too. Give me the weekend to dig it out and post it.

-DP

This is in response to hotrod150's post regarding the 8.50 authorization letter, it is not a reply to him but is for the consideration of the group. I believe that in the last few years we have seen a change philosophy from one of intent to one of requiring specific permission. When the original letter was written in 1961 it would have been the norm to read "4 PLY" tires and think of that as the minimum ply rating to have the required weight carrying capacity. Like wise most would have felt that a STC'd replacement for a "STOCK" wheel would have been at the least the equivalent of a stock wheel. Now days I am not sure that ALL FAA Inspectors would feel the same, and a field approval may not be guaranteed without the help of a DER. I do know that the Type Certificate for the 170B allows for 8.00x6 4ply tires with the originally installed Goodyear wheels and that I had no concerns with installing 8.00x6 6ply tires as a minor alteration on the double puck Cleveland wheels I had installed under the Atlee Dodge STC on an aircraft I owned. It is to bad that this has happened. Just an observation and an opinion of one A&P IA.

Tim

I went through my binder of 337's the other night and saw 3 sets: 29" bushwheels, 8.00x6, and 8.50x6.

They were all Approved by IA, which I assume means there's an STC standing behind the 337. None were true "field approvals."

Hey,i chased this for a long time as i understand there is no STC,S for 26 GY ON A 170 A OR B MODELS i have read from this [bcfp] site of two guys that might have a lengthy amount of paper to have a 337? the feds are not letting lose the paper. i ended up being legal with ABW's expensive but they come with paper. i fly out of D space with the faa office in my face...........i might add this thought after the ABW are old and ugly i might go back to GY's because i have the paper for big tires? need more 252-288-4595 i enjoy my 170 very much, they are dated and need improvement so i will continue to do so after all it is my plane and my ass.
cheers