Diagramming Wiring in Older GA Airplanes

[kontiki]

Owing to wiring repairs and maybe 15 or so STC mods incorporated over the years, as I've gone through the wiring on my airplane on my Grumman Tiger, I've diagrammed what I've found.

Much of the aircraft wiring really does not look like what's shown in the various wiring figures for the 2005 release of the Aircraft Maintenance Manual any more.

What are GA folks doing to identify wiring diagrams specific to an old airplane in GA?

 

[Bell206]

What are GA folks doing to identify wiring diagrams specific to an old airplane in GA?

Don't quite follow your question on "identifying" wiring diagrams. But as there is no requirement to provide an altered electrical schematic for every electrical alteration it usually is a crap shoot when figuring out the current config of an aircraft. Having rewired a number of aircraft I usually routed/marked replacement wires per the OEM schematics, then followed any 3rd party schematics if available, and then marked any remaining wirings as needed.

Only had one owner request a complete updated schematic of his entire aircraft which I provided via an enlarged OEM schematic and electronically drew in all the addtions. Then had it reduced and printed.

 

[kontiki]

Don't quite follow your question on "identifying" wiring diagrams.

Where it's my airplane, and I don't like repeating the pain of tracing wiring every time I need to check something. I captured everything I've gone over, everything I repaired, modifications I've made, modification others have made, in detailed cad wiring diagrams. I basically organized them by standard ICAO chapter numbering system. Chapter 34 = Navigation, Chapter 24 = Power etc. I stuck the registration number and aircraft serial number in the title box. I'm OK putting my name and A&P on anything I do, so I was thinking about adding that with a date. Didn't know if I should refer to them in logbook signoffs. Didn't know what other folks do to point to drawings and sketches they create. I'm probably a little OCD, but I replaced and repaired a lot of wire. No point for anyone to have to repeat the work I've done already. I'm frustrated that people installed equipment and didn't bother to add diagrams showing what they did. After going over their work, I can see why though.

 

[Bell206]

Didn't know what other folks do to point to drawings and sketches they create. I'm probably a little OCD,

Probably OCD due to your sparkie background. Since there is zero FAR requirement to provide any new schematic with an alteration nobody does it. And would the average owner pay extra for someone to do it? Doubtful. To be truthful, any lack of said schematic didn't really hinder any troubleshooting I've done over the years especially on small airplanes/helicopters. However, you are taking the extra mile and if I ran across one of your aircraft in my mx adventures I would definitely raise a glass to your endeavors.

 

[weirdjim]

OK, I've got one for the books. When I bought the blue-on-blue-182 back in 1989, it had the most horrific wiring loom I'd ever seen. I cut every wire out of that tin w#0re and started from scratch (a 6 month project). One switch on the panel was unmarked. I took the wire off of one terminal, followed it under the instrument panel, up the sidepost, across the headliner, across the spar carry-through, down the other headliner, down the other sidepost, under the instrument panel, to the other pole of the switch.

WTF????

Jim

 

[asicer]

OK, I've got one for the books. When I bought the blue-on-blue-182 back in 1989, it had the most horrific wiring loom I'd ever seen. I cut every wire out of that tin w#0re and started from scratch (a 6 month project). One switch on the panel was unmarked. I took the wire off of one terminal, followed it under the instrument panel, up the sidepost, across the headliner, across the spar carry-through, down the other headliner, down the other sidepost, under the instrument panel, to the other pole of the switch.

WTF????

Installer: "I'm retiring next year. Let's have a little fun with some future person."

 

[Bob Weber]

I was under the impression any upgrade must have an ICA that includes an interface diagram..

 

[JohnAJohnson]

When I install something, I first install it "on paper" to develop a battle plan and then wring it out. Then, when doing the actual install, I follow the paper, checking off connections as I do them. The final paper becomes part of the airplane's permanent record. I've been using Powerpoint for lack of anything better. Here's an example of a recent IFD540 installation:

 

[Bell206]

I was under the impression any upgrade must have an ICA that includes an interface diagram..

ICAs are only required for major alterations/repairs and above. But given the current guidance on ICAs there is no specific requirement for diagrams. I've seen ICA development/approval fall across a wide spectrum as it is very subjective to the developer and ASI/DAR that approves them. In general, most electrical alterations I've installed or seen installed fall under a minor alteration.

 

[Bob Weber]

When I install something, I first install it "on paper" to develop a battle plan and then wring it out. Then, when doing the actual install, I follow the paper, checking off connections as I do them. The final paper becomes part of the airplane's permanent record. I've been using Powerpoint for lack of anything better. Here's an example of a recent IFD540 installation:

View attachment 78665 View attachment 78666 View attachment 78667

This is the way I was taught, I started installing complete systems in brand new 340A's in the early eighties. From these projects, to the 441 -10 upgrades at Weststar, and every one of the major and minor ones in between, and since, I provided a working copy of the interface prints as an added feature for their dollar.
Today, I focus solely on assisting in troubleshooting and repair. One of the first questions I ask is whether the installer provided these very valuable documents, explaining how they can be used to eliminate significant time in troubleshooting. I advise all of my clients to require them with their upgrades, and how it is a sign of a level of workmanship and customer service that should be the norm, rather than the exception. Since I was young, thankfully, I was taught pride in workmanship, rather than just going thru the motions and doing the minimums.

 

[Bell206]

how it is a sign of a level of workmanship and customer service

I was taught pride in workmanship, rather than just going thru the motions and doing the minimums.

FWIW: I agree. It was the same way I was taught. However, complying with the “minimums” is not necessarily a function of a mechanic’s workmanship or customer service, but rather a function of what the owner wants or will pay for. And in a number of cases, the owner will only pay for the minimums. Just read some posts on POA for examples. However, in my experience, regardless if the job is performed to a minimum standard or beyond, the workmanship or customer service of most competent mechanics never varies.

 

[James331]

This is what comes to mind after reading OPs title

 

[Bob Weber]

FWIW: I agree. It was the same way I was taught. However, complying with the “minimums” is not necessarily a function of a mechanic’s workmanship or customer service, but rather a function of what the owner wants or will pay for. And in a number of cases, the owner will only pay for the minimums. Just read some posts on POA for examples. However, in my experience, regardless if the job is performed to a minimum standard or beyond, the workmanship or customer service of most competent mechanics never varies.

The vast majority of my work included working prints, with notes, and few pennies spent in order to include this valuable time saver by way of copies is just how customer service is provided when I roll.

I've always associated my self with shops that held this level of service, I can't count the number of clients I developed after they came to me with the issues the installer that under bid us by a couple thousand could not resolve, and no working prints to go by.

Generally they spent far more than they saved.

 

[Bell206]

my work included working prints, with notes, and few pennies spent in order ... by way of copies

associated my self with shops

the installer that under bid us

Just to clarify, are you talking about making copies of existing diagrams and schematics and giving them to your customers? If so, then by all means I would provide copies. Unfortunately, the majority of my electrical-avionics installations had zero existing diagrams save for the generic ones that may come with new equipment. Any drawings had to be developed/drawn/printed by me via x-number of man hours which didn't cost a "few pennies." Most GA owners will not pay for that time if it's not required. But considering you mention "shops" and "bidding" issues, I believe we are discussing two different facets of the industry as I never bid on any work nor did I have a dedicated shop.

 

[Bob Weber]

If you never bid on work, and work independently, no problem, I've lived in a different environment.

The client was charged a bit more, but the entire package delivered was superior. The delivered product included training in flight operation, flight checks of the systems and autopilot response with the pilot, training in the software quagmire, and of course a nice big beautiful three ring binder with all the required paperwork including the print copies we burned, and then made notes all over them of connection locations and such while accomplishing the work.

So many have come to me after choosing the wrong installer, spending far more than the difference in bids.

Today I do my best to educate owners to require the added amenities, they are far cheaper.

 

[Bob Weber]

I reread this and smile, here is another story about an install that could well have gone bad...
http://fly.twincessna.org/forum/viewtopic.php?f=4&t=7260&p=58383&hilit=hall+of+flame#p58383