The International Cessna^® 170 Association

Is there any good reason to keep the overhead speaker nowadays? Other than originality? I have my headliner out replacing the interior and thought I might remove it. It's not connected to anything.

If you don't want it someone certainly will. But, ( ) the speaker is attached to the cabin roof and to the speaker housing which helps support the speaker housing which in turn holds the headliner bows. So now that you're there you can attach some wires to the speaker and run them down the fwd door post for future or maybe present use.

As Jim alluded to it is not that easy to remove the speaker. As he stated the speaker hold up the surrounding aluminum baffle. Your headliner bow is held up by the baffle.

Removing the speaker and the baffle would required you to find a suitable replacement for that front bow which stretches from one side to the other. Not impossible, but not that easy either.

I don't have a correct speaker and made instead a bracket out of folded aluminum to replace the speaker and hold the baffle in proper place.

I see what you mean once I took it apart. I do have a speaker out on the new audio panel we are putting in. I'll have to test the speaker to see if it still works. I think I will just run a new wire (#31) and hook it back up to the audio panel when we install it.

If it does not work it can be made to work. Even if it does not work and you don't want to overhaul it you might want to keep it or give it to someone who will use it. They are an odd size and can not be found. And then if you did find one you'd have to drill and tap the magnets. What ever you do, if it is the correct speaker, you have the equivalent of hens teeth. Don't through it away.

You can remove the speaker and leave the mounting frame. My speaker has been relocated to the LH wing root but the frame is still in place, supporting the headliner.

Found a good source for the replacement of the head liner bows. Mind had rusted away and wasn't a good option to put back with a new headliner. So my fishing tackle store had some blank fiber glass rods about a 1/4 in in diameter and they work just great. No rust stains on the headliner and you can cut them to your length.

i found a used replacement 4ohm speaker. ended up mounting it to the outside of the frame instead of the inside. it was just a little too tall to fit up against the roof. in fact the old one touches the roof skin anyway.
i cleaned up the lights and the plastic cover, fixed the interior light. speaking of interior light, has anyone put a LED version in there?

Part 43, Subpart D requires that a person performing an annual or 100 hour inspection shall inspect the radio and electronic system for "defects" and "proper operation" of wiring. This means your speaker MUST be in working order.

Also, be aware that many "alert" and other systems rely upon a cabin speaker. TSO-C195b addresses this : "The voice message will be annunciated over a cockpit speaker and through a headset/helmet at a volume adequate for clear understanding at high cockpit noise levels, but not excessively loud at low noise levels...."

Unless your aircraft equipment list is accompanied by a MEL which proscribes actions to compensate for the loss of the audio from the speaker, you must have a cabin/audio speaker on board and it must be operational.

FAR 135 requires a backup to the headset in the form of a speaker, and headsets must also be backed up with a handheld microphone... so to be sensible about operations in controlled airspace... you should probably repair your speaker.

Be alerted that the upcoming ADS-B will also likely require a cabin speaker.

That info is interesting George. I had heard it previously, but had forgotten. I operated my plane for many, many years without a workable speaker and not one of the 7-10 different AI's ever mentioned it or checked it as I always had an intercom system shortly after purchasing my plane in 1989. Approximately 6-8 yrs ago I had an A&P help me rewire my avionics, adding a avionics panel, etc. We removed the bad speaker and replaced it with a new one, but he removed my microphone jack. Just goes to show there are a lot of things that probably don't get checked at annuals according to the FAR's.

George, none of the helicopters I've ever flown part 135, have had a cabin speaker or a microphone. Can you explain that? Or maybe, just maybe a speaker and a microphone is not required.

My 170 does not have a speaker. It is not on my equipment list.

I believe he is referring to what was IN your plane when they rolled it off the line.

100s of planes don't have anything for a speaker. Heck they don't even have a radio.

And there are a 100 other things I put ahead of this however I like having mine operational. Mostly because it was there and bothered me that it didn't work.

Even if a speaker was in your 170 when it left the factory, it can be removed. It is not a required piece of equipment. Actually most of the 170s had no radio when they left the factory. Radios where installed after delivery.

gahorn wrote:
Be alerted that the upcoming ADS-B will also likely require a cabin speaker.

Since the only ADS-B that MAY be required for our aircraft is an ADS-B OUT there is no speaker requirement. The ADS-B IN will not be required and even if used will not require a speaker as it just provides information useful to the pilot (i.e. WX, traffic etc.) it is not a warning system ala TCAS.

gahorn wrote: Also, be aware that many "alert" and other systems rely upon a cabin speaker. TSO-C195b addresses this : "The voice message will be annunciated over a cockpit speaker and through a headset/helmet at a volume adequate for clear understanding at high cockpit noise levels, but not excessively loud at low noise levels...."

I don't know what I am doing wrong but, I can't find that sentence or any sub part of it in TSO-C195B.

But even so, that TSO addresses Aircraft Surveillance Applications which is not required for the ADSB mandate.