Annual Dilemma & Some Irony

[Sinistar]

Hi Everyone,

This is for a Cessna 182 we just purchased this summer. We had a few issues with our previous A&P [independent] so we sought out recommendations and are now working with new mechanic [a shop] . They found and repaired a few things and did an awesome job of scouring 44 years of logs and AD's and explaining everything to us. Our notable issues were related to mags (both). Now it mag checks and runs great!

Now for the dilemma and irony! In my first post to POA I inquired about removing some older non-functioning avionics and to shift the panel around to give us some room to permanently mount a tablet. We thought about the advice given here (which was generally against!) and decided to go for it. They said it shouldn't be too hard and the wires were long enough. And it seems the previous IA work was done quite well.

When I first saw the result, it was great, just what I expected and they went out of their way to make it easy for me to mount what I requested and leave us options.

But then the problem. The intercom and DME were no longer working - major bummer. He said they were working earlier. Since we went out of our way to try everything on the plane before the annual, we used and verified DME worked. The intercom was of course working. So we rolled the plane back in the hanger and said he would try and fix it and call back. He did call us back. He said if he can't figure it out we should fly it to his friends shop to have it repaired. I then asked if he would cover that cost and he said if he can't figure it out next week then he will not cover it.

Sorry for the long run up there. We feel they did good work. We also feel that their work left the plane in a much better state [mechanically] than when we flew it in! Now it wasn't cheap but we feel the bill was fair. However, w/r to avionics it is surely in a lesser state than when we brought it in. And the vibe: "If I can't figure it out it will be your problem." isn't what we expected given how everything else went.

Has anyone had this experience before? Any advice? Is this normal? Should we really have to cover this cost if he can't figure it out?

We respect A&P's and IA's. Nothing beats flying and it ain't happening without them.

 

[Tom-D]

Now you know why we have avionic shops. Most common FBOs are not equipped or trained to do radio work.

 

[GRG55]

I wouldn't even think of having the guys who help me with airframe and mechanicals start messing around behind the center stack of the panel. Pull and replace a gyro instrument, or an altimeter, sure...but not the radios or autopilot system.

 

[Fearless Tower]

Here's the thing about aging airplanes:

Everything was working great.....and then you had the shop do some work on the panel and you disturbed it. I started experiencing this with my Baron when we pulled the GNS 430 out to upgrade it to WAAS. Suddenly all kinds of gremlins started to pop up in the panel. In short, it isn't entirely unusual to have issues show up when the wiring in the panel is 'disturbed'.

That said, most shops I know would at least work with you to minimize the additional cost of tracking it all down. But, like Tom said above, you really might be better off having a full avionics shop troubleshoot the problem. They will be able to solve it quicker.

 

[Brad Z]

I'm not sure if you've owned an airplane before this one but the relationship between an owner and an A&P or shop is a little different than the relationship you might have with the dealership servicing your car. Unlike modern cars, there's a lot of unknowns involved in any sort of radio/wiring work. troubleshooting is very more involved, and it's quite possible that he didn't do anything wrong...yet the DME stopped working. It could be that the radio was never properly grounded but managed to make ground contact until the work was done.

Either way, sometimes you have to show up with a suitcase full of money, or find someone else to fix it. Not all mechanics are good at everything, and avionics work is specialized.

 

[denverpilot]

"He did call us back. He said if he can't figure it out we should fly it to his friends shop to have it repaired. I then asked if he would cover that cost and he said if he can't figure it out next week then he will not cover it."

If someone says they'll do something, and doesn't, and doesn't know how to (fly it to my friend's shop), and doesn't offer a refund after they make it worse...

Looks like you know exactly who never to hire again.

 

[airheadpenguin]

An airplane panel is a trip back in time. If we had it to build from scratch everything would be ethernet and IP but its not its a lot of D-sub based serial connections that were hand wired. The panel becomes a system of its own interconnecting various instruments to one another until it works together. I'm a 35 year old computer engineer by training, the only thing I can do when I look back there is be amazed by 2 things:

1) It hasn't started an electrical fire ... yet
2) A miracle was bestowed on my plane and it somehow all works ... today

Be happy that you know all of the boxes work and get the wiring taken care of, enjoy the plane you won't think about this in a few months.

 

[bnt83]

That's why I decided to remove my entire radio harness and build it for the radios I plan on flying with for the next 20 years then install the whole works in one shot. Legacy radio contacts and housings are inferior to newer designs IMHO

 

[Chip Sylverne]

One of the things I've come to learn is that a more often than not avionics installers take the install manual merely as a suggestion. I understand completely why shops prefer new installs, sometimes it's next to impossible to decipher what the previous guy did, much less why. Sure, the wiring and techniques may be 43.13, but the logic...if everyone did just did it by the book life would be sooo much simp!er.

Having said that, every time I go behind the panel of my bird I could kiss the guy who did the panel right on the lips. Everything is ordered and bundled correctly, logical, labeled and by the manuals. Even the connector pins are labeled at the end of each row on the backplate in sharpie so you don't have to go blind trying to decipher the pinout. There are shops and independent installers that do it right.

I'm sympathetic with your guy, but if he broke it he should fix it, unless it's his own gross error you should expect a bill.

 

[Sinistar]

I really appreciate the input.

We have owned one plane before (a 1946 Aeronca). I thought of it like it was part of the "great generation". No electrical!!! (except the ELT). My wife and daughter would fly on nice weekend mornings. I would hand prop it for them, annuals were so much simpler, 4.5gal/hr, beautiful restoration. And the older mechanics, especially independents seem to love those old planes and teaching you something along the way. Then it was time for the whole family to fly and we decided on a 182. We love the plane (we call it our Suburban). We needed to move on to another mechanic so went with a shop this time around based on recommendations. They seem to do great work.

You are so right about the car dealer vs A&P analogy. I was expecting a call saying "We've found all this, the bill will be..." and then show up and pay that bill. In this case the shop indicated what was wrong, mentioned part prices and gave an idea of labor but the bill was still a surprise...mainly because we just had no idea how much total labor beyond the base annual. I almost posted a few days back to see if I should be asking them to well...be like the car dealer and give the exact quote up front...but it doesn't sound like that would have went over to well????

Part of this is time too. I am just hearing news I don't want to hear (both availability and cost). He's just running into problems he didn't expect. One mistake I could be making is that in my industry (software and automation) if even one customer has an issue, we put resources on it at the cost of future development to solve the problem. Our customers often spend amounts in the same neighborhood as that of a 6-cyl aircraft annual. To us it just isn't right to leave it on a bad note, bad word of mouth, ever. Plus we usually learn something to make the product better. That ethic has been instilled into all of our team by a fantastic director who will probably retire one day soon. I figured in this industry you would also want that great word of mouth and might have to take a bit of loss here or there for the bigger picture.

I think my single biggest mistake, as mentioned, was not doing this work with a Avionics shop. Maybe our mechanic should have spoke up too - easy to 2nd guess now. I made the mistake of thinking (well, to be honest "expecting") it to be easier and that aviation equipment, wiring, etc were just way more robust.

 

[kyleb]

I really appreciate the input.


You are so right about the car dealer vs A&P analogy. I was expecting a call saying "We've found all this, the bill will be..." and then show up and pay that bill. In this case the shop indicated what was wrong, mentioned part prices and gave an idea of labor but the bill was still a surprise...mainly because we just had no idea how much total labor beyond the base annual.

I always asked my IA to call with a quote before he began on "new work". In other words, if the annual was supposed to be $750 (or whatever), and if he found anything that required repairs above and beyond the inspection, I needed to know the cost before he started on the repairs. That system worked well for me and the IA.

 

[Tom-D]

I always asked my IA to call with a quote before he began on "new work". In other words, if the annual was supposed to be $750 (or whatever), and if he found anything that required repairs above and beyond the inspection, I needed to know the cost before he started on the repairs. That system worked well for me and the IA.

I don't have any customers that wouldn't authorize me to repair as I go. Many of us IAs will tell you if you nit pick us on every nut, bolt, or screw you can go away.

 

[Tom-D]

OBTW, I've yet to move a piece of av gear that didn't cause other problems. the harnesses on some of this equipment is 50-60 years old you bend it you break it.
That's why I don't do radio work unless it is a strip and replace with new radios with pre-wired & pre-tested harnesses.

 

[weirdjim]

OBTW, I've yet to move a piece of av gear that didn't cause other problems. the harnesses on some of this equipment is 50-60 years old you bend it you break it.
That's why I don't do radio work unless it is a strip and replace with new radios with pre-wired & pre-tested harnesses.

I'll differ with Tom here, but only in the abstract. When I strip and replace with new radios, along with the radios comes a square piece of aluminum with a LOT of screw-type terminal strips on it. Every radio gets its own terminal strip. The terminal strips are then wired (with marked coded wires) to the other terminal strips. New radio? The old radio gets taken off the terminal strip and the new one gets put on. Doesn't work right? THe terminal strip is right out there in plain sight for voltmeter and other analysis instruments to figure out what went wrong. Wire it all up with no intermediate (terminal strip) connectors? You've got a colossal mess on your hands.

If if is a technique good enough for Boeing, it is good enough for CessBeePipMoo.

Jim

 

[Tom-D]

I'll differ with Tom here, but only in the abstract. When I strip and replace with new radios, along with the radios comes a square piece of aluminum with a LOT of screw-type terminal strips on it. Every radio gets its own terminal strip. The terminal strips are then wired (with marked coded wires) to the other terminal strips. New radio? The old radio gets taken off the terminal strip and the new one gets put on. Doesn't work right? THe terminal strip is right out there in plain sight for voltmeter and other analysis instruments to figure out what went wrong. Wire it all up with no intermediate (terminal strip) connectors? You've got a colossal mess on your hands.

If if is a technique good enough for Boeing, it is good enough for CessBeePipMoo.

Jim

IOWs you re-wire every thing. Not a bad idea, when the owner is willing to pay for it.
I can't afford to let the blue smoke out, I have no way to put it back.

 

[midcap]

IOWs you re-wire every thing. Not a bad idea, when the owner is willing to pay for it.
I can't afford to let the blue smoke out, I have no way to put it back.

I wonder how much somthing like that runs. I know it isn't exactly cheap in the marine world. Given that, since I was a marine tech for so many years, when ever I would buy a used boat that was older than 10-15 years or so, it would get all new wiring.

 

[mondtster]

I wonder how much somthing like that runs. I know it isn't exactly cheap in the marine world. Given that, since I was a marine tech for so many years, when ever I would buy a used boat that was older than 10-15 years or so, it would get all new wiring.

How much rewiring are you talking about here? All new wiring in the entire airplane or just new wiring for the avionics? All new wiring for a Cub is going to be much cheaper for a Cub compared to a Super Cub, and all new wiring in that Super Cub is going to be far cheaper than something like a high performance single or twin. I'd expect similar in the marine industry, where the price goes up accordingly with the level of complexity.

New wiring seems to be a rarity in the aviation world, even if most planes do need it. The cost is just too high in most cases.

 

[ircphoenix]

One mistake I could be making is that in my industry (software and automation) if even one customer has an issue, we put resources on it at the cost of future development to solve the problem. Our customers often spend amounts in the same neighborhood as that of a 6-cyl aircraft annual. To us it just isn't right to leave it on a bad note, bad word of mouth, ever. Plus we usually learn something to make the product better. That ethic has been instilled into all of our team by a fantastic director who will probably retire one day soon. I figured in this industry you would also want that great word of mouth and might have to take a bit of loss here or there for the bigger picture.

Also remember in your industry a new software team is a phone call or an email away so if the customer has a bad experience, they can pretty easily find someone else to work with.

With our planes, we're not so lucky. You're limited to mechanics on your field or traveling mechanics. If you choose to take your plane to another field with another mechanic, then you don't have an easy way home. It limits our ability to have market forces fix the ones that suck.

 

[GRG55]

How much rewiring are you talking about here? All new wiring in the entire airplane or just new wiring for the avionics? All new wiring for a Cub is going to be much cheaper for a Cub compared to a Super Cub, and all new wiring in that Super Cub is going to be far cheaper than something like a high performance single or twin. I'd expect similar in the marine industry, where the price goes up accordingly with the level of complexity.

New wiring seems to be a rarity in the aviation world, even if most planes do need it. The cost is just too high in most cases.

These old airplanes are like renovating an older home. You make the first cut in the wall to fix some plumbing or electrical, and the next thing you know the bathroom or kitchen is half-gutted and its a runaway...

I'm looking at the wiring FWF in my Aztec and there's lots of signs of insulation becoming brittle with age and heat. As an example, after paying to have several engine instrument issues repaired I can see why people give consideration to putting in a certified engine monitor and ripping out all the old cabling. It's just a matter of how much money can one spend prudently on an older airframe that is not worth all that much any more.

 

[coloradobluesky]

What do you drink? Scotch? Margarita? Beer? 200 proof vodka? Here Ill make you one...

 

[bluerooster]

Now you know why we have avionic shops. Most common FBOs are not equipped or trained to do radio work.

Oh good lord!! It aint rocket surgery. They re-arraged th' panel and some stuff don't work properly now. It would be obvious that some wires lost connection. Just ring out th' harness, an' fix th' bad connections. It's simple, albeit tedious.

 

[bluerooster]

I found a problem with a new harness, worked well on the bench, but now that it's installed, Nav2 audio isn't there. Found that the connection at one of the pins got lost in the install process. Installed new pin, all is well. It's not all that complicated. Just a matter of pin A being connected to pin A at the other end. And it's nice that older avionics wiring is color coded, (all white). Makes it much easier.

 

[Tom-D]

Oh good lord!! It aint rocket surgery. They re-arraged th' panel and some stuff don't work properly now. It would be obvious that some wires lost connection.

And as soon as you try to find the broken connection, ten others break.

 

[midcap]

How much rewiring are you talking about here? All new wiring in the entire airplane or just new wiring for the avionics? All new wiring for a Cub is going to be much cheaper for a Cub compared to a Super Cub, and all new wiring in that Super Cub is going to be far cheaper than something like a high performance single or twin. I'd expect similar in the marine industry, where the price goes up accordingly with the level of complexity.

New wiring seems to be a rarity in the aviation world, even if most planes do need it. The cost is just too high in most cases.

Just the avionics, since they are pretty important

 

[midcap]

And as soon as you try to find the broken connection, ten others break.

I really need to get my hands on a plane and start tearing into it.
I would really like to see how different it is than what I am used to.

I would seriously consider getting my A&P if there wasn't the requirement for apprenticeship.

 

[bluerooster]

And as soon as you try to find the broken connection, ten others break.

Well, stuff happens. But usually it's not trying to find the bad connection that causes the others to break. But the repairing of the connection that was found to be bad.

 

[weirdjim]

Which is why Iove (absolutely LOVE) owners who have some technical/mechanical skills) to work with. I suggest these ideas, they implement them, I inspect them and the world is better for them.

To the person above that said that you rewire the airplane for every change, you didn't understand. You take the old radio harness off the terminal strip connector, you put the new harness ON the connector, and away you go. Takes ... worst case ... a couple of hours.

Jim

 

[hotprops]

op sinista,r, you should not own a aircraft ,you are not in the know about electric or mechanical things .find good people who you trust and respect them. wreanchers are a whole lot different than wire-up guy's a whole different craft . i was lucky and my ia ap was a great wrench but a poor sparky . so we helped each other out. you are asking toooo much . remember you spend $92 a hour for a GM tech to work on your chevy but dont want to spend more on your aircraft!!!!!!!!!!!!!!!!!!!! .you cant afford to own a aircraft in today's world ,, sad but true .stop crying and grow up

 

[yetti]

Can you further explain "no longer working"? Use words like. Does not power up. Comes on but does not do the functions intended.

I feel like tech support asking if the green light on the lower left hand corner of the monitor.

four paragraphs of an emotional post with bunch of emotional responses will not get your avionics working again.

 

[Sinistar]

Can you further explain "no longer working"? Use words like. Does not power up. Comes on but does not do the functions intended.

I feel like tech support asking if the green light on the lower left hand corner of the monitor.

four paragraphs of an emotional post with bunch of emotional responses will not get your avionics working again.

Sorry if it was "emotional" - actually I learned a lot from the other responses (thanks to those who gave their perspective!). Our last plane had no electronics so we've never needed a IA or messed with avionics. And we always did owner assist annuals but it was time for a change (another story). So this was our first experience with a shop vs individual, avionics related work and a case where something else was broken along the way.

I have no problem sharing details. Basically, the NDB and Loran and their corresponding antennae's were removed (neither were functional). The second part of the work was to shift the remaining equipment down to make room for a larger tablet right under the glare shield. The wiring was long enough to do this without altering or re-wiring anything else hence why the A&P probably felt okay doing the work.

After the plane was started and the master radio switch was turned on we immediately noticed the DME was no longer displaying anything. And the intercom was no longer working. We verified the problem with two different headsets and both pilot and co-pilot stations. At this point we are most concerned about the intercom - that is our priority. The intercom is run through a KMA 24H audio control panel. So my first thought was no power to that unit. However, we were able to route both nav/coms to the internal speaker and to our headsets and listen to ATIS on the field. We can key the push to talk on the yoke and it appears to transmit. So clearly the audio control panel has power and the controls must be working.

If I had to guess, there is also a single switch at the top of the entire panel labeled "Pilot Privacy" (or something like that???). We haven't had the plane long and had only tried this once. It seems like it behaved in a similar manner muting the other headsets. Unfortunately I do not have access to the plane (it is locked in their hangar and closed for the weekend) so I can't troubleshoot it more. So I am wondering if that switch was disconnected or is now shorting and basically muting all intercom. Or maybe if is disconnected it purposely fails to muting all intercom? We tried the VOX dial on the KMA 24H and that was not it. We even tried setting all the way to a hot mic (fully clockwise) and still nothing. And we of course tried all the volume controls including on the headsets. The nav/com volume controls work properly. But Nothing doing for the intercom and audio panel volume adjustments.

The mechanic had a recollection that maybe something related to the intercom was routed through the NDB?

That's what I know so far. I had already emailed them w/r to the pilot privacy switch in case it helps them out any.

 

[yetti]

Intercoms have to have a failure mode so the pilot can still talk and listen even if they don't have power. Sounds like the intercom and DME don't have power... or a ground... and are not powering up. Are they on the same circuit? Check that circuit first.

The NDB will have an audio feed to the audio panel so you can verify the station. Did you turn on the NDB?

What kind of intercom?

 

[SkyDog58]

op sinista,r, you should not own a aircraft ,you are not in the know about electric or mechanical things .find good people who you trust and respect them. wreanchers are a whole lot different than wire-up guy's a whole different craft . i was lucky and my ia ap was a great wrench but a poor sparky . so we helped each other out. you are asking toooo much . remember you spend $92 a hour for a GM tech to work on your chevy but dont want to spend more on your aircraft!!!!!!!!!!!!!!!!!!!! .you cant afford to own a aircraft in today's world ,, sad but true .stop crying and grow up

 

[Sinistar]

Unfortunately I do not what type of intercom? I just know that it all seems to be routed through the KMA 24H audio control panel.

I do know the intercom has 4 stations, all work. The headset mic's vox feature is fully controlled from the KMA 24H including a hot mic when the outside knob is turned fully clockwise. The inside knob is the volume for the intercom only. The top row of buttons routes all audio to the cabin speaker (that was working for the Nav/Coms). The lower row routes all audio to the headsets (that seemed to be working).The knob of the right side controls which Nav/Com gets the Yoke push to talk (which seemed to work). The Nav/Com volume knobs seemed to work (louder/quieter on the cabin speaker and headset).

Actually, I wouldn't have even known if the NDB went through the audio panel! We were told it and the Loran were no longer functional so we never even tried them. I guess the NDB going through the audio panel to hear it receiving something makes sense. It would seem odd that removing just one input to the audio panel would prevent the intercom from working but still allow the Nav/Coms to be heard through it.

 

[SCCutler]

Where are you located?

 

[yetti]

https://www.sigtronics.com/_pdf/air_pdf/air_intercom_pdf/SPA-400_KMA24_Inst.pdf

 

[SCCutler]

The KMA 24H is built with integral intercom.

 

[Sinistar]

Where are you located?

We are located in the Twin Cities area. The shop still has our plane and they were going to look it again this morning. I could tell it was bugging him so I definitely trust he will give it another shot. I'll keep everyone posted.

https://www.sigtronics.com/_pdf/air_pdf/air_intercom_pdf/SPA-400_KMA24_Inst.pdf

Thanks for showing me this. I am going to add it to my binder!!! Maybe they are wired the same(??)...however ours is a KMA 24H? Since the intercom is integrated into the 24H, perhaps the SP-400 intercom module shown in this wiring diagram would not be present for us? Also, I expected to see significantly more wiring given all the radios, navs, dme and ndb are also route to this unit somehow?

 

[SCCutler]

You will not have an external intercom on a plane equipped with the KMA24H.

Best world, you could easily troubleshoot the audio panel by swapping-in a known-good unit, but this is where a good avionics shop's expertise comes in.

Suggestion: It sounds to me as if the testing and troubleshooting have been... random. Not an insult, just an observation, and I could be wrong, but you should download the manufacturer's installation and test documentation and verify the settings and how it is supposed to behave.

This may be of some assistance: http://download.mdhelicopters.com/e...00pdf/500pubs/hmi/hmi3/97/970400/97040010.pdf

If the unit is toast, you might look for a PS Engineering PAC24, which is a slide-in replacement. PS Engineering makes superior products.

 

[Sinistar]

You will not have an external intercom on a plane equipped with the KMA24H.

Best world, you could easily troubleshoot the audio panel by swapping-in a known-good unit, but this is where a good avionics shop's expertise comes in.

Suggestion: It sounds to me as if the testing and troubleshooting have been... random. Not an insult, just an observation, and I could be wrong, but you should download the manufacturer's installation and test documentation and verify the settings and how it is supposed to behave.

This may be of some assistance: http://download.mdhelicopters.com/e...00pdf/500pubs/hmi/hmi3/97/970400/97040010.pdf

If the unit is toast, you might look for a PS Engineering PAC24, which is a slide-in replacement. PS Engineering makes superior products.

Thanks for the troubleshooting guide and the recommended replacement suggestions! I was looking at the troubleshooting guide, got a little lost but it would seem the one relevant symptom we are seeing would indicate a problem within the unit. However, before replacing or even removing I want to let the shop have their look and see if something is simply disconnected, etc.

Also, it was interesting to see a full wiring diagram for a fairly full implementation (looks like they use two of these on the helicopter and even more headphone stations).

And I never know that this unit could be slid out. I knew all the others were easily removable from the front but I wasn't sure of the audio panel was something more "fixed".

 

[Sinistar]

I know this is kind of old but I thought I would post a update for anyone interested and/or helped. It took about a month to get it into the Avionics shop. So we just flew w/o the intercom until then.

The problem with the KMA24H was that a small piece of aluminum had shorted out the VOX circuit (and I think he meant inside the chassis). He told me that the our A&P never would have been able to detect this and hence never stood a chance. While there he said he verified all the wiring was good. He even commented on how good of a job the previous tech did when installing the equipment (which was about 15yrs ago). He also indicated that the wiring was indeed long enough for moving things down. It was just a matter of moving it did it. We had thought of pulling the KMA24H to carry into the shop but everything else was working. And we needed our transponder re-certified anyway. To be open about the final cost, it was about $575 total (A&P to move things and then the subsequent avionics repair cost).

In a way a lot of money for a permanent tablet mount. However, this location is proving to be excellent! Takes 2 seconds to install and nothing hanging on the windshield or above the yolk. On occasion the Android's built in GPS loses signal now underneath the glare shield. It never did that when I held it there by hand to evaluate the location change. So, I have a hunch the small delrin block I threaded it too is playing a role here. However, we use a GLO for my daughters iPad (no built in GPS) which has a second copy of the app as a backup. We are finding the GLO to lock in quicker and updates more quickly. It even locks on while in the hangar so no messing with apps or gadgets once its time to fly. It is also a awesome location for night flying....provided you install a night mode app. The Garmin app (on the Android) even using its own night mode is not dim enough. And now that it is cold, we leave two thin pairs of capacitive touch gloves in our gadget case - nice to have until it warms up inside.

Thanks again for all the help and suggestions.