Updating Panel with New Switches and Annunciator Lights

[Me & 8883]

Hi Folks,

I own a 1977 M20J and I'm looking forward to completely revamping my panel.  I'm speaking with several shops about the work and one recurring issue is with regard to replacement switches (breaker switches) and annunciator light replacements.  One shop told me I HAD to keep the existing switches and lights or purchase the exact same equipment to replace -no substitutions.  Other shops say they are happy to replace the Mooney breaker switches with, say, MS breaker switches, but there has to be some sort of STC in order to make the change.  I wouldn't mind MS breaker switches and aircraft annunciator lighting (simple red or green circles) on the panel with the panel properly labeled.  I know many others have done this before... Any guidance?

[ArtVandelay]

Some shops are better than others, this is what you want:



Where are you located, get some recommendations.

[Utah20Gflyer]

Does the wire have to be STCd too? Just wondering. 

[wombat]

Oh jeez I hope this doesn't devolve into an argument too....   But here we go!

The FAA has a thing or two to say about Aeronautical Replacement Parts.    You can read more here: https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-62E_CHG_1_Editorial_Update.pdf

The FAA has defined several types of parts.   (In their doc these are lettered, but the BB here can only do numbers and I'm too lazy to make the list manually)

1. FAA Approved Parts
2. Acceptable Parts
3. Article
4. Commercial Part
5. Product
6. Standard Part
7. Interface Component
8. Surplus
9. Overhauled
10. Rebuilt
11. As Is
12. Owner/Operator Produced Part
13. Time-Limited Part

 

The things I think we'd be most interested in are Standard Part (Paragraph 6(f)) and Owner/Operator Produced Part (Paragraph 6(n)).

 

f. Standard Part. A part manufactured in complete compliance with an established U.S. Government or industry-accepted specification, which includes design, manufacturing, and uniform identification requirements. The specification must include all information necessary to produce and conform to the part. The specification must be published so that any party may manufacture the part. Examples include, but are not limited to, National Aerospace Standard (NAS), Air Force/Navy (AN) Aeronautical Standard, Society of Automotive Engineers (SAE), Aerospace Standard (AS), Military Standard (MIL-STD), etc

n. Owner/Operator Produced Part. Parts that were produced by an owner/operator for installation on their own aircraft (i.e., by a certificated air carrier). An owner/operator is considered a producer of a part, if the owner participated in controlling the design, manufacture, or quality of the part. Participating in the design of the part can include  supervising the manufacture of the part or providing the manufacturer with the following: the design data, the materials with which to make the part, the fabrication processes, assembly methods, or the quality control (QC) procedures.

The FAA is also quite specific about Electrical Parts and Instruments, they wrote section 13 just for that.

13(b) is even more specific, it reads:

b. Discrete Electrical and Electronic Component Parts. Electrical and electronic parts, such as resistors, capacitors, diodes, and transistors, if not specifically marked by the equipment manufacturer’s part number or marking scheme, may be substituted or used as replacement parts, provided that such parts are tested or it is determined that they meet their published performance specifications and do not adversely affect the performance of the equipment or article into or onto which they are installed. The performance of such equipment or article must be equal to its original or properly altered or repaired condition. Integrated circuits such as hybrids, large scale integrated circuits (LSIC), programmable logic devices, gate arrays, application specific integrated circuits (ASIC), memories, Central Processing Units (CPU), etc., are not included because their highly specialized functionality does not readily lend itself to substitution.

And in general what we are talking about is the Replacement of Parts and Materials, which is paragraph 8 (a)

a. Replacement of Parts and Materials. The performance rules for replacement of parts and materials used in the maintenance, preventive maintenance, and alteration of aircraft that have (or have had) a U.S. airworthiness certificate, and components thereof, are specified in § 43.13 and part 145, § 145.201. These rules require that the installer of a part use methods, techniques, and practices acceptable to the FAA. Additionally, the installer of a part must accomplish the work in such a manner and use materials of such quality that the product or appliance worked on will be at least equal to its original or properly altered condition with respect to the qualities affecting airworthiness.

We can find 43.13 here: https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/section-43.13

 

 

So to answer @Utah20Gflyer's direct question, which I'm actually assuming was more of a joke, but I'm taking it seriously as an example of how I would try to use the document to answer the question about other parts....  The wire does not need to be STC'd as long as it is a MIL-STD or SAE wire.

For @Me & 8883's question about MS switches, I'm assuming we're talking about something like this one: https://www.aircraftspruce.com/catalog/elpages/7270_5_5.php?clickkey=32749   It says it's "MIL-C-5809 qualified", so my guess it this would be considered a 'Standard Part', and may be substituted or used as replacement parts.

 

 

Side note: In their document they mix singular and plural. (Part Vs. Parts) and that bothers me.

Edited March 22, 2023 by wombat

[Ragsf15e]

I think this part of @wombat answer is really important:

Additionally, the installer of a part must accomplish the work in such a manner and use materials of such quality that the product or appliance worked on will be at least equal to its original or properly altered condition with respect to the qualities affecting airworthiness.
 

Find a shop willing to use this to install newer/better.

[Fly Boomer]

21 hours ago, Me & 8883 said:

Other shops say they are happy to replace the Mooney breaker switches with, say, MS breaker switches, but there has to be some sort of STC in order to make the change.

I couldn't figure out what your MS abbreviation meant (MooneySpace?) until I read @wombat's comment above.  Based on his comment, it seems like it might be milspec.  Is that what you meant?

[PT20J]

10 hours ago, Fly Boomer said:

I couldn't figure out what your MS abbreviation meant (MooneySpace?) until I read @wombat's comment above.  Based on his comment, it seems like it might be milspec.  Is that what you meant?

Aircraft hardware is confusing and all attempts to make it better have seemingly made it worse.

Maybe this will help (from https://www.flywithspa.com/docs/pbm/toc453317738.html):

AN- ARMY-NAVY specification series started in the early 1940s as a means to standardize military items for World War II.  Mostly canceled in the 1950s, a few have survived to only a few years ago, AN3-AN20 bolt is one of the longest lived specs.

NAS- National Aerospace Standards, started in 1941 is handled by the Aerospace Industries Association a group of aerospace companies

From their brochure: The NAS series is best known for its state-of-the-art, high strength, precision fasteners. In addition to all types of screws, nuts, and rivets, NAS standards define high pressure hose, electrical connectors, splices and terminations, rod end bearings, and many other types of hardware and components.

MS- Military standard started around the 1950s and for the most part replaced the AN hardware series.  However, a few of the AN standards have stayed around.  The MS series was canceled in 1994 by the Secretary of Defense, at the request of contractors in order to save money.  However, many of the commercial companies used MS standard hardware for all there products.  The cancellation caused the aerospace community many problems, and there was a rush to create new standards to replace the MS ones.  Some of the following specs were the result.

NASM- approximately 500 military standards were converted by the NAS group to commercial specifications, but retain the original MS part number.  The spec that defines the part is NASM and then the numerical portion of the MS number.  Example, MS20426 rivet spec went to NASM 20426, but part number stayed MS20426.

AS- Aerospace Standards created by SAE International (originally Society of Automotive Engineers) some MS specifications were replaced by AS standards.  Unfortunately, the part number changed to AS then the number of the MS part.  MS21919 cushioned clamps changed to AS21919.

 

NOTE: Certified General Aviation aircraft many times uses the old part number as that is what the aircraft was certified with, and experimental aircraft typically follows the old numbers because the certified ones do.  Various hardware supply companies will ship the hardware with different numbers from what you order on the website.  

Example: Aircraft Spruce will list AN365 in the catalog, but ship it in bags labeled MS21044.

In aviation, course threads are standard for #2 through #8 screws, fine thread is standard for #10 (3/16”) and larger bolts.

[Utah20Gflyer]

12 hours ago, wombat said:

Oh jeez I hope this doesn't devolve into an argument too....   But here we go!

The FAA has a thing or two to say about Aeronautical Replacement Parts.    You can read more here: https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_20-62E_CHG_1_Editorial_Update.pdf

The FAA has defined several types of parts.   (In their doc these are lettered, but the BB here can only do numbers and I'm too lazy to make the list manually)

1. FAA Approved Parts
2. Acceptable Parts
3. Article
4. Commercial Part
5. Product
6. Standard Part
7. Interface Component
8. Surplus
9. Overhauled
10. Rebuilt
11. As Is
12. Owner/Operator Produced Part
13. Time-Limited Part

 

The things I think we'd be most interested in are Standard Part (Paragraph 6(f)) and Owner/Operator Produced Part (Paragraph 6(n)).

 

f. Standard Part. A part manufactured in complete compliance with an established U.S. Government or industry-accepted specification, which includes design, manufacturing, and uniform identification requirements. The specification must include all information necessary to produce and conform to the part. The specification must be published so that any party may manufacture the part. Examples include, but are not limited to, National Aerospace Standard (NAS), Air Force/Navy (AN) Aeronautical Standard, Society of Automotive Engineers (SAE), Aerospace Standard (AS), Military Standard (MIL-STD), etc

n. Owner/Operator Produced Part. Parts that were produced by an owner/operator for installation on their own aircraft (i.e., by a certificated air carrier). An owner/operator is considered a producer of a part, if the owner participated in controlling the design, manufacture, or quality of the part. Participating in the design of the part can include  supervising the manufacture of the part or providing the manufacturer with the following: the design data, the materials with which to make the part, the fabrication processes, assembly methods, or the quality control (QC) procedures.

The FAA is also quite specific about Electrical Parts and Instruments, they wrote section 13 just for that.

13(b) is even more specific, it reads:

b. Discrete Electrical and Electronic Component Parts. Electrical and electronic parts, such as resistors, capacitors, diodes, and transistors, if not specifically marked by the equipment manufacturer’s part number or marking scheme, may be substituted or used as replacement parts, provided that such parts are tested or it is determined that they meet their published performance specifications and do not adversely affect the performance of the equipment or article into or onto which they are installed. The performance of such equipment or article must be equal to its original or properly altered or repaired condition. Integrated circuits such as hybrids, large scale integrated circuits (LSIC), programmable logic devices, gate arrays, application specific integrated circuits (ASIC), memories, Central Processing Units (CPU), etc., are not included because their highly specialized functionality does not readily lend itself to substitution.

And in general what we are talking about is the Replacement of Parts and Materials, which is paragraph 8 (a)

a. Replacement of Parts and Materials. The performance rules for replacement of parts and materials used in the maintenance, preventive maintenance, and alteration of aircraft that have (or have had) a U.S. airworthiness certificate, and components thereof, are specified in § 43.13 and part 145, § 145.201. These rules require that the installer of a part use methods, techniques, and practices acceptable to the FAA. Additionally, the installer of a part must accomplish the work in such a manner and use materials of such quality that the product or appliance worked on will be at least equal to its original or properly altered condition with respect to the qualities affecting airworthiness.

We can find 43.13 here: https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/section-43.13

 

 

So to answer @Utah20Gflyer's direct question, which I'm actually assuming was more of a joke, but I'm taking it seriously as an example of how I would try to use the document to answer the question about other parts....  The wire does not need to be STC'd as long as it is a MIL-STD or SAE wire.

For @Me & 8883's question about MS switches, I'm assuming we're talking about something like this one: https://www.aircraftspruce.com/catalog/elpages/7270_5_5.php?clickkey=32749   It says it's "MIL-C-5809 qualified", so my guess it this would be considered a 'Standard Part', and may be substituted or used as replacement parts.

 

 

Side note: In their document they mix singular and plural. (Part Vs. Parts) and that bothers me.

I was mostly joking, but also expressing some frustration with the aviation industry and the bureaucracy that’s developed. 

Thank you for your well documented post, it’s obviously much more valuable than my sarcasm.

I think we are overdue for a review of the current safety regime.  We really need to look at whether what we are doing is providing the result that was intended and whether there aren’t better ways to accomplish the goal we are striving for which is to protect human life.  I have noticed many times the correct answer to complex questions are counterintuitive.  
 

Without a precisely stated goal and a way to test the efficacy of a new rule we have no way of knowing whether it is creating a positive or negative result.   Just look at the 1500 hour rule for the airlines.   We know time in type is more important than total time when it comes to accident rates but we force pilots to waste time going around the pattern doing touch and goes.  A type of flying which has almost nothing to do with the skill set needed for operating a jet.  This will likely get people killed.
 

An STC for a common electrical switch seems like a good way to degrade safety in the name of being safe.  

 

[PT20J]

I think the FAA understands that the certification rules are an issue that increases cost and impedes safety enhancements. The FAA has made some notable strides such as the Part 23 rewrite that changed prescriptive design requirements to performance-based airworthiness standards, and the Non-required safety enhancing equipment (NORSEE) program. Also, many regions have been approving simple parts replacements without requiring STCs. And, the one that affected many of us was the FAA's willingness to work with Garmin to bring experimental avionics (most importantly the GFC 500) into the certified world which greatly decreased the cost of new autopilots.

EDIT: Two more: Approving ATDs for flight training and proficiency credit. Basic med.

Skip

[ttflyer]

On 3/21/2023 at 2:12 PM, ArtVandelay said:

Some shops are better than others, this is what you want:



Where are you located, get some recommendations.

So...  Out of curiosity:   Do you know which switches those are?  Brand / PN?  My perspective installer is giving me the "switches are a problem" answer right now...  We haven't signed anything yet.  But are getting close.   (For install October / November).

BTW, I did reach out to Treasure Coast Avionics.  Sent them a pic of our current panel and what we wanted to do.  She said, no problem!  Quote in a few days!  Six weeks and several emails later...  No quote.  These installers are so busy, I guess anything less then 100K isn't worth their time....

[ArtVandelay]

So...  Out of curiosity:   Do you know which switches those are?  Brand / PN?  My perspective installer is giving me the "switches are a problem" answer right now...  We haven't signed anything yet.  But are getting close.   (For install October / November).
BTW, I did reach out to Treasure Coast Avionics.  Sent them a pic of our current panel and what we wanted to do.  She said, no problem!  Quote in a few days!  Six weeks and several emails later...  No quote.  These installers are so busy, I guess anything less then 100K isn't worth their time....

I don’t know exact part number(s).

Every shop sucks at communicating with customers. TCA is booked solid. Pro tip, try calling and don’t bother leaving a message, probably best time of day is 3:30-4:30. I’ve been waiting for a check for several weeks, I feel your pain.

[gevertex]

On 3/24/2023 at 3:36 PM, ttflyer said:

So...  Out of curiosity:   Do you know which switches those are?  Brand / PN?  My perspective installer is giving me the "switches are a problem" answer right now...  We haven't signed anything yet.  But are getting close.   (For install October / November).

BTW, I did reach out to Treasure Coast Avionics.  Sent them a pic of our current panel and what we wanted to do.  She said, no problem!  Quote in a few days!  Six weeks and several emails later...  No quote.  These installers are so busy, I guess anything less then 100K isn't worth their time....

I can post my logbook entry once I get the mine back. It's supposed to wrap up this week. It was supposed to wrap up 3 weeks ago... but who's counting. They seem slammed so I give them a little slack.

[jlunseth]

I redid my panel probably twelve years ago. I am sure you know this, there are two types of lights on the panel, the lights interior to each gauge and little “down” lights exterior to the gauges that light up the panel generally.  There were circle lights that the installer used with the gauges, rather than trying to replace bulbs in the little “down” lights that were on the panel from the factory. They are nice, never had a problem with them. Don’t know brand or anything. I think they are LEDs, last forever.