Altimeter failed IFR check

DesertNomad

DesertNomad

Pattern Altitude
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DesertNomad
I took my plane in for the biannual altimeter and transponder IFR check. It had been reading about 40 feet high. It failed because they said at -1000' it was 60 feet off and allowance is 20'. So I need a new altimeter. After the check, it was reading closer. -5 feet at the place they did the check and 20 feet high at home. Could the check have done something to alter what it had been reading?

They said about $1,000 to swap it.

I just wonder if it were tested again if it would pass since it seems to have changed.
 
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My immediate unfiltered response is find a new shop.

The filtered response is to laugh at them and tell them to pull the other leg.
 
Why... because of the price or the failure? There is one other shop close but I won't take it there. The next closest it maybe 100 miles. The cost it the part, and one hour labor.

My original shop on the field can't do it and is closing anyway.
 
DesertNomad said:
Why... because of the price or the failure? There is one other shop close but I won't take it there. The next closest it maybe 100 miles. The cost it the part, and one hour labor.

My original shop on the field can't do it and is closing anyway.
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Both.
 
I am not sure how much choice I have. It's so hard to know what to do in this area where there are so few shops. :(

Aircraft Spruce lists altimeters for $1100.
 
Ask the shop if they cycled it a few times or just declared it bad. Testing endpoints is always a suspect process.
 
DesertNomad said:
I took my plane in for the biannual altimeter and transponder IFR check. It had been reading about 40 feet high. It failed because they said at -1000' it was 60 feet off and allowance is 20'. So I need a new altimeter. After the check, it was reading closer. -5 feet at the place they did the check and 20 feet high at home. Could the check have done something to alter what it had been reading?
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It is possible they adjusted it to see if they could get it to read within tolerance full range.
 
The $1K was just a guess. I'll know more tomorrow and plan to do an exchange.
 
CMongoose said:
I can't speak to the testing process. However, a repair, overhaul or exchange would certainly be cheaper. For example http://www.flyaqi.com/pressure.htm
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This! I got an exchanged Altimeter as my old one was bouncing around a lot. Have not had any problems with the exchange and the price was right and service was prompt.
 
They do fail from time to time. We had ours tested this year by a guy who was interested in teaching, and I can confirm the tests do include the endpoints and the accuracy scale for passing, changes at the endpoints vs the middle.

There's also a vibration test (tap on it after specific pressure changes and see how long it sticks and how far it moves when tapped) and some other stuff.

Ours at it's worst position (28.80?) is only 20' off and tighter across the rest of the range. I figure I'll keep an eye out if I'm flying in any hurricanes. :)

60' is pretty out of whack. If it's doing that consistently it needs help.
 
They just called me. $1200 for a new one but it will take 90 days. $900 for an overhaul (sending mine in) and it will take 3 weeks.

This is nuts.
 
I had the issue and mine turned out to be an air leak in a tube or something. It wasn't the altimeter. It might be worth a second opinion.
 
John221us said:
I had the issue and mine turned out to be an air leak in a tube or something. It wasn't the altimeter. It might be worth a second opinion.
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Sounds like in your case the plane failed a static system check. The op appears to have an altimeter that failed the altimeter check, which usually gets done at the same time. The shops I've dealt with typically remove the altimeter to perform the altimeter check so assuming this happened to the op, it would be fairly easy to distinguish between the two.

Altimeters occasionally go bad. I've had to replace one so far.
 
John221us said:
I had the issue and mine turned out to be an air leak in a tube or something. It wasn't the altimeter. It might be worth a second opinion.
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If the system leaks it won't affect altimeter accuracy measuring the pressure in the system. That's a different item checked during the same inspection. The altimeter accuracy could pass with flying colors and the static system still leak out of limits.
 
bnt83 said:
If the system leaks it won't affect altimeter accuracy measuring the pressure in the system. That's a different item checked during the same inspection. The altimeter accuracy could pass with flying colors and the static system still leak out of limits.
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I am not an expert, for sure, but it was an accuracy issue. Flight Following caught it and then I had it checked out. It wasn't during an inspection.
 
John221us said:
I am not an expert, for sure, but it was an accuracy issue. Flight Following caught it and then I had it checked out. It wasn't during an inspection.
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That sounds like a correspondence problem the blind altitude encoder must read within X+/- of the pilot's altimeter.
 
John221us said:
I am not an expert, for sure, but it was an accuracy issue. Flight Following caught it and then I had it checked out. It wasn't during an inspection.
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That can be either of the altimeter or the blind encoder going bad. If the altimeter is the problem you fly along at the wrong altitude thinking it's right and the encoder is sending the correct altitude to ATC so what you report to them "level 8500" never matches what they see. This is the reason they have to have altitude info. It's cross checking what they're seeing vs what you're seeing. Nifty, eh? It'll also catch the opposite problem. Altimeter good, encoder bad.
 
He said the altimeter was not removed. They hook up the static system and pressurize/vacuum test it. They reported no leaks, but the altimeter reads wrong (by 60' at -1000' MSL)
 
DesertNomad said:
They just called me. $1200 for a new one but it will take 90 days. $900 for an overhaul (sending mine in) and it will take 3 weeks.

This is nuts.
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Maybe do your own calling on the overhaul. If it's over $300 I'd be surprised.
 
Clark1961 said:
Maybe do your own calling on the overhaul. If it's over $300 I'd be surprised.
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I called around and it looks like 3-4 weeks and around $500. I can't really be down that long so am looking at a core exchange on a new one for $1150 minus the core credit.
 
DesertNomad said:
I called around and it looks like 3-4 weeks and around $500. I can't really be down that long so am looking at a core exchange on a new one for $1150 minus the core credit.
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Cheap, fast, good. Pick two.

Rudy lists $315. AQI is usually competitive. AQI usually returns things in a day or two and has stood behind their work when I had a problem.
 
I am definitely envious of all you folks that live in places with good shops. The pickings are certainly slim out here.
 
DesertNomad said:
I called around and it looks like 3-4 weeks and around $500. I can't really be down that long so am looking at a core exchange on a new one for $1150 minus the core credit.
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Try AQI. I haven't used them but have read about lots of happy people that have. And save yourself a few hundred bucks for another repair down the road.
 
We haven't used him (yet?) but I've also heard nothing but good reviews of AQI.
 
If you want to see a really expensive altimeter replacement, quote one for a glider. They have to work without vibration to assist them in moving.
 
DesertNomad said:
I called around and it looks like 3-4 weeks and around $500. I can't really be down that long so am looking at a core exchange on a new one for $1150 minus the core credit.
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Before making any assumptions I'd verify that your altimeter and blind encoder are separate. If the encoder is in the altimeter that might be the difference in price between what the shop is giving you vs. what you're finding in your own search.
 
mondtster said:
Before making any assumptions I'd verify that your altimeter and blind encoder are separate. If the encoder is in the altimeter that might be the difference in price between what the shop is giving you vs. what you're finding in your own search.
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From what he described, the altimeter face reading was off when the system was pressurized for -1000'. The Altimeter is a United 5934PD-3-A130 so the encoder is separate and was reported as working ok.
 
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denverpilot said:
If you want to see a really expensive altimeter replacement, quote one for a glider. They have to work without vibration to assist them in moving.
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The 727 had a little rubber hammer with a solenoid on it that bashed the altimeter gently every few seconds.

Jim
 
weirdjim said:
The 727 had a little rubber hammer with a solenoid on it that bashed the altimeter gently every few seconds.

Jim
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Haha. That's awesome!

Glider pilot buddy has a story of when he was training where he fixated on one altimeter and his CFI used it as a teaching moment ...

"Look outside. Do we seem to be a little low for pattern entry?"

"Yeah, but..."

"Tap the altimeter with your finger."

... Lightbulb goes on ...

"By the way, there's another altimeter on the left there and your computer has a third one... always cross reference all available data..."

They entered the pattern 300' low and landed normally. ;-)

But a rubber hammer is awesome. Hahahaha. Love it.
 
weirdjim said:
That's what they make FedEx overnight for.
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Doesn't help much when a shop won't cooperate on outside parts. I'm hoping this place works out, as I have already given up on door #1 and door #2.

weirdjim said:
The 727 had a little rubber hammer with a solenoid on it that bashed the altimeter gently every few seconds.
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My dad used to fly those and never mentioned that. Neat.
 
Call AQI...you will have an exchange next week if you call tomorrow and for a heck of a lot less than what they are quoting you.
 
I also highly recommend an exchange with AQI or others. Hell, for the price you've been quoted you're not far off from a G3 install. Well, ok, maybe half, but still.
 
DesertNomad said:
Doesn't help much when a shop won't cooperate on outside parts. I'm hoping this place works out, as I have already given up on door #1 and door #2.
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It sounds like from your posts that you're having problems finding reliable shops nearby. However, you need to have a serious conversation with these guys. When you can easily find a 3-4 day (or less) solution to sourcing the parts, being AOG for several weeks because the shop won't cooperate is unacceptable.
 
I second the opinion of using AQI. I just had them O/H my airspeed indicator to like new for $180. Below is the actual gage:

IMG_5438_zps5apzucs8.jpg
 
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