NotarPilot Posted August 7, 2020 Report Posted August 7, 2020 Is is kosher to install a non-PMA’d, non-TSO’d dome light, purchased from Spruce, inside a TC’d airplane under a minor and if not, why not? Also, if a rocker switch is installed on the armrest to act as the on/off switch, does that rocker switch need any kind of approval assuming it is wired to an inline fuse or circuit breaker? Or can it be any old rocker switch bought from Radio Shack (R.I.P.)? Asking for a friend. Also, for the purpose of this completely hypothetical scenario, both the dome light housing and panel where the rocker switch is mounted are made of aluminum. Discuss. Quote
bradp Posted August 7, 2020 Report Posted August 7, 2020 Get any PMA or TSOd dome light and install it as a minor mod with a logbook entry. This is the single best major minor 337 etc presentation I’ve encountered. 1 Quote
47U Posted August 7, 2020 Report Posted August 7, 2020 https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-77.pdf There’s a logic tree on the last page of this AC. As long as you use approved methods and materials (your A&P might determine the dome light meets approval after inspecting its design and construction). Otherwise, use mil-spec wire, switch, and circuit protection and you should be able to get it signed off as a minor modification. If you can convince your A&P. tom Quote
NotarPilot Posted August 7, 2020 Author Report Posted August 7, 2020 5 hours ago, bradp said: Get any PMA or TSOd dome light and install it as a minor mod with a logbook entry. This is the single best major minor 337 etc presentation I’ve encountered. I watched webinar and it doesn’t answer the question but thank you. Quote
NotarPilot Posted August 7, 2020 Author Report Posted August 7, 2020 4 hours ago, 47U said: https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_120-77.pdf There’s a logic tree on the last page of this AC. As long as you use approved methods and materials (your A&P might determine the dome light meets approval after inspecting its design and construction). Otherwise, use mil-spec wire, switch, and circuit protection and you should be able to get it signed off as a minor modification. If you can convince your A&P. tom This looks like a better explanation, thanks. My interpretation is that you can depending on what you consider a change in weight? Does it have to be appreciable? Otherwise a sheet of paper technically is a change in weight in the absolute literal sense. I don’t see how a dome light affects performance or any other qualities/characteristics. Assuming it’s made of aluminum and not plastic I would think it doesn’t need any burn certification. Quote
bradp Posted August 7, 2020 Report Posted August 7, 2020 So the answer is it wouldn’t be considered a major mod with regard to any of the criteria. But it would lack approved data. So no you can’t. Quote
jaylw314 Posted August 7, 2020 Report Posted August 7, 2020 49 minutes ago, bradp said: So the answer is it wouldn’t be considered a major mod with regard to any of the criteria. But it would lack approved data. So no you can’t. If it's not a major mod, it only needs acceptable data, not approved data. That pretty much means at the discretion of the A&P, although there's always the unwritten question of whether the next IA will agree at annual. 2 Quote
47U Posted August 7, 2020 Report Posted August 7, 2020 56 minutes ago, NotarPilot said: 5 hours ago, 47U said: This looks like a better explanation, thanks. My interpretation is that you can depending on what you consider a change in weight? Does it have to be appreciable? Consensus on how changes in weight constitute a major alteration have evolved. Major alterations change the maximum gross weight, and/or forward/aft C.G. limits. Have your A&P recalculate the new empty weight and C.G. arm change as a minor alteration. In all likelihood, since you’re only talking about ounces vs. pounds, he’ll sign it off as ‘negligible’ change to w&b. 1 minute ago, jaylw314 said: If it's not a major mod, it only needs acceptable data, not approved data. That pretty much means at the discretion of the A&P, although there's always the unwritten question of whether the next IA will agree at annual. Yup, talk to your A&P first. And/or your IA, if they’re different people. tom 2 Quote
NotarPilot Posted August 7, 2020 Author Report Posted August 7, 2020 6 minutes ago, 47U said: Consensus on how changes in weight constitute a major alteration have evolved. Major alterations change the maximum gross weight, and/or forward/aft C.G. limits. Have your A&P recalculate the new empty weight and C.G. arm change as a minor alteration. In all likelihood, since you’re only talking about ounces vs. pounds, he’ll sign it off as ‘negligible’ change to w&b. Yup, talk to your A&P first. And/or your IA, if they’re different people. tom I think I have one willing to do it. You guys have been very helpful. Quote
bradp Posted August 7, 2020 Report Posted August 7, 2020 Sorry I confused my self between data types. Could the A&P generate the acceptable data? Quote
Floyd Posted August 7, 2020 Report Posted August 7, 2020 What does a AC for Part 121 have to do with Part 91? Quote
jaylw314 Posted August 8, 2020 Report Posted August 8, 2020 5 hours ago, bradp said: Sorry I confused my self between data types. Could the A&P generate the acceptable data? "acceptable" usually comes from the guidelines in AC 43.13-1b Edit: oops, technically 43.13-2b. Quote
larryb Posted August 8, 2020 Report Posted August 8, 2020 How about an led battery powered closet light from amazon? Portable and no paperwork required. And no risk of running down the ship battery and killing your new Concorde battery. 3 Quote
carusoam Posted August 8, 2020 Report Posted August 8, 2020 So you want to add a dome light... There are many M20s with dome lights... Copying one exactly will give all the data you want to have... Supplying your own aviation parts and handing them to your mechanic for install and documentation can work as well... The next test comes up at annual... Does it look like you installed it yourself, or does it belong there? Does it use an LED? Does it use a PWM to dim the LED? Does it only cost a few bucks... Is it protected by a CB switch... So... if your mechanic we’re to install this... he would probably run the circuit from an existing CB switch that handles interior lights... The hard part is running wires up to the dome.... Wait... aren’t there lights and switches that do this already, and are in place already? How complex do we want this to be? What did I miss? PP thoughts only, not a mechanic... Best regards, -a- Quote
NotarPilot Posted August 8, 2020 Author Report Posted August 8, 2020 18 hours ago, larryb said: How about an led battery powered closet light from amazon? Portable and no paperwork required. And no risk of running down the ship battery and killing your new Concorde battery. It has that now. I don’t like it. Quote
NotarPilot Posted August 8, 2020 Author Report Posted August 8, 2020 18 hours ago, carusoam said: So you want to add a dome light... There are many M20s with dome lights... Copying one exactly will give all the data you want to have... Supplying your own aviation parts and handing them to your mechanic for install and documentation can work as well... The next test comes up at annual... Does it look like you installed it yourself, or does it belong there? Does it use an LED? Does it use a PWM to dim the LED? Does it only cost a few bucks... Is it protected by a CB switch... So... if your mechanic we’re to install this... he would probably run the circuit from an existing CB switch that handles interior lights... The hard part is running wires up to the dome.... Wait... aren’t there lights and switches that do this already, and are in place already? How complex do we want this to be? What did I miss? PP thoughts only, not a mechanic... Best regards, -a- It actually has an existing dome light already. I wanted to change it with two dome lights (See image) and wired to to two different rocker switches, one for each side, pilot and copilot. I wanted to make it look nice so cheap Walmart battery powered options are not what I would like there permanently. I would even like to maybe put these Aveo lights in the rear for passengers. 1 Quote
carusoam Posted August 8, 2020 Report Posted August 8, 2020 Very easy tech add on... Removing/replacing the ceiling panel will be the hardest part... The Aveo guys have good products used on Mooneys... Best regards, -a- Quote
NotarPilot Posted August 9, 2020 Author Report Posted August 9, 2020 3 hours ago, carusoam said: Very easy tech add on... Removing/replacing the ceiling panel will be the hardest part... The Aveo guys have good products used on Mooneys... Best regards, -a- Yes they do but unfortunately some of their products are not TSO’d and I’m trying to figure out if they really have to be. And you’re right, it is a very simple add on so I don’t see much of an issue. But I want everything to be kosher in my plane and prefer to avoid issues in the future, Quote
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