What is PMAed, STDed, etc.?

wrote in message ...

An STC introduces an alteration that was not covered by the airplane's
original type certificate. Installation of an STCed part or system must be
accomplished in accordance with the STC. This may be a major or minor
alteration, but as I understand it, it would in any case need to be signed
off by an A&P, and possibly an AI. In many cases a new weight and balance
would need to be calculated and recorded.

An IA must sign off the 337, which is required of any major alteration. An STC
provides authority to make the major alteration. A minor alteration requires
neither a 337 nor an STC.

Ron Natalie wrote:

An IA must sign off the 337, which is required of any major alteration.
An STC
provides authority to make the major alteration. A minor alteration
requires neither a 337 nor an STC.

It sounds from the above like an STC is required before any major alteration
because it "provides authority to make the major alteration". Is that
right?

A lot seems to hinge on the distinction between "major" and "minor"
alterations. What is the difference? Given a particular change (ie.
replacing a panel overlay, or adding instrument lights), how does one know
into which category the change falls?

- Andrew

"Andrew Gideon" wrote in message online.com...

It sounds from the above like an STC is required before any major alteration
because it "provides authority to make the major alteration". Is that
right?

An STC is one way of getting approval for the alteration. Other "data
acceptable to the administrator" is allowed as well. This is called a
field approval (or sometimes incorrectly, a one time STC).

A lot seems to hinge on the distinction between "major" and "minor"
alterations. What is the difference? Given a particular change (ie.
replacing a panel overlay, or adding instrument lights), how does one know
into which category the change falls?

The definitions are here (I'm not going to post them inline as they are a bit long):
http://www.access.gpo.gov/nara/cfr/c...4cfr43_00.html

Some of it is a gray area. Somethings people read more into it than others.
For example, just because something changes the w&b, it is not a major
alteration. It is only a major alteration if it changes the permissable envelope.

Ron Natalie wrote:

The definitions are here (I'm not going to post them inline as they are a
bit long):
http://www.access.gpo.gov/nara/cfr/c...4cfr43_00.html

Appendix A(a) defines "major alteration". Anything else is "minor"?

Some of it is a gray area. Somethings people read more into it than
others. For example, just because something changes the w&b, it is not a
major
alteration. It is only a major alteration if it changes the permissable
envelope.

Where do you see that? I only see a list of items in A(a); nothing that
refers to the W&B.

- Andrew

"Andrew Gideon" wrote in message online.com...
Ron Natalie wrote:

The definitions are here (I'm not going to post them inline as they are a
bit long):
http://www.access.gpo.gov/nara/cfr/c...4cfr43_00.html

Appendix A(a) defines "major alteration". Anything else is "minor"?

Some of it is a gray area. Somethings people read more into it than
others. For example, just because something changes the w&b, it is not a
major
alteration. It is only a major alteration if it changes the permissable
envelope.

Where do you see that? I only see a list of items in A(a); nothing that
refers to the W&B.

43xA.a (1)(xi).
Changes to the empty weight or empty balance which result in an increase ...

Ron Natalie wrote:

43xA.a (1)(xi).
Changes to the empty weight or empty balance which result in an increase
...

Ah. Hidden in plain site.

Thanks...

- Andrew

On Wed, 19 Nov 2003 14:00:26 -0500, Andrew Gideon
wrote:

Ron Natalie wrote:

An IA must sign off the 337, which is required of any major alteration.
An STC
provides authority to make the major alteration. A minor alteration
requires neither a 337 nor an STC.

It sounds from the above like an STC is required before any major alteration
because it "provides authority to make the major alteration". Is that
right?

A lot seems to hinge on the distinction between "major" and "minor"
alterations. What is the difference? Given a particular change (ie.
replacing a panel overlay, or adding instrument lights), how does one know
into which category the change falls?

- Andrew

What is *required* before a major alteration is approved data. How
you obtain that can vary, STC, Field Approval, etc....

Well, technically, you don't really need it until the work is
inspected.......BUT..... Trust me, though, you want the approved data
*before* beginning *any* work.