Sourcing Replacement Parts for an Old(ish) Airplane

kontiki

kontiki

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Kontiki
As a new owner, I'm finding all sorts of little things I want to address.
It's clear where the big parts have to come from, and I bought the IPC, but what about adelle clamps, standoffs, wire conduit, tie wraps, bulbs, grommet edging etc, is there any guidance on where they have to come from?

I called the TC holder and asked them to look at their installation DWG for a P/N or spec number on the clear plastic tubing used in the pitot system. They called back and told me all it says is 1/4 " ID PVC tubing with .063" wall.

Are there no restrictions on where really undefined materials have to come from?
 
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Chief, Univar, Wenthworth, Dotson, Discount aircraft.

lots of them.
 
The answer is "it depends." Most generic airplane parts I need come from Spruce. A few come from specialty shops. I have sourced parts from Mouser.

What do you fly? Have you had the discussion with your mechanic about owner-assisted maintenance?
 
Ted DuPuis said:
The answer is "it depends." Most generic airplane parts I need come from Spruce. A few come from specialty shops. I have sourced parts from Mouser.

What do you fly? Have you had the discussion with your mechanic about owner-assisted maintenance?
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I picked up a Grumman Tiger about a month ago. I'm an A&P that really hasn't done much GA work, but have been active in the airline world as a mechanic and engineer since I got my ticket in 79.

I didn't ask the mechanic that did the pre-buy about parts. I did ask about some of the work that needed to be done and he said he thought I should just go for it. I do know other owner, pilot, A&Ps, tons of engineers, etc and will probably have these same discussions with them as I go.

During the pre-buy there was an AD that came up and special bolts needed, that they couldn't find and were going to reuse after re-interpretation of the requirements. I used Google to eventually find out Fletch Air had a PMA to make them and had them here in 24 hrs. There probably wasn't anything wrong with them, but I couldn't see messing around on a wing spar AD. Whats $250.00, an hour in a complex rental with a CFI?

I suspect I may know more about some of these topics a result of work I've done professionally. I really don't have a sense how things are usually handled in GA. I may also look for a good mechanics message board.

Understand, tonite when I'm at work I could get a request for alternate wire to use in a a 757 engine pylon repair. Typically, I'd assist maint with finding all the pre approved alternates and give them a list of wire types and p/ns that I'm willing to write a company Engineering Authorization to approve. At an airline, the materials department and QA actually qualify the vendors approved to sell us the wire.

I don't believe you get an 8130 for parts that don't have at least a serial number, although I don't know exactly how part 121 specifies the audit trail for parts. None of that is really relevant to what I'm doing anyway, Its one thing to know what the spec for a good part is, its another to satisfy a parts traceability under Part 91.

The last time I read up on PMA and parts approval, I recall seeing a category of parts (maybe a list) recognized as PMA because they are defined by common specifications.

I have a hardcopy of the 43.13 coming, just to make review and scan that much easier. I really need to review Part 43 too and maybe the FARs on parts too?

If I plan to do anything significant (high risk or expensive) on my airplane, I will certainly get the assistance of a more active A&P, current with knowledge of type.

For right now, when I see wire (early factory mod?) chafing against the edge of a lightning hole where an old slab of rubber is peeling away, I'll re-cement it and tie wrap it for now, and will have a supply of caterpillar gromet, stand offs and wire clamps for the next time.
 
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kontiki said:
Are there no restrictions on where really undefined materials have to come from?
Click to expand...

It all depends on you. Talk to one of the new kids in the FSDO who have never swung a wrench in anger in their lives you will get that they want the paper you copy down clearances on from a TSO source. Talk to one of the older folks whose blood is 5606 and you will get pointed to the nearest aviation department at Home Depot.

It is YOUR comfort level. Nobody will ever know that the tubing you use for the vacuum instruments comes with a yellow tag or from the roll down at True Value.

Oldish airplanes have a saviour. It has been well documented in this group. Read 21.303(b)(2). Read it again. Then go HERE:

http://www.google.com/url?sa=t&rct=...=FHfwRKVMU1sFnq8beSLAeQ&bvm=bv.52434380,d.b2I

to see what the FAA Chief Counsel had to say about owner produced parts in August 1993. (If anybody has a direct URL to the original of this document I'd appreciate the link.)

Thanks,

Jim
 
Parts substitution can be quite an ordeal to overcome with your mechanic as opinions vary greatly.

For instance;

A carb heat cable is unavailable for Grumman AA-1C, what do you do?

The Grumman guy who sells the approved cable says "buy one from Joe Blows aircraft parts for a Cessna 150 and trim to length" legal or not?

The cable is PMA'ed for the Cessna 150.
 
kontiki said:
During the pre-buy there was an AD that came up and special bolts needed, that they couldn't find and were going to reuse after re-interpretation of the requirements.
Click to expand...
Ah, yes -- the wing shoulder bolt inspection AD.

I used Google to eventually find out Fletch Air had a PMA to make them and had them here in 24 hrs. There probably wasn't anything wrong with them, but I couldn't see messing around on a wing spar AD.
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Not the spar, actually, just the shoulder bolts that hold the wing from sliding off the center spar. In any event, you've found one of the two main parts providers for Grumman-specific parts, the other being Air Mods NW (http://airmodsnw.com/).

In any event, for the non-specific parts like Adel clamps, nuts and bolts, and the like, Aircraft Spruce is my go-to source since they always seem to have whatever I need at a good price with fast service. Yes, you may save a few cents shopping around, but I stick with the store that always has what I need, when I need it, at a reasonable price.

BTW, the problem with re-using the shoulder bolts once you've pulled them to inspect them is that if you scratch the cadmium plating in the process, they're scrap metal, and it's hard to pull them without scratching them. Fortunately, the AD mandates only a one-time inspection, even if the SB it quotes recommends doing the inspection every 500 hours, and I've yet to see any issues developing beyond 500 hours after the one-time inspection was completed, it's a long way to the 7250-hour limited life of the bolts themselves. Only planes which have had problems were the ones which weren't properly shimmed at the factory, and those were caught by the AD which came out 15 years ago.
 
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Ron Levy said:
Ah, yes -- the wing shoulder bolt inspection AD.

Not the spar, actually, just the shoulder bolts that hold the wing from sliding off the center spar. In any event, you've found one of the two main parts providers for Grumman-specific parts, the other being Air Mods NW (http://airmodsnw.com/).

In any event, for the non-specific parts like Adel clamps, nuts and bolts, and the like, Aircraft Spruce is my go-to source since they always seem to have whatever I need at a good price with fast service. Yes, you may save a few cents shopping around, but I stick with the store that always has what I need, when I need it, at a reasonable price.

BTW, the problem with re-using the shoulder bolts once you've pulled them to inspect them is that if you scratch the cadmium plating in the process, they're scrap metal, and it's hard to pull them without scratching them. Fortunately, the AD mandates only a one-time inspection, even if the SB it quotes recommends doing the inspection every 500 hours, and I've yet to see any issues developing beyond 500 hours after the one-time inspection was completed, it's a long way to the 7250-hour limited life of the bolts themselves. Only planes which have had problems were the ones which weren't properly shimmed at the factory, and those were caught by the AD which came out 15 years ago.
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Ron,

Thanks for the background on this. The AD came up in an awkward way on the prebuy. It caught both me and the seller buy surprise. In as much as the SB was repetitive my initial approach was to get past it by re-accomplishing it. Removal did scrape the plating off the bolts, so it goes. I didn't want it to be a deal breaker. Honestly, when debating the merits of looking at what may be problem areas or not (with incomplete knowledge), I'm always going to look.

I did also join the AYA and Grumman Gang. There is a wealth of info and 30 years of history to absorb. Plenty to do and look at, but it will all be fine I'm sure. I really like flying that little thing.
 
weirdjim said:
It all depends on you. Talk to one of the new kids in the FSDO who have never swung a wrench in anger in their lives you will get that they want the paper you copy down clearances on from a TSO source. Talk to one of the older folks whose blood is 5606 and you will get pointed to the nearest aviation department at Home Depot.

It is YOUR comfort level. Nobody will ever know that the tubing you use for the vacuum instruments comes with a yellow tag or from the roll down at True Value.

Oldish airplanes have a saviour. It has been well documented in this group. Read 21.303(b)(2). Read it again. Then go HERE:

http://www.google.com/url?sa=t&rct=...=FHfwRKVMU1sFnq8beSLAeQ&bvm=bv.52434380,d.b2I

to see what the FAA Chief Counsel had to say about owner produced parts in August 1993. (If anybody has a direct URL to the original of this document I'd appreciate the link.)

Thanks,

Jim
Click to expand...

Thanks Jim,

Where the first page is skewed and truncated, I went here to look for a better copy. No joy though. I don't understand that. See ->

http://www.faa.gov/about/office_org.../agc/pol_adjudication/agc200/interpretations/
 
Ron Levy said:
BTW, the problem with re-using the shoulder bolts once you've pulled them to inspect them is that if you scratch the cadmium plating in the process, they're scrap metal, and it's hard to pull them without scratching them.
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Why can't they be re-plated?
 
Tom-D said:
Why can't they be re-plated?
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Because cadmium has been put in the column of methyl-ethyl-death and is a hazardous material. Cad plating is VERY expensive for the same reason that ni-cad batteries are treated as a haz-mat at the battery disposal site.

THere are DOZENS of platings/passivatings better than cad these days, but my suspect is that the FAA, in its infinite wisdom, refuses to consider them.

Jim
 
weirdjim said:
Because cadmium has been put in the column of methyl-ethyl-death and is a hazardous material. Cad plating is VERY expensive for the same reason that ni-cad batteries are treated as a haz-mat at the battery disposal site.
Jim
Click to expand...

Not true Jim, I have hardware re-plated for every engine I do, ASKO processes in Seattle does a fine job of type II cad with an aviation bake.

180 pieces for 200 bucks.

http://www.askogroup.com
 
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I do a lot of business with Spruce, not because they're always the cheapest, but because they've always shipped quickly and have been extremely consistent.
 
Tom-D said:
Not true Jim, I have hardware re-plated for every engine I do, ASKO processes in Seattle does a fine job of type II cad with an aviation bake.

180 pieces for 200 bucks.

http://www.askogroup.com
Click to expand...
I'll bet it would be the same $200 for four pieces as it would for 180 (batch price, I'm guessing, unless you want to ground the plane and wait for them to have a full batch) and you might as well buy four new ones for the same price. In any event, it's not an authorized method of compliance in this case. If you want to go to the FAA and get an AMOC approved, be my guest.
 
Ron Levy said:
I'll bet it would be the same $200 for four pieces as it would for 180 (batch price, I'm guessing,

You are guessing correctly.

unless you want to ground the plane and wait for them to have a full batch) and you might as well buy four new ones for the same price. In any event, it's not an authorized method of compliance in this case.

why not ?

If you want to go to the FAA and get an AMOC approved, be my guest.
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Is there any documentation in the AD that requires the bolts be thrown away?

Why does it require a alternate method of compliance to comply with the AD, to use a re-plated bolt?

I ask in earnest ? because we use re=plated parts

the Grumman gang should collect as many of the bolts as possible and get them re-plated and keep them on hand for members on a exchange bases.
 
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Tom-D said:
Is there any documentation in the AD that requires the bolts be thrown away?

Why does it require a alternate method of compliance to re-use a re-plated bolt?

I ask in earnest ? because we use re=plated parts

the Grumman gang should collect as many of the bolts as possible and get them re-plated and keep them on hand for members on a exchange bases.
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You read the AD and see if you find anything in there authorizing re-plated bolts. What it says is "replace" -- nothing else.
http://www.gpo.gov/fdsys/pkg/FR-2005-08-22/html/05-16260.htm
 
Ron Levy said:
You read the AD and see if you find anything in there authorizing re-plated bolts. What it says is "replace" -- nothing else.
http://www.gpo.gov/fdsys/pkg/FR-2005-08-22/html/05-16260.htm
Click to expand...

The AD says to comply with the SB, the SB says.

quote
a. Inspect for fretting or scoring to the shoulder of the bolt. If there is any wear resulting in removal of the cad plating from the shoulder of the bolt (other than normal minor marks caused by installation and removal), the bolt must be removed from service and a new bolt installed.

that pretty much says it all.

add this to the number of ADs that are written to sell parts.
 
> bulbs, tie wraps ...

I consider them to be "standard" parts ... and shop in the Aviation aisle of my favorite NAPA.

If your airframe is mfg'd before 1980; become familiar with this vintage aircraft maint Advisory Circular:

http://rgl.faa.gov/REGULATORY_AND_GUIDANCE_LIBRARY/RGADVISORYCIRCULAR.NSF/0/ccf7daac581048cd862575e6006ca078/$FILE/AC%2023-27.pdf

Mike Busch publishes a lot of good info & seminars on-line:

https://www.savvymx.com/index.php/webinar
 
Tom-D said:
Why can't they be re-plated?
Click to expand...

To be honest, I didn't look into it. I had the shop accomplish an annual immediately following the prebuy. The AD bolt thing came up in prebuy. At that point, I just didn't want the plane to sit in the hangar too long while we messed with bolts.

Also, Fletch Air holds the PMA for manufacturing the bolts. I suspect it would have to be one of their approved sub vendors that did the plating for it to to be approved. If the paperwork processes aren't already in place to the point it's routine, it could turn into another lengthy goat rope.

All in all, I was already overloaded with details from purchase of my first plane, I have limited free time and a lot to come up to speed on with the new airplane.

I expect that my maintenance costs will be higher than absolutely necessary first year on first airplane. As with all things I have done, I will learn and get the extra costs under control as I gain experience and knowledge. I do appreciate all the suggestions though.
 
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rainsux said:
> bulbs, tie wraps ...

I consider them to be "standard" parts ... and shop in the Aviation aisle of my favorite NAPA.

If your airframe is mfg'd before 1980; become familiar with this vintage aircraft maint Advisory Circular:
Mike Busch publishes a lot of good info & seminars on-line:

https://www.savvymx.com/index.php/webinar
Click to expand...

That concept is all well and good until part 39 kicks In and requires you comply with an AD which requires you replace the part with a new one.

I'll wager that in this case good bolts are being thrown away because most don't know what the CAD looks like after the yellow color is gone.
 
kontiki said:
To be honest, I didn't look into it. I had the shop accomplish an annual immediately following the prebuy. The AD bolt thing came up in prebuy. At that point, I just didn't want the plane to sit in the hangar too long while we messed with bolts.
Click to expand...
As Tom has since discovered by reading the AD involved, replating and replacing is not an authorized method of compliance. If the plating is damaged, the AD requires replacement with a new part, so you and your mechanic did exactly the right thing.
 
kontiki said:
To be honest, I didn't look into it. I had the shop accomplish an annual immediately following the prebuy. The AD bolt thing came up in prebuy. At that point, I just didn't want the plane to sit in the hangar too long while we messed with bolts.

Also, Fletch Air holds the PMA for manufacturing the bolts. I suspect it would have to be one of their approved sub vendors that did the plating for it to to be approved. If the paperwork processes aren't already in place to the point it's routine, it could turn into another lengthy goat rope.

All in all, I was already overloaded with details from purchase of my first plane, I have limited free time and a lot to come up to speed on with the new airplane.

I expect that my maintenance costs will be higher than absolutely necessary first year on first airplane. As with all things I have done, I will learn and get the extra costs under control as I gain experience and knowledge. I do appreciate all the suggestions though.
Click to expand...

In many cases like this, is difficult to prove the AD is complied with without complying with it again, and in so doing ruin good parts.
 
Ron Levy said:
As Tom has since discovered by reading the AD involved, replating and replacing is not an authorized method of compliance. If the plating is damaged, the AD requires replacement with a new part, so you and your mechanic did exactly the right thing.
Click to expand...

Show me any A&P-IA that knows every thing there is about all ADs on ALL aircraft, I'll show you a danger to us all.

It would have been way too easy for you to simply tell me the SB requires new parts, rather that try to BS about AMOC
 
I take it these Grumman bolts don't fall out like beech wings?


If the hole tollerance was near press fit, you couldn't install the bolt without damaging the cad plating... :mad2:
 
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If I read the the AD correctly, unless the bolt shows fretting or damage beyond the typical scratches of assembly and disassembly, it can be reused.
 
The AD says to comply with the SB, the SB says.

quote
a. Inspect for fretting or scoring to the shoulder of the bolt. If there is any wear resulting in removal of the cad plating from the shoulder of the bolt (other than normal minor marks caused by installation and removal), the bolt must be removed from service and a new bolt installed.
 
Tom-D said:
In many cases like this, is difficult to prove the AD is complied with without complying with it again, and in so doing ruin good parts.
Click to expand...
Not if it's properly documented in the aircraft maintenance records.

Unless, of course, you think the entry was falsified, in which case you're saying you don't believe what's in the maintenance records, and in that case, you have throw them away and start from scratch on everything ever done to the airplane -- essentially, disassemble it and put it back together again. I suppose that in some extreme cases where a lot of work was done by a mechanic who has since been shown to have falsified a lot of records you might need to do that, but I don't see that as a major concern normally.
 
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