8.50 tires with a Canadian 337

[8434]

Hi All!

I can't quite wrap my head around how to legally put 8.50 tires on my Canadian registered C-140. I have found the 337 paperwork as part of another thread however I don't believe that would be accepted in Canada. I have found that we canucks have a "Major Repair or Major Modification Report" form that looks remarkably similar to the 337 form. So here goes the question:

If my Mechanic and I fill out the "Major Repair or Major Modification Report" and submit it to Transport Canada, how do I know it will be accepted?

The Form requires the work to be "accomplished" prior to submitting it, so is the paperwork just to let TC know what was done and the responsibility lies with my mechanic?

Any other Canadians with 8.50 that would care to point me in the right direction? If your worried about TC spies then email me. Scouts honor I'm not a TC inspector fishing.

burrowsDOTmarshallATgmailDOTcom

Thanks for your help.
Marshall

[6643]

The Form requires the work to be "accomplished" prior to submitting it, so is the paperwork just to let TC know what was done and the responsibility lies with my mechanic?

Don't know about Canada, but, here is the States I would fill out the form and bring it and all my supporting data (your approved 337, for example), to my PMI and ask "will you sign off on this if I submit it?" I suspect your form also requires approved data (as does ours), so ask first.

If my Mechanic and I fill out the "Major Repair or Major Modification Report" and submit it to Transport Canada, how do I know it will be accepted?

Tarot cards?

[5115]

Marshall,
The Major Repair won't go thru at Transport Canada. We need an STC in Canada for anything that is not in the TCDS A768. That is the normal procedure. If not the LSTC exists...but you may not want to go there $$$$
Bushwheels (the 26inches) have an STC for the C140, I have that information somewhere if you are interested. I know 26in are not the same price as 8.5 and may also require double-caliper brakes (but that I'm not 100% sure).

If you know someone at your local Transport Canada office that has field experience (I mean maintaining small airplanes and repairing them) and if you arrive very well documented for the 8.5, he may accept to file that major repair form against your registration.....but that is the challenge.

Good luck

[5115]

If you go here: https://www.airframesalaska.com/v/vspfi ... %20AML.pdf
you will see the list of supported models. The 120 and 10 are there for the 26 and 29 inches tundra. I have not checked the other sizes.

[5422]

Single puck brakes work just fine with those Bushwheels (Ours has 29”). In the installation paperwork you have to do a static full power run up to make sure brakes keep plane from moving. Those 26” tires are not much bigger than the 8.50x6.00 tires. I think they come in a heavy tread version that would take pavement wear a bit better.

[8474]

Just wondering why you want an 8.50 as opposed to an 800 ? From what I can gather an 8.50 is about 21 inches and an 8.00 is around 18 inches. The 800 is approved and I believe a bit lighter than an 8.50 so an easy install.

I think for me I would either accept the slightly smaller size of the 800 or go for the Bushwheels 26 inch and avoid all the hassles of trying to get approvals.

[8434]

My rationale for the 8.50 is they are a good compromise. Looking at the tundra tires as an option I felt like putting 26 or 29 on was overkill, I have a C-90 so it's not like I'm going into crazy places. The Aero Classic 8.50 are light and big and don't have tread so they look like they will handle gravel well. They are pretty cheap which helps. As for 8.00s, they are an option of course. I guess I'm just curious about the process in place here in Canada to make modifications. I'm new to owning an aircraft and curious about how the STC, 337, Major Mod Report etc actually works. Tires seems like a good place to start as there are examples of bigger tire modifications and I already have the Cleveland Wheels and brakes.

To 5115, A rhetorical question: what is the purpose of Transport Canada having the Major Modification report available if they rarely accept it? The US seems to use the 337 process quite well and we seem to always copy them.

Thanks for the info, perhaps I'll poke around at the STC process. I sit in front of a computer all day anyway and know a few eccentric AME's that might be willing to help.

Marshall

[6643]

Just to keep things in perspective, the 337 is not a process here; it is a form, used to record major repairs and major modifications. Each of these must be accompanied by approved data. An A&P can sign off the work and an IA must inspect the work and approve the AC for return to service. A field approval is one type of approved data, and the one most often referred to when someone says "I did it on a 337." However, STC'd modifications also must be recorded with a form 337. The 8.00 tires, since they're listed on the Aircraft Specification, are a minor modification and can be done on a log book entry. The ABW wheels and tires are covered by STC, which is approved data, so no further approval is necessary beyond the signatures on the 337 of the A&P doing the work and the IA returning it to service.

[5115]

To 5115, A rhetorical question: what is the purpose of Transport Canada having the Major Modification report available if they rarely accept it? The US seems to use the 337 process quite well and we seem to always copy them.
Marshall

Marshall,
The Major Repair form is used in Canada, the name says it, when there is a major repair. Like replacing a surface that was bent following a hard landing and requires some metal and rivet job. Or even if there is no incident, something like redoing the covering on the wing because it is not in good shape anymore, etc. The Major Repair is sent to Transport Canada.
For all the other stuff that has an STC that exist, like the Spin-on oil filters, the bushwheels, cowling latches, MOGAS STC, etc, the AME will do a technical and logbook entry and the STC paperwork will be attached to it. To my knowledge, I don't think that we have to file a Major Repair form to Transport Canada on top of the STC paperwork. (Like what they do with a 337 and STC in USA as per John's comment)

But I'm sure that with some small digging into the TC website, you should be able to find when and for what a Major Repair form is required.

Happy flying!
Martin (Montreal)

[6643]

So, you don't have a Canadian form to record a Major Alteration?