The International Cessna^® 170 Association

Well, you apparently don't read my posts carefully. I would respecfully note that, in all cases of replacing aircraft parts, I have consulted with my friendly local IA, and in most of those cases, I've also consulted with my friendly local FSDO Maintenance inspector. There are logbook entries on all these things, complete with signatures. In some cases, I have also appended letters from my FSDO guy, giving his interpretation as well.

And, I didn't even have to buy them lunch. See, they're paid to make these decisions, not me. I take their advice.

I simply posted their advice, and the logic upon which they told me it was based.

Your post said that parts must be identical to be used for replacement. That is not universally true. They must be equal to or better than, not identical. There is no requirement for parts to be identical.

Note that there are many aircraft parts in use today, which are definitely NOT identical to the original. An example is the many Super Cub fuselages (YES, fuselages!!) that are now available on the aftermarket. They are not "identical" by any means, and most are also not stc'd. They are a pma'd replacement part. There are additional cross braces, and many other modifications. Some of these are indeed stc'd, such as the wider fuselages, but there are some floating around that are just plain old replacement parts, and not even close to the original.

How about Millenium cylinders? Are they identical? Are they stc'd? I actually don't know if they are stc'd or not, but I'm betting theyre not. They are certainly not identical, but equal or better than.

Anyway, you've made your point, which is apparently never, ever improve your airplane, because the manufacturer made it perfect from the git go.

I don't happen to agree with that philosophy, and neither does the FAA.

There are lots of ways to legally modify your airplane, and some of them are indeed "minor alterations". Says so in the FAR's even.

What's what, I leave up to the professionals, which I aint', at least not in the maintenance side. But I've got some great people to work with here, and I trust them, and their opinions. That's what they're paid for and they do it well.

Mike

To the contrary, Mike, I read your post quite carefully (including the one about how legal you thought it might be to install a Pratt and Whitney radial on a 170 because it's an aircraft part.)
But, Apparently you didn't read my reply. I didn't say all aircraft parts have to be identical. I spoke about a specific part, the compression springs in question. Any "improved" or "equal to or better" springs must still meet the original part's design, intent, characteristics, strength, etc. etc. in order ot be "equal to or better". Compression springs in lieu of tension springs are NOT equal to or better in that sense. They are different. In several ways. And not necessarily better, except in certain applications.
To be legally installed on a 170 they still must have a basis of approval. I've already explained that. And I've already noted that your mechanic (whom you've said signed off on it) is the person assuming that responsibility. I take no issue with that. I take issue with the logic that you espouse stating that because some device says it's an "aircraft" part you believe it can be installed in any airplane.
If you don't know the answer to your questions then you shouldn't publish made-up or hopeful answers without investigation. (Millenium cylinders are PMA'd replacements for the specific engines stated by their approval paperwork. They are NOT held by the FAA to be better than originals...only marketed by their mfr to be so.) Using the logic you (or your mechanic) promoted earlier, the Millenium cylinders would be OK to use on the Pratt and Whitney radial engines you mentioned earlier.
There are only so many hours in the day, and insufficent time/inclination to teach such basics (which I'm quite certain you already have the capacity to figure out on your own.) Let's not let this degenerate into a personal he said/she said. We can all read.
Bottom line: just because it says "aircraft" on it ...doesn't make it legal to install on YOUR aircraft. It needs a basis of approval other than the word "aircraft".
(And don't try to put words in my mouth. If I'd wanted to say not to improve aircraft, I'd know how to say that. Sarcastic sniping doesn't make promotion of wrongful maintenance theories helpful to others.)

George,

No sarcasm intended, but I'm struggling with your notion that somehow installing a generic, non tso'd battery box, modified by the installer (who may or may not be an A & P) in a certificated aircraft is somehow okay, but installing an airplane part that has been accepted by the FAA is not, even when blessed by an FAA inspector and a certified mechanic.

You insist in another thread on this list that you recommend installing an Aircraft Spruce generic battery box (which is not an airplane part) in the Cessna 170 rather than installing a Cessna 170 box or a replacement under the provisions of a field approval. Yet the original 170 battery box is still available new (according to at least one poster, anyway), and certainly is available in the salvage market.

I guess I'm just confused, but I've been there before, and it's not a big dissapointment to me.

Nonetheless, there seems to be some distinct inconsistency in your logic.

But, that's just my opinion.

Mike

Well, perhaps you didn't read far enough Mike.
The rule allows an owner to produce his own parts. It's a long rule with plenty of caveats, but basically it allows an owner to reproduce parts for his own aircraft as long as they essentially are the same as those being replaced. (You got a piece of the correct type of steel? You got a file and some crocus cloth? You got the specifications, the talent, and the time for the job? Make your own crankshaft if you want.) There is no requirement in the rule for the owner to be a certificated mechanic/repairman. (This is an example of a concept that will require more time than I'm willing to devote to what seems to be a point of contention with you....so I suggest you simply contact your FSDO and ask them to walk you through it.)
An excellent example of an owner-produced part is when you send your worn out, cracked muffler to the overhaul shop and they salvage a piece of it (or not), manufacture a completely new muffler and send it back to you. What they have done is use your work order (verbal or otherwise) to duplicate the original part and return it to you. You have participated, specified, controlled the production of that part. (To be completely legal however, you should do so in writing.)
The other msg thread you likely read involved taking a non-PMA'd battery box (intended probably for experimental aircraft) and modifying it (as the owner) to comply with the "owner produced parts" rule. In other words, using aircraft quality materials and making your own battery box. (The materials I thought might work in that thread happened to already be assembled into a generic box. As it turned out, the owner in that thread decided against that as it would require too much work for his expertise/effort/spare time. The owner produced parts rule does not require that the original, correct parts no longer be available, although that was likely a consideration when they wrote the rule.)
In any case, I did not "... insist..." on "... installing.." a "....generic battery box ... rather than installing a Cessna 170 box or a replacement under the provisions of a field approval." No insistance on my part occured whatsoever. The other party in the conversation was loathe to pay the price of the Cessna box and wanted an alternative. My suggestion to that person was to consider a generic box to modify under the owner produced parts rule,...that suggestion being made only to accomodate his desire to avoid the genuine Cessna part (which I most certainly did recommended to him first.)
It appears to me you might feel the need to "save face" in this thread and I'm sorry if I've come across so didactic or made you feel that way. My intent is to offer sound advice in a helpful, legal manner.
I'm really at a loss to understand why you still do not understand the difference between an aircraft part that was designed/certificated/PMA'd for a completely different aircraft than your own ...and the SPECIFIC aircraft parts PMA'd for your Cessna that may be installed on your aircraft without further basis of approval....and why the PMA'd Maule part cannot be used on your Cessna (without further basis of approval such as STC, field approval, etc.) It seems a pretty simple concept to me. You'll have to get someone better than me with more time than me to illustrate it to you I guess. But if your mechanic did it and took on the responsibility of signing it off....it shouldn't pose a big problem for you as long as nothing goes wrong with it.
(And just to avoid further conflict over this....NO you may not use compression springs in lieu of tension springs and call them "owner produced parts". Firstly, as owner one must control/specify/participate in the design, modification, or production of the part...simply paying for them doesn't qualify...and Owner produced parts must function the same as the original part. Fact is most people install them thinking and hoping that very functional difference of compression springs from tension springs is the cure-all to cover-up faulty tailwheel maintenance/operation problems.)

George,

Good luck trying your battery box trick in this FSDO district. But you certainly proved one thing to the assemblage.

Mike

It's not a "trick" and it's not mine. They're the ones who wrote the rule. You telling me your FSDO doesn't recognize their own rules? (Or you just still sniping?)

George,

Sorry, I have no intent to snipe here, and if I came across that way, I apologize. I've tried to offer information on this site which may be of use to someone, only to have you attack virtually everything I've said as being illegal, immoral, or somehow unworthy of consideration.

I don't preach gospel, and I'll be the first to tell anyone that not everything I say on one of these posts is thoroughly researched, upheld in an NTSB hearing, and therefore a fact. My offerings are simply opinions and things which have worked for me. This, by the way is also my assumption for everyone else's posts on these sites.

I have argueably one of the most technically legal airplanes in this state, with paper on virtually everything. It wasnt' always that way, but I've tried to educate myself, and improve my chances of avoiding problems down the road, legally. I also have a highly modified aircraft, with, as far as my maintenance folks can tell, all the mods perfectly legal. I don't make up the rules, AND I don't interpret them. I simply allow the professionals who are PAID to interpret the rules to do so, and report what happens. Nobody on this site is getting paid, near as I can tell, to offer professional opinions. That doesn't mean the information isn't correct, mind you, just that sometimes you get what you pay for. And, of course the converse is true as well--you pay for bad information. Been there, too.

I have emphasized repeatedly that most if not all the maintenance "policies" of the FAA are subject to interpretation, and the interpretations are routinely different in different districts, and between different inspectors.

Shouting someone down and accusing them of "sniping" simply because you don't agree with some maintenance procedure that their FSDO has adopted as legal is pointless and counterproductive.

As such, it is quite apparent that this is your policy, and since this is your forum to run, I wish you the best with it.

In parting, I'd simply suggest that folks not take everything on any internet forum (including the posts I make) as "gospel".

See ya,

Mike

Mike....your comment "only to have you attack virtually everything I've said as being illegal, immoral, or somehow unworthy of consideration. " is an incorrect, untrue, wild exaggeration and simply an attempt to defend misplaced pride. Point out where I said everything you've said is "immoral" or "unworthy of consideration" and I'll eat my words. (That accusation is unworthy of belief. I believe it's really your pride that's been hurt because you made cavalier comments that don't stand up to scrutiny. Please don't accuse me of what I've not said.)
First, I didn't say it was illegal...IF your mechanic assumed the responsibility. In fact I said the exact opposite....IF your mechanic signed it off.
The only concept that I've held that runs counter to yours in this thread has been regarding your stated position that if it's an airplane part for some other airplane....then it must be legal for any/your airplane. You should know better than to try to pass that view off as legitimate.
If you "tried to offer information on this site which may be of use to someone"...then for goodness sakes make certain the information is correct ...or be willing to accept when you've given incorrect info. Using parts on aircraft for which they are not PMA'd is not legal ....without additional basis of approval....and that fact shouldn't get you all wrapped around the axle.
"I have argueably one of the most technically legal airplanes in this state, with paper on virtually everything." Great. That's fine. But I feel compelled to say that the most fraudulent, fictitious logbooks I've ever seen belonged to a piece of junk formerly owned by an AP/IA who had generated more B.S. (beautiful as it read ... it was all fiction.) I'm sure others have seen this as well.
Paperwork in itself isn't necessarily good maintenance.

mvivion wrote: Nobody on this site is getting paid, near as I can tell, to offer professional opinions. That doesn't mean the information isn't correct, mind you, just that sometimes you get what you pay for. Mike

Quite right. You haven't paid for anything. This site is supported by TIC170A members. As a non-profit, it is produced by volunteers. No one is being paid. However, the volunteers and many contributors here are professionals and others with good years of experience. You don't have to use the free information you obtain here.
You haven't been "shouted down". You've been disagreed with...because the information you espoused is, quite frankly, incorrect, and the reasoning behind the disagreement has been carefully stated. There's no reason to get insulting because someone disagrees and explains their reasoning. That's just another form of sniping and this forum isn't fun for anyone when it degrades to that.