New 170B owner

How to keep the Cessna 170 flying and airworthy.

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goodair
Posts: 49
Joined: Wed Jul 25, 2018 5:32 pm

Re: New 170B owner

Post by goodair »

Update. New/overhauled 20 amp generator installed. Matching Zeftronics regulator also. Someone had cut the gasket previously but i replaced the whole thing by removing the tach drive. Three nuts, takes 5 minutes. For a couple bucks did the tach drive seal also. Flashed the field and this blew the 20 amp fuse, so be carefull with that. Will disconnect regulator and flash directly from battery next time. Not sure why that happened. Anyway, it comes online right about 1300 or 1400 rpm and charges nicely. Replaced nav and landing lights with led and loads are very reasonable now.

I did find out why this thing failed. When the previous owner installed the new starter, he left a clamp on the tach drive cable that used to support the pull cable for the starter. This clamp must have migrated down the tach cable and eventually came to rest touching the armature terminal. Done shorted it out. I have rotated the terminals to where they show in the manual, not directly at the top like they were. I didnt see this as the terminals were hiding between the mags up on top.

I have noticed the old wire in our 54 is getting to the point it needs replacing. I put new 8 guage wire forward of the firewall for the ARM and will pull new wire through to the buss at our next annual. Question.......can we remove the soldered fuse assemblies and put in CBs without any certification issues? Do we even need a 337, or is replacing a circuit protection device with a better more modern unit that is TSOed just a log book entry. I know this has been done many times before. What are folks doing paperwork wise. To consider this a "modification " of our electrical system would be a stretch in my opinion as it is functionally identical.

The generator/regulator swap was not a difficult chore. Good for an afternoon or plan on a day if you are alone like me and this includes cowl on and off and general cleanup. I would not have needed the regulator if the one installed was the correct part, and not the 50 amp one.

Use a small magnet when putting the nuts and washers on the studs for the generator. If you dont, when dropped they will fall right inside the generator case causing much cussing and extra work. Ask me how i know.
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gfeher
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Re: New 170B owner

Post by gfeher »

Nice write up. Thanks for the update and tips.
Gene Feher
Argyle (1C3), NY
'52 170B N2315D s/n 20467 C-145-2
Experimental J3 Cub Copy N7GW O-200
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GAHorn
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Re: New 170B owner

Post by GAHorn »

goodair wrote:... Question.......can we remove the soldered fuse assemblies and put in CBs without any certification issues? Do we even need a 337, or is replacing a circuit protection device with a better more modern unit that is TSOed just a log book entry. I know this has been done many times before. What are folks doing paperwork wise. To consider this a "modification " of our electrical system would be a stretch in my opinion as it is functionally identical.....
I believe you'll find all sorts of opinions on this one.... Personally, I opine that it's a minor alteration which should be performed/supervised by an A&P and reference AC43, 13B-1B, Ch 11, Section 4 - Circuit Protection Devices as being followed in replacing fuses with Circuit Breakers, and reference the Mfr and PN of the CBs. My own airplane (which was modified before I acquired it) has a logbook entry that describes the entire electrical system being replaced along with it's Circuit Protection Devices per AC43.
At a later point in time however, Whelen Strobes were added and the electrical system and Circuit Protection was again addressed in the wording on a Form 337 referencing the same AC43, and quoting Ch's 4, 5, 11, and 15 which address Circuit Protection Devices, Wire Ratings, Clamping and Grounding. The airplane was twice inspected by FAA Maintenance Inspectors (for a different reason regarding the parking brake disabling) and they did not question the records even tho' they were noticed.

Circuit breakers are such an improvement over fuses that if done in accordance with good practices I doubt you'll find anyone to criticize the alteration. Fuses are difficult to replace in flight, at night, and are more subject to vibration and corrosion failures. Try finding that "cap" after it falls below the floorboards at night.

BUT... remember....to FORGET that old rule about resetting a CB in flight "one time"... as that's horse-biscuits! If a breaker OR fuse "POPS" in flight.... do not reset it at all unless you simply cannot complete the flight to a safe landing without that circuit! Fuses/C.B.s protect the WIRING. If the CB "POPS" ...it's because there's a SHORT somewhere and the last thing you need in-flight is an electrical fire that started because a wire went incandescent when that CB lost it's calibration due to resetting it to a shorted wire which carried more current than what it was rated for. Get on the ground somewhere and that's where you want to troubleshoot the problem...NOT in flight.

Also, be certain to inspect the entire wiring circuit for damaged or overheated wiring insulation, clamps, connectors, and other devices in that particular circuit. Just because the CB was successfully reset is not by itself a proper inspection. :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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N2625U
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Re: New 170B owner

Post by N2625U »

Reference the resetting a circuit breaker. 20 some years ago my airline's procedure when a circuit breaker popped was to reset it once. At cruise altitude the FO's windshield heat circuit breaker popped. We reset it and about 5 minutes later the cockpit filled with smoke and we put on the O2 masks as per memory items, declared an emergency and landed at the nearest suitable airport. At times it was difficult to see the instruments and the landing was in IMC conditions outside and inside, opening all the air vents did help somewhat. This is not something you want to do on a regular basis. After that my airline changed the procedure to when a breaker pops don't mess with it! It was an RJ and we were at FL350 when it popped. Also the training dept added this to our regular sim checks for a couple of years.
Keep your speed up, Blackhawk on final behind you.
goodair
Posts: 49
Joined: Wed Jul 25, 2018 5:32 pm

Re: New 170B owner

Post by goodair »

Another interesting development. I replaced the nav lights with LEDs. I will ignore the whole legal mumbo jumbo for now about why and how the faa is dealing with these. Bottom line is that with a 20 amp generator every little bit helps. BUT, we have developed some seroius static in the intercom. We are currently using the internal intercom with our Garmin com radio. It now sounds like someone is hitting the squelch button every fewnseconds. Turn the nav lights off and it goes away. Put the standard bulbs back in and no issues. So, these are the colored bulbs from spruce and are plenty bright even through the colored lenses. Way brighter than standard. But with the static off they come. Inwill need to see if i can send them back. 50 bucks for three, but i wont do this again. This is the second aircraft i have tried LED nav bulbs on and both times there was interference and static. Anyone have similar experiences?
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Bruce Fenstermacher
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Re: New 170B owner

Post by Bruce Fenstermacher »

Interesting on the LED noise. Wonder if it's just one. I'd have to try them out individually to see. Also for that money Spruce or their supplier may have a fix for you.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
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Macunix
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Re: New 170B owner

Post by Macunix »

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Last edited by Macunix on Sat Jan 02, 2021 9:05 pm, edited 1 time in total.
goodair
Posts: 49
Joined: Wed Jul 25, 2018 5:32 pm

Re: New 170B owner

Post by goodair »

I agree that somehow the electrical components in these LED bulbs can and do cause this interference. I guess we really can not bust on the FEDS for not embracing this technology, if it doesn't work. It is a bummer that the manufacturers of these bulbs are not addressing the specific needs of aviation and making a bulb that will actually work without interference. I know it works for some as many have them installed, and yes you could solve the problem with a 500 dollar Whelen fixture, but i need just a light bulb. We have a go cart on MARS! I think we should be able to make a light bulb that doesn't do this. I have also tried another set of bulbs from another manufacturer on a more modern aircraft with properly shielded wiring with the same results, so it is something in these bulb electronics.
Macunix
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Re: New 170B owner

Post by Macunix »

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Last edited by Macunix on Sat Jan 02, 2021 9:04 pm, edited 1 time in total.
hilltop170
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Re: New 170B owner

Post by hilltop170 »

I have AeroLEDs installed and have never had any interference of any kind in com or nav radios, intercom, ADF, or cell phone bluetooth from the audio panel, in either pulse-light mode or on-continuously.

Maybe that's the difference between "STC'd and non-STC'd" LEDs. Correction, "PMA'd and non-PMA'd"
Last edited by hilltop170 on Wed Jan 16, 2019 12:08 am, edited 1 time in total.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
goodair
Posts: 49
Joined: Wed Jul 25, 2018 5:32 pm

Re: New 170B owner

Post by goodair »

I have not seen any AeroLED replacement bulbs that are STCed. You can purchase an STCed replacement assembly as a whole unit, but we already have the piggyback strobe set up and this would not make sense. If AeroLED makes an STCed LED bulb for nav lights, I have not seen it. Am I missing something?
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brianm
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Re: New 170B owner

Post by brianm »

I've had good luck with these: https://www.ledlight.com/s25-36-super-b ... light.aspx

No noise. Your mileage may vary. My plane has about the simplest possible avionics setup, so maybe I've just been lucky.
Brian M
N2669V - '48
hilltop170
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Joined: Sat May 06, 2006 6:05 pm

Re: New 170B owner

Post by hilltop170 »

goodair wrote:I have not seen any AeroLED replacement bulbs that are STCed............. If AeroLED makes an STCed LED bulb for nav lights, I have not seen it. Am I missing something?
Hmmmmmm

Bad assumption on my part, PMA'd but not STC'd.

I checked and it was a logbook entry only.

I had 4 other STCs installed at the same time, assumed they were one of them.

Thinking about it, they are just PMA'd replacements so that makes sense.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
goodair
Posts: 49
Joined: Wed Jul 25, 2018 5:32 pm

Re: New 170B owner

Post by goodair »

Ok thanks a bunch. I will take another look. I saw their replacement bulbs and the 12 volts said exprimental only, but i need to give them a call. I am really not worried about the pma or faa thing, as long as they WORK:)

Cant turn off the nav lights everytime you need to talk on the radio. If you have had good luck with them with our old wiring, then i need to look into them.
hilltop170
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Re: New 170B owner

Post by hilltop170 »

I have AeroLEDs on 3 different 1950s Cessnas, same experience with all 3, no noise.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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