The International Cessna^® 170 Association

hilltop170 wrote:George-
What are you trying to say? That multiples are not a good idea or shouldn't be approved? If a multiple field approval is approved by the FAA, it is approved. Period. This one is approved. Why the disparaging remarks?

Mel told me the number of possible aircraft this mod would conceivibly be installed on is so low going thru the expense of an STC would never pay out. The multiple was an economical way to do it. Otherwise we might not even be able to get one at all these days with the shut-down of one-time field approvals.

I think any method that can be employed to obtain valid modifications for us GA folks should be embraced.

The multiple approval that started this discussion DID have design and installation data. I have a copy in my logs.

It's not that Mel has been the only one deemed sufficiently astute to install this modification, it's just that he is the only one that DID IT! If this mod needs to be removed to make a repair to the rudder, for instance, it can be reinstalled without going thru any re-approval. I don't understand the point you're trying to make.

No disparaging remarks were made, and I haven't criticized Mel or his mod. I only offered an explanation as to the FAA's previous view towards field approvals, and an explanation for their change of view.

Use of the term "Remove" implies the aircraft was returned to original status. In the example you used, Richard, the mod was not removed. It was maintained.

Yes, indeed, only Mel was deemed to have the necessary (astute) knowlege, skill, and understanding of his mod (sans additional documentation) to be authorized to perform the alteration. By definition that's why Mel is the only person so authorized on that particular multiple approval.

George-
It doesn't sound like we are disagreeing, just trying to make different points. May I suggest we discuss this further with beer?

I think G A Horn posted about Friction Plates acting like a clucth until they were overlubed.


Still have tailwheel questions. What are the Part Numbers for these friction plates?

Do these plates ever wear and get replaced?

I have seen machine manufacturers supply replacement parts that are not same quality as original parts because they were trying to live off parts instead of new unit machine sales. Has this occurred with any C 170 parts?

Regards

Items 3, PN 3207 (1 ea.) , item 4, PN 3234 (1 ea.) , and 7, PN 3206 (2 ea.), are all called "thrust washers", and in conjunction with compression springs, Item 5, PN 3233 (3 ea for a C-170... not the five in the illustration) , form a friction clutch.

When you disassemble your Scott 3200 tailwheel, there are some parts to perform maintenance on that are typically neglected.
Use these guides:
http://www.akbushwheel.com/CompleteTail ... embly.html
http://www.akbushwheel.com/images/graph ... 012407.jpg
This is where Spruce obtains their parts.

Remove and Replace 3 seals (2 on wheel (#32), one on bracket (#17)).
Most A&P's neglect to R&R the steel pin in the forks (#38 in picture, not listed in part list).
Many times, the pin is not worn, but many have been found well worn.
(The pin does not show up in the SCOTT or the Spruce diagrams referenced above.)

Secret to removing pin:
Do not drill out unless all else fails!!!
Drill thru pin (top to bottom) with smaller drill (size your pin punches or steel pin).
Work some grease into new hole in pin. Try using small wire to push grease into void under pin
Insert pin punch into hole (close diameter with small clearance).
Tap pin punch with hammer.
The majority of the time, the hydraulic ram pressure will eject the worn pin.

If your hole/pin is too tight, you will make it worse. If too lose, the grease will leak by.
Remember, you are trying to extract a steel pin from an aluminum housing.

N2504

This is the kind of information I am trying to search out.

I finally located part # 38 the small pin on the Bushwheel line drawing. Now as to the reason it is not listed in the parts list we will probably never know .
Oversight , maybe.

You say that this pin is often ignored and some times it is indeed worn.

Is there any factory publication that indentifies this part and definely states its function ?

Since it is a steel pin with a force fit into an aluminum casting I am thinking it must be important.