LED replacements for interior "map" lights?

[Lance Murray]

Guys, I have been replacing bulbs for years. I have been doing it in 91, 135, and 121 operated aircraft. Many airplanes come with a bulb kit and pilots are expected to field replace a bulb. If a 135 pilot grounded an airplane because a bulb in the panel burned out he would be fired very quickly. I don't believe any inspector would care if you replaced a bulb anywhere on an airplane that you own and operate. If he does it is likely because you got his attention in another way.

[carym]

Guys, I have been replacing bulbs for years. I have been doing it in 91, 135, and 121 operated aircraft. Many airplanes come with a bulb kit and pilots are expected to field replace a bulb. If a 135 pilot grounded an airplane because a bulb in the panel burned out he would be fired very quickly. I don't believe any inspector would care if you replaced a bulb anywhere on an airplane that you own and operate. If he does it is likely because you got his attention in another way.

Lance,
I think the issue is replacing a bulb with something that the plane was not designed or specified to use, such as replacing standard incandescent bulbs with LED lights.

[smoss]

From a technical standpoint, is anyone using the Terostat sealant that is called for in the maintenance manual, or just clicking it in the light unit and sealing the gap with silicone? The stuff does not seem to be available in the U.S.

[Steve]

I don't use any sealant (but I live in TX, and any cooling airflow is good). Having said that, I did recently replace the speaker, which had a tear in the rubber annulus. I found a good (cheap) source for these if anyone else needs to replace them.

Steve

[Chris B]

I did recently replace the speaker, which had a tear in the rubber annulus. I found a good (cheap) source for these if anyone else needs to replace them.

Yes, please!

I am once again amazed by your online search skills...

Chris

[Chris B]

From a technical standpoint, is anyone using the Terostat sealant that is called for in the maintenance manual, or just clicking it in the light unit and sealing the gap with silicone? The stuff does not seem to be available in the U.S.

I recommend this DAP sealant:

Product page: link
MSDS (pdf): link
Technical bulletin (pdf): link
$11 at Amazon: link

This appears to be functionally equivalent to the Terostat sealant, and worked great for me. The gray blends nicely with the fixtures, and it is permanently flexible. Application is simple with a good caulk gun (you have to twist the bead 360 deg), and removing excess is easy since it is water soluble until the 'skin' forms.

Note that the Product Description on Amazon is wrong, as this does *NOT* contain silicon.

Chris

[smoss]

Thanks Chris. I will take a look at the Side Winder. Incidentally, my lights are currently sealed with clear silicone, as this is how the plane came when I bought it, and it appears was OEM. As well, every other DA40 I've been in also had the lights sealed with clear silicone. The terostat supposedly gets sandwiched under the light fixture, and I have no clue whether any of the planes I've been in had it in there in addition to the silicone bead. The stuff (per my web search) looks very much like plumber's putty--perhaps that would be a decent substitution as well.

[Cschobel]

Just attended an AOPA summit maintenance presentation. And the speaker, an A&P, said that the FAR's do not allow an owner to replace the map light bulbs. He says the FAR is old and needs to be rewritten but as of today, they must be replaced by an A&P.

Here is the only paragraph in regs that allow light bulb replacement.

(17) Replacing bulbs, reflectors, and lenses of position and landing lights.

[rwtucker]

I see that (17) is in "Appendix A -- Major Alterations, Major Repairs and Preventative Maintenance" but it refers to position and landing lights. Id did not see any mention of things like cabin lights, courtesy lights, door lights, lights in the "glove box" (my Dakota has one), etc.

This link says the pilot can make these repairs, etc. including to position and landing lights. http://teclineaerospace.com/maintenance ... ownerp.htm

I wonder where the confusion is coming from?

[Cschobel]

No confusion to me. But I have seen on this forum people say they have replace the map lights. Clearly they are not allowed by the FAR's. Only lights for position and landing.

I see that (17) is in "Appendix A -- Major Alterations, Major Repairs and Preventative Maintenance" but it refers to position and landing lights. Id did not see any mention of things like cabin lights, courtesy lights, door lights, lights in the "glove box" (my Dakota has one), etc.

This link says the pilot can make these repairs, etc. including to position and landing lights. http://teclineaerospace.com/maintenance ... ownerp.htm

I wonder where the confusion is coming from?