There have been a few hints on here that at least one of you wild and crazy pilots has put a set of desser 8.5 smoothies on their Cessna 180, or at least has seriously thought about it. If so would you be willing to share your experience and opinion. More importantly, a picture. I'm interest in the performance but also and probably more importantly, the cool factor. I just want to know if they look good and if there is some legal loop hole to try a pair of these on my beautiful bird.

My 8.5,s are just about done. Which 8.5 is the best one to replace them with. I am constantly filling mine back up with air.

Mission: fast and light landing on the usfs trips in the Idaho backcountry.

180lamb wrote:I just want to know if they look good and if there is some legal loop hole to try a pair of these on my beautiful bird.

Actually yes:

http://fadodge.com/images/pdf_files/FAA ... rcraft.pdf

Soooo, your looking for a pair of smoothed out 8:50's for the cool factor?

AKT

Change from the 8.50's to 26" Goodyear blimp tires. You won't loose any cruise speed, get more flotation and easy to get a field approval.
http://www.desser.com/Aircraft-Tires-an ... -6-PLY.asp


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I was very very tempted to go with them. My AME and I decided that we weren't sure if 4 plys were enough for a 180. So ended up with 8.50 airhawks. If more people start running smoothie 8.5 I will switch to. Just didn't feel like being a guinea pig.

The factory equipment list for my 1953 C180 lists both 600x6 6 ply and 800x6 4 ply MLG tires, so I would think that 850 4-plies are stout enough. But you do need some sort of approval for 850's. I have the North Sound Aviation (Jim Hayton) STC, it lists 850x6 6 ply tires (no brand name specified) so unfortunately the 4 ply 850 smoothies don't really qualify. There's also a Kenmore STC, not sure exactly how it reads, and there might be others yet.

Surprisingly no one has an STC to put the 26" GY blimpies on a 180, so it's a field approval show. They're noticeably larger than 850's but not quite as big as STC'd 26" BW's. Pretty heavy, plus kinda spendy also at about $750 each these days-- but a lot cheaper than the BW's. For my flying, the 850's do fine, plus they are a lot lighter and cheaper. I've always liked the Airtracs so that's probably what I'll get when my Desser recaps wear out. Or maybe just bootleg on a set of those 4-ply smoothies.

OK......

I'll be the Guinea pig. Tahoe is going to wish he could catch me and load his plane 20 lbs heavier(legally).

Pictures forthcoming.

Thanks for the help boys.

Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

It'll be interesting to see how well those tires hold up on a heavier aircraft, like the 180. Keep us posted.

MTV

Here's one mounted on a 180 sitting next to an unmounted 8.00x6.00.

Some initial thoughts (I don't have time on them):
They are "squishy" on a 180 due to the 4 ply.
They measure about 20.5" at 18 PSI.
With tire and tube they are about 11 lbs each.
Time will tell how they hold up, but they seem like a good compromise (for my mission).
(Note, these are on a non-flying project 180. Paperwork to be completed at a later date.)



Hope that helps, Matt

mtv wrote:Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

MTV

Wrong!


While the letter should help getting a field approval in itself it is NOT an approval!

Right in the letter it states you will need a 337.

Here is the process.

Print out the letter.
Have your mechanic fill out a 337 stating the changes and send it to the FSDO along with the copy of the letter.
Wait fort a field approval. (it might take a while).
If and when the 337 is returned and signed by the FAA install the tires and tubes.
Get an IA to sign off the 337 and make a logbook entry.

Also I agree with Barnstormer and Hotrod180 the 26" Goodyears are a good choice.
Bigger than the 8.50's and the rubber compound is tough! It wears really well!

Good luck

The linked letter approves 850x6 4 plies on original main gear wheels. On my 53 model 180, those were Goodyears. Strictly speaking, it does not approve them on aftermarket wheels, such as my Clevelands,
and also does not approve 850x6 6 ply tires.

Nit picking, I know, but isn't that what aviation regs are all about?

TangoFox wrote:

mtv wrote:Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

MTV

Wrong!


While the letter should help getting a field approval in itself it is NOT an approval!

Right in the letter it states you will need a 337.

Here is the process.

Print out the letter.
Have your mechanic fill out a 337 stating the changes and send it to the FSDO along with the copy of the letter.
Wait fort a field approval. (it might take a while).
If and when the 337 is returned and signed by the FAA install the tires and tubes.
Get an IA to sign off the 337 and make a logbook entry.

Also I agree with Barnstormer and Hotrod180 the 26" Goodyears are a good choice.
Bigger than the 8.50's and the rubber compound is tough! It wears really well!

Good luck

You are probably correct that in many districts it may take a field approval. A 337 does not necessarily imply a field approval, however. This letter constitutes approved data, as far as I know. And, yes, approved data still has to go through some "process".

As to the specifications of original wheels, I suppose in some districts that could be an issue. So, stick with the original wheels, and tires...... I know a few mechanics who are getting stuff done, largely because they're courageous enough to either make the request or just do it. A good mechanic will have developed a relationship with his/her PMI and that makes all the difference.

MTV

TangoFox wrote:

mtv wrote:Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

MTV

Wrong!


While the letter should help getting a field approval in itself it is NOT an approval!

Right in the letter it states you will need a 337.

Here is the process.

Print out the letter....

Whoa..... Lot of excitement there.

Actually, MTV IS right. Yes, you need to complete a 337, but NO field approval is needed. The first letter from Dave Byer is the approved data, and the Atlee letter from the FISDO confirms it. Just cite the letter in the 337 and move on...

bigrenna wrote:

TangoFox wrote:

mtv wrote:Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

MTV

Wrong!


While the letter should help getting a field approval in itself it is NOT an approval!

Right in the letter it states you will need a 337. Hour Year

Here is the process.

Print out the letter....

Whoa..... Lot of excitement there.

Actually, MTV IS right. Yes, you need to complete a 337, but NO field approval is needed. The first letter from Dave Byer is the approved data, and the Atlee letter from the FISDO confirms it. Just cite the letter in the 337 and move on...

Sorry, but Tango Fox is right. The letter is simply just approved data to use for the field approval. That's the problem with these forums sometimes you get conflicting information. As far as anybody who plans on using this letter without submitting a 337 for Field Approval should call their local PMI and get their EXPERT opinion before mounting a tire that's not on the TCDS for their aircraft.

C185D wrote:Sorry, but Tango Fox is right. The letter is simply just approved data to use for the field approval. That's the problem with these forums sometimes you get conflicting information. As far as anybody who plans on using this letter without submitting a 337 for Field Approval should call their local PMI and get their EXPERT opinion before mounting a tire that's not on the TCDS for their aircraft.

I totally agree (and noted earlier) that talking to your friendly local mechanic and his/her PMI is always a good idea. But, if your standard for what requires a field approval is what tires are listed in the TCDS for your airplane, you may want to take a good look at the TCDS for the Cessna 180.....if that's your standard, tires aren't approved, apparently. As I noted, this is going to vary somewhat by district. Nevertheless, a field approval SHOULD be a no brainer for approved data.

Now, please don't attack me for suggesting that FAA types have no brains....wasn't my intent. Just take the dang letter to your mechanic, and let him or her decide how to proceed. I'd bet that 99% of mechanics in this world have never heard of that letter.

MTV

From the linked FAA -> Atlee Dodge letter:
"...as outlined in a letter from former FAA ACO aeronautical engineer, Dave Byer, to Mr Jack Peck of Alaska Aeronautical Industries, dated in 1961."
I'd say to get the full scoop on this issue, "approval" vs "accepted data" or whatever, you'd need to read the original letter referenced here. Anyone have it?

Minus the legal hoops would any of you have ANY problem putting these 8.5 smoothies on your bird.

If someone gave you a pair with the legal paper work, would you put them on. I'm not talking cool factor or rolling over big rocks or mission specific issues. I want to know if this crowd thinks they are safe. Can they handle the load, everyday wear on grass asphalt etc....,on a 180.

Regulation, opinion, experience and reality. The truth is usually somewhere in the middle. Maybe these just aren't stout enough for the 180. Or maybe they are a great economical tire that weighs less, won't throw rocks on my horizontal stab or slow me down. I just don't know. But I'm really curious.

bigrenna wrote:

TangoFox wrote:

mtv wrote:Here's your approval basis for 8.50 tires on a 180/185: http://www.fadodge.com/images/pdf_files ... rcraft.pdf

Copy that letter, take it to your mechanic....minor alteration. Based on a Regional Engineer's opinion....should be pure gold.

MTV

Wrong!


While the letter should help getting a field approval in itself it is NOT an approval!

Right in the letter it states you will need a 337.

Here is the process.

Print out the letter....

Whoa..... Lot of excitement there.

Actually, MTV IS right. Yes, you need to complete a 337, but NO field approval is needed. The first letter from Dave Byer is the approved data, and the Atlee letter from the FISDO confirms it. Just cite the letter in the 337 and move on...

Apparently no one has a copy of the 1961 Letter?

There is always confusion on "acceptable" and "approved" data.

In the letter posted on the FA Dodge site it states that the installation is "acceptable".
The FAA definition of acceptable data means that the FAA inspector can "field approve" the installation based on the Data.
After the FAA "field approves" with emphasis on "approve" then the data becomes "Approved Data" by FAA for that particular aircraft only!

If data is already "approved" like an STC. then an IA can just sign off the 337 without any signature required from the FAA.

Now if the original letter reads as "approved" not "acceptable" then we may have a different ball game.
If this happened to be the case you would need to attach a copy of the 1961 letter to the 337 for filing with the registry anyway.
I am going by the reaffirmation letter posted.

Hope this helps.

Yes, I would say they're safe. Like I pointed out, 4 ply 800's were a factory option for my 53 180. 4 ply 850's should be plenty good, and maybe cushier for a given air pressure than a 6 ply tire.
The only "if" in my mind is how would they hold up?
Lighter weight than comparable 850's to me means less rubber.
But at $450 a pair (vs $478 for air tracs) it'd be worthwhile to try them.
Go for it!

180lamb wrote:Minus the legal hoops would any of you have ANY problem putting these 8.5 smoothies on your bird.

If someone gave you a pair with the legal paper work, would you put them on. I'm not talking cool factor or rolling over big rocks or mission specific issues. I want to know if this crowd thinks they are safe. Can they handle the load, everyday wear on grass asphalt etc....,on a 180.

Regulation, opinion, experience and reality. The truth is usually somewhere in the middle. Maybe these just aren't stout enough for the 180. Or maybe they are a great economical tire that weighs less, won't throw rocks on my horizontal stab or slow me down. I just don't know. But I'm really curious.

They state max load for the tires is 1600lbs each so anything weighing less than 3200 you should be good to go.

If you were operating on sharp rocks etc I would personally want 6 ply.

Grass and asphalt should be just fine.

I think they would make a good tire for your 180 in most situations.

Let us know how you like them.