FAA regulation

[Ulysse]

Hello,

 

I am looking for the FAA regulation which clearly states that if an aircraft is equiped with a non STCd component (e.g avionics, engine, propeller etc) then that aircraft is un-airworthy and therefore cannot be granted a CofA

Thanks in advance for the help

[takair]

I don’t think there is such a regulation. There are many other ways of have approved parts on an airplane.  There are some components where an STC is the preferred, but not only way.  Engines and autopilots are examples, but even those have been approved via field approval, in the past. Do you have a specific example?

[EricJ]

7 hours ago, Ulysse said:

Hello,

 

I am looking for the FAA regulation which clearly states that if an aircraft is equiped with a non STCd component (e.g avionics, engine, propeller etc) then that aircraft is un-airworthy and therefore cannot be granted a CofA

Thanks in advance for the help

Is there a question?    If there's a question it'll likely help to know which reg you're looking at in order to determine applicability, etc.

[Vance Harral]

4 hours ago, takair said:

There are many other ways of have approved parts on an airplane.

This is, IMO, the most difficult thing to understand about parts on certified airplanes.  Everything installed on a certified airplane must have a "basis for approval".  But there are many, many such approval mechanisms, including at least:

• part listed on original type certificate
• replacement part provided by a manufacturer with PMA
• aftermarket modification with STC
• aftermarket component which meets a TSO
• aftermarket component meets NORSEE standards
• replacement or add-on is an "industry standard part", see https://www.faa.gov/sites/faa.gov/files/aircraft/safety/programs/sups/standard_parts.pdf
• replacement or add-on is judged in the opinion of an appropriately certified mechanic to be a "minor modification"
• aircraft is a "vintage" aircraft and part falls under new VARMA regulations

Anyone who tells you that you can't install a non-original part on a certified aircraft without an STC is ill-informed.  But that doesn't mean you can install anything you want regardless of STC.  If there is no STC which permits installation of the component on your certified aircraft, then there must be some other basis for approval: TSO, NORSEE, signoff as "minor modification", etc.

The "minor modification" sign-off is the one that generates the most argument.  Appendix A of 43.13 explicitly lists items that count as major repairs/alterations, such that a mechanic cannot really claim those specific items are "minor modifications".  Beyond that, though, the definition of what constitutes a minor modification is - best as I can tell - just up to the judgement of the individual mechanic.  Some mechanics are a lot more liberal than others with this interpretation.

[EricJ]

37 minutes ago, Vance Harral said:

This is, IMO, the most difficult thing to understand about parts on certified airplanes.  Everything installed on a certified airplane must have a "basis for approval".  But there are many, many such approval mechanisms, including at least:

• part listed on original type certificate
• replacement part provided by a manufacturer with PMA
• aftermarket modification with STC
• aftermarket component which meets a TSO
• aftermarket component meets NORSEE standards
• replacement or add-on is an "industry standard part", see https://www.faa.gov/sites/faa.gov/files/aircraft/safety/programs/sups/standard_parts.pdf
• replacement or add-on is judged in the opinion of an appropriately certified mechanic to be a "minor modification"
• aircraft is a "vintage" aircraft and part falls under new VARMA regulations

Anyone who tells you that you can't install a non-original part on a certified aircraft without an STC is ill-informed.  But that doesn't mean you can install anything you want regardless of STC.  If there is no STC which permits installation of the component on your certified aircraft, then there must be some other basis for approval: TSO, NORSEE, signoff as "minor modification", etc.

The "minor modification" sign-off is the one that generates the most argument.  Appendix A of 43.13 explicitly lists items that count as major repairs/alterations, such that a mechanic cannot really claim those specific items are "minor modifications".  Beyond that, though, the definition of what constitutes a minor modification is - best as I can tell - just up to the judgement of the individual mechanic.  Some mechanics are a lot more liberal than others with this interpretation.

It's way muddier than all that.   And there are additional "approvals", like appearing in the IPC, etc.

I've yet to see what "new VARMA regulations" are or what they really say or how they're codified.   I've seen a document that references some old ACs, but not much past that.   That said, those old ACs are useful.

In the end, it is up to the judgement of the installer, and subject to inspection at the next annual.   

[Hank]

No one has mentioned Owner Produced Parts, either . . . . . .

[Vance Harral]

3 hours ago, EricJ said:

there are additional "approvals", like appearing in the IPC, etc.

Yep, I missed that one.

2 hours ago, Hank said:

No one has mentioned Owner Produced Parts, either . . . . . .

... and that one too.

3 hours ago, EricJ said:

I've yet to see what "new VARMA regulations" are or what they really say or how they're codified

I don't know much about it either, but as with "minor modifications" and "standard parts", I expect it will boil down to the interpretation of individual mechanics.

I deliberately prefixed my list of methods for approval with "at least" because I was sure I'd miss some.  The point is simply that there are many different avenues of approval, so the question asked in the OP isn't really meaningful.  It's like asking what regulation prohibits a person from getting a pilot certificate in a certain scenario.  There aren't any such regulations.  There only regulations that define a variety of methods for various people to obtain various pilot certificates, and you can get one via any of them: traditional experience/check ride, military equivalency, foreign certificate equivalent, etc.

[Ulysse]

8 hours ago, EricJ said:

Is there a question?

I'll be more specific:

I am looking at an airplane which mounts an aftermarket propeller which does not have an STC for this specific model/engine. The aircraft is currently on a foreign registry with a local approval.

I would like to know if this plane can be considered as airworthy by the FAA and if it can be registered on the N registry and receive a certificate of airworthiness or if I should consider replacing the propeller before presenting the plane to a DAR.

[Fly Boomer]

12 minutes ago, Ulysse said:

I'll be more specific:

I am looking at an airplane which mounts an aftermarket propeller which does not have an STC for this specific model/engine. The aircraft is currently on a foreign registry with a local approval.

I would like to know if this plane can be considered as airworthy by the FAA and if it can be registered on the N registry and receive a certificate of airworthiness or if I should consider replacing the propeller before presenting the plane to a DAR.

That is not a battle you will want to have every year during annual.  You need some kind of permanent approval or a new prop.

[EricJ]

39 minutes ago, Ulysse said:

I'll be more specific:

I am looking at an airplane which mounts an aftermarket propeller which does not have an STC for this specific model/engine. The aircraft is currently on a foreign registry with a local approval.

I would like to know if this plane can be considered as airworthy by the FAA and if it can be registered on the N registry and receive a certificate of airworthiness or if I should consider replacing the propeller before presenting the plane to a DAR.

The short answer is no, as a non-approved propeller is a pretty significant thing, not like a smaller part or modification.    Propellers are listed specifically in the TCDS, so one needs a STC or some sort of other formal approval like a field approval, which is not trivial to do.   I'd suggest just getting an approved propeller fitted.

Since you need to engage a DAR anyway, I'd ask this question to the specific DAR that you use ahead of time, since their opinion will be the most important one. 

[OR75]

1 hour ago, Ulysse said:

I'll be more specific:

I am looking at an airplane which mounts an aftermarket propeller which does not have an STC for this specific model/engine. The aircraft is currently on a foreign registry with a local approval.

I would like to know if this plane can be considered as airworthy by the FAA and if it can be registered on the N registry and receive a certificate of airworthiness or if I should consider replacing the propeller before presenting the plane to a DAR.

every year, you will need an IA to sign that the aircraft is approved for return to service

At some point, an IA (in theory at your first annual) will check that all components had a basis to be installed (STC, field approval , ....). A prop is major component so it is unlikely to go unnoticed.

the local approval may be a basis for the approval (for example, the FAA,  CAA ,  EASA have agreements to validate modification / approvals).

if the local approval is from a local mechanic in a remote country with not many standards ... it may be difficult to use that as a basis for approval

[takair]

1 hour ago, Ulysse said:

I'll be more specific:

I am looking at an airplane which mounts an aftermarket propeller which does not have an STC for this specific model/engine. The aircraft is currently on a foreign registry with a local approval.

I would like to know if this plane can be considered as airworthy by the FAA and if it can be registered on the N registry and receive a certificate of airworthiness or if I should consider replacing the propeller before presenting the plane to a DAR.

As Eric mentioned, prop combinations are at the more difficult end of the certification spectrum.  Was there any engineering that backed up the install in the other jurisdiction?  If the harmonics were not analyzed, tested, it could theoretically be doing fatigue damage to the crank/internals.  This may be a bigger consideration than the legality.  

[Ulysse]

is there an FAA office I could contact in order to get an official answer?

[midlifeflyer]

4 hours ago, Ulysse said:

is there an FAA office I could contact in order to get an official answer?

Any FAA office would be happy to ground an airplane with no official paperwork approval for a non-compliant prop. 

I'd  be working with a very knowledgeable mechanic or DAR who could look at whatever local paperwork you do have and understands the rules and the bases for approval @Vance Harraltalked about earlier.
 

[N201MKTurbo]

There are official FAA documents about reciprocal agreements with foreign agencies. If you have approval from a foreign agency, the FAA may be obligated to accept it. I would check the documents.

[N201MKTurbo]

6 hours ago, Ulysse said:

is there an FAA office I could contact in order to get an official answer?

You would want to talk to a principal inspector at the FSDO. They would rather talk to your IA, but it doesn’t hurt to call and ask. Some of them prefer e-mail. If you go to the FSDO website, use the contact email and the admin will route it to the right person.

[Fly Boomer]

On 6/10/2023 at 1:50 AM, Ulysse said:

is there an FAA office I could contact in order to get an official answer?

As @N201MKTurbo pointed out, a FSDO is a likely contact point, but since the pandemic. it is nearly impossible to get a face-to-face meeting -- they seem to only want email contact.