Apparent tachometer cable issue, what is possible/legal in the meantime before it is fixed ?

Dan Thomas said:
Got a fluorescent light? See what the tach says when you get it up close to the light. Set it to two-blade and it should say 3600.
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I tried that once, per the directions. It checked properly against the light.
 
Dan Thomas said:
Well, the parts catalog and the service manuals both deal with it. Like I said, Cessna specifies what lube to use on the cable itself. They tell you to pull it out, clean it lube it, and reinsert it in its housing.

Is that good enough for you?
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Which cessnas? Give me a model, I'm legit curious.
 
pfarber said:
Which cessnas? Give me a model, I'm legit curious.
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Did you not see the Dan’s post? He clearly gave you a reference from the Instruments and Instrument Systems chapter of a 172 MM. He actually pasted a chunk of the 172 manual that address it. It’s also noted in the troubleshooting section of the same manual. You’ll find references for this in a number, if not most of the old airplane MMs. It’s also referenced in plenty of non regulatory publications. It’s become somewhat of standard practice for mechanics.
I dropped off a twin at a fancy maint shop for annual recently. It had a bouncy tach. The first thing the shop lead said was that they would pressure lube the cable. They did, and it fixed it. It’s what we do as a first step usually.
I honestly don’t understand why this is so hard to grasp.
 
pfarber said:
Which cessnas? Give me a model, I'm legit curious.
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I knew you'd argue that, so I posted an example in post #36. That was from the '69-'76 172 manual. The other Cessna manuals say exactly the same thing.

You can do a search yourself. Just Google "Cessna 172 service manual" and look for a .pdf. There are many versions of almost all the models on the net, and there are various Piper manuals, too. Then there is the FAA's AC43-13-1B and 2B, a thick book full of stuff intended for use on airplanes that have inadequate or nonexistent service manuals. It's full of FAA-approved information. It's a .pdf on the FAA's site. Comes in paper, too. There are a whole mess of other ACs, Advisory Circulars, all available on the FAA's website. The FARs are there, and FAR 43 specifically deals with maintenance. FAR 23 deals with the standards of construction for our little airplanes, but it was recently revised and a whole bunch of stuff moved into AC23-17C. Then there are the A&P textbooks, the AC65 series. Jeppesen and others publish better versions, though. Another good book is Aircraft Systems for Pilots, by Dale de Remer. Only in paper. A good way to start the basics.

You need to start educating yourself instead of challenging everything some licensed and experienced mechanic says here. You can play stump-the-chump all you want but you'll always lose.
 
I have two independent tachomters. The "legal" one is the MVP-50 which picks off the pulses from both magnetos (it will tell you if one fails). The backup is the JPI 830 which while isn't supposed to be my primary instrument, I might be inclined to use. It uses an inductive sensor that screws into an inspection plug hole on the right mag.
 
Dan Thomas said:
Got a fluorescent light? See what the tach says when you get it up close to the light. Set it to two-blade and it should say 3600. Unless you're in an old 50-Hz area. Don't know if there are any left.

No fluorescents? A neon indicator light will work if you're real close. Old deep freezes had them as power-on lights. Or you could by an NE-2H neon lamp from an electronics shop and use, IIRC, a 22K ohm resistor in series with it and apply 110VAC.

Much easier to find a fluorescent light.
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Surprisingly more countries than I thought
https://www.school-for-champions.com/science/ac_world_volt_freq_list.htm#.Yu0--iVq3YU
 
Dan Thomas said:
knew you'd argue that, so I posted an example in post #36.
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On mobile posts aren't numbered. So post #xx doesn't do much, and no, i am not counting.

I have the 100 series SM on my phone so ill take a look.

As an aside, if your skin is so thin that being asked a question is arguing then it might be time to seek counseling.

Ninja edit not in the 100 series SM. Its not OCRd so i cant search it, but its not in ch 12 or 16.
 
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unsafervguy said:
Surprisingly more countries than I thought
https://www.school-for-champions.com/science/ac_world_volt_freq_list.htm#.Yu0--iVq3YU
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Yes.

Most places/people are 50Hz. Exceptions are mostly where development was very strongly US influenced such as Japan and the Philippines.

Highlights:-
60 Hz - USA, Canada, Philippines, Mexico, Brazil, some Japan, Taiwan.
50 Hz - All of Europe, China, India, Pakistan, Australia, Russia, some Japan, Argentina.

https://en.wikipedia.org/wiki/Mains_electricity_by_country

4.5 pages 60 Hz
13.5 pages 50 Hz

Switched mode power supplies and crystal oscillators have made a lot of it irrelevant. Even quite big stuff can now run through solid state converters. Like countries!

International interconnectors can be DC to remove from the link any requirement to match/synchronize. Solid state conversion used at both ends. So international 50Hz-60Hz links are no issue.

e.g https://en.wikipedia.org/wiki/HVDC_Cross-Channel
I guess the 1961 version was DC - "This scheme was equipped with mercury-arc valves (tubes), each having four anodes in parallel." - sounds exciting.
 
pfarber said:
if your skin is so thin that being asked a question is arguing then it might be time to seek counseling.
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FWIW: I don't think it has anything to do with "skin" thickness but more on the level of your so said maintenance experience. Between this thread, the wing tip thread, and a number of other previous threads, your level of actual maintenance experience appears rather thin. It shows. Trust me. So if you actually have an A&P ticket perhaps you should brush up on the basics like how to find maintenance procedures in a manual or work under the supervision of an experienced A&P who could help you with this. :rolleyes:
 
pfarber said:
Ninja edit not in the 100 series SM. Its not OCRd so i cant search it, but its not in ch 12 or 16.
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In the '63-'68 100 series manual, it's on page 27 of Chapter 16:

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In the 1962 and prior 100 series manual, it's on page 19 of Chapter 16.

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In most other Cessna manuals, instruments are covered in Chapter 15.
 
Dan Thomas said:
Got a fluorescent light? See what the tach says when you get it up close to the light. Set it to two-blade and it should say 3600. Unless you're in an old 50-Hz area. Don't know if there are any left.
Much easier to find a fluorescent light.
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Most of the world is 50 Hertz. Only North and South American are 60 Hertz.

FYI, model airplane optical tachs are MUCH cheaper. :D
 
Pinecone said:
Most of the world is 50 Hertz. Only North and South American are 60 Hertz.
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And not even all of South America :). And most countries are 220-240 volts as well (I'm originally from two of those countries).

And don't get me started on power plug standards, styles, and usages… (if only every country used the Australian-style plugs you can also find in places like Argentina).
 
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UOTE="Bell206, post: 3291390, member: 31758"]FWIW: I don't think it has anything to do with "skin" thickness but more on the level of your so said maintenance experience. Between this thread, the wing tip thread, and a number of other previous threads, your level of actual maintenance experience appears rather thin. It shows. Trust me. So if you actually have an A&P ticket perhaps you should brush up on the basics like how to find maintenance procedures in a manual or work under the supervision of an experienced A&P who could help you with this. :rolleyes:[/QUOTE]

This is hilarious. I do post the FAR and i do cite a manual and yet the old heads (aka the randos on the internet) never seem to have a repaonse other than resort to attacking me personally.

Yes, your thin skin is translucent at this point.

What part of the FAR was i wrong about? Nothing but a personal attack.

What part about the SM was i wrong about? Nothing but a personal attack.

I seem to be putting up actual documents and substantial discussion and others just make uninformed posts and try to belittle me.

Here's a twist:. Prove me wrong. So far its just randos saying 'i know more' yet the proof you/they do is as thin as your skin.
 
Where did anyone argue with you over your FAR 91.205 citation? There was nothing wrong with that. Your mistake was in implying that mechanics had no legal right to disassemble a tachometer cable.
pfarber said:
Id like to know what references are used for this remove the tach cable incantation.
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Incantation. Implies witchcraft. It's a pejorative term, a slur. You have a history of doing that. You have never seen it in a service manual, so you figured you had that covered. You didn't and I posted excerpts from Cessna's maintenance manuals, manuals approved by the FAA, manuals referred to here:

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What part of the SM were you wrong about? You said you had the 100 series manual but you couldn't find the tach cable servicing in Chapter 16, so I found it in that manual--two versions of that manual--and posted it.
 
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pfarber said:
Prove me wrong.
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That’s the easy part. We collectively have many times with actual references which goes back to your 1st posts on PoA. Are you always wrong, no. But you continue to argue your opinions as fact which it is not in the context of most everyday aircraft maintenance.

I think Dan took care of the answers to your FAR and manual points. Just because you can’t find those procedures in the manual doesn’t mean you’re correct. But since you insist to call out the “randos” --whatever that means-- how about we go to your previous wingtip post?

: pfarber: I would hazard to guess that since the early 2000s the number of OJTs working on hours is less than 1%.. more like .001%. They just don't last long enough to complete the hours or cannot find a shop wanting the liability.
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Don’t know where you get your information put it’s a lot higher than those figures. I know of a number of operators/shops that are hiring A&P apprentices. Even Cessna has started an apprentice program due to the shortages. If things continue on their present course I think that percentage will increase to over 30% in the next 3 years due to the shortage of qualified mechanics. But what do I know since I’m only part of a group assisting several individuals who are using the OJT method to obtain their A&P.:rolleyes:
pfarber: Ive seen logs that go back for 70 years on jillions of AC and not one supervision sign off.
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So, how do you differentiate a “supervised” maintenance sign-off from a regular sign-off? Technically there is a method to separate them out but it not used much in the Part 91 world for simplicity sake. Is it that particular method you are looking for to find "supervised" sign-offs? I used it a lot during my owner-assist maintenance days and continue to use it when needed even today.
pfarber: Why would a sane AnP play russian roulette with two rounds on the revolver?
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As to you not knowing any A&P that supervises work my guess is that you don’t live in those circles. Perhaps you only work 121 or something. However, myself and a majority of other mechanics in my world, especially around the GOM, have been signing off supervised work on “jillions” of aircraft. Personally I’ve been signing off supervised work since the 1st day I got my ticket and continue through today as that is how I keep my ticket valid. Just because you don’t see it doesn’t mean its not as you submit. Maybe you need to get out more?

Regardless if you don't want to believe what me and other longtime, experienced A&Ps state on PoA so be it. I just call it as I see it.;)
 
woywoyboy said:
And not even all of South America :). And most countries are 220-240 volts as well (I'm originally from two of those countries).

And don't get me started on power plug standards, styles, and usages… (if only every country used the Australian-style plugs you can also find in places like Argentina).
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MOST of SA. Actually, IIRC, only parts of Brazil are 220.

And 220 is not always 220. Most of the world, it is like our 110, a hot and a neutral. But Philippines is two 110 volt legs, no neutral. Like US 220.

Japan is VERY odd (in many ways), but electrically, they are 100 volts, 50 Hertz.
 
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