×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Using a PMA's replacement for to establish equivalence?

Using a PMA's replacement for to establish equivalence?

Using a PMA's replacement for to establish equivalence?

(OP)
Howdy all,

I was looking for a set of switches, 813387-3/-4/-5 and they each have a long list of PMA parts. Removing duplicates there are 23 separate PMA parts that are common to all three of these parts. These 23 PMA parts are approved as alternates for multiple OEM parts. In fact there are 25 different OEM parts that these PMA parts are allowed alternates for. 19 of the PMA parts have the same list of 23 OEM Parts they replace.

So I expect these switches are all identical, with perhaps the only difference being wire length, but they list a different P/N for each top level part number they go on. Could I use this to justify using an alternate OEM part number to use an equivalent, perhaps identical switch from a different part?

Thanks,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

RE: Using a PMA's replacement for to establish equivalence?

how do you spell "money making scheme" ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

RE: Using a PMA's replacement for to establish equivalence?

Maybe you could justify it if the replacement OEM part is from the same OEM as original.
But don’t you need to get FAA/TC approval anyway?

RE: Using a PMA's replacement for to establish equivalence?

KW... Hmmmm...

PN [switches] 813387-3/-4/-5 makes no sense: is this a vendor #? MIL-S-#? MS#? etc... digits seem to long for MIL/MS.

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

RE: Using a PMA's replacement for to establish equivalence?

(OP)
I think this has the economic benefit that rb1957 suggests, and a legal benefit that if there is a problem, something that could turn into an AD, it limits the scope of the AD. I also think the OEM may have different cable lengths and all the PMA options probably have enough extra to trim as needed. but that's all just spit-balling.

SWComposites It's the same OEM for all the "equivalent" non-PMA parts. But yeah, it feels wrong to just say use this part from a different valve, it'll be okay.

Thanks all,

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

RE: Using a PMA's replacement for to establish equivalence?

I must be way off base, but I use the FAA DRS web site a lot for FAA-PMA so I thought I would look up your question. Note that everything I list is public information from the drs.faa.gov website. I found only the following for each part number:

813387-3AEC
813387-4AEC
813387-5AEC

In each case the PMA is held by Aviation Engineering Consultants under FAA-PMA PQ1685CE, Supplement 38 Amendment 1 for most Boeing, McDonnel-Douglas and Airbus transport category aircraft.

In addition I found only the following:

813387-3AEC

Again Aviation Engineering Consultants holds the FAA-PMA but under PQ1685CE, Supplement 51 for most ERJ aircraft.

I am unable to understand what document you are seeing that lists any other FAA-PMA articles?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close