Van's Altimeter problem

I purchased a new Van's altimeter 4 years ago as a back up to my Dynon D-10A for my RV-8 that has yet to fly. It has been installed in my panel for about 3 years and to be honest with focusing on firewall forward, paint, etc., I have not paid much attention to it. I am just about ready for first flight and the altimeter is reading over 15,000 feet.

There is a screw next to the adjustment knob. Can this screw be used to recalibrate the instrument back to zero or is this a bad instrument?

Glenn Vokac
Oswego, IL
RV-8

Yes you can adjust your altimeter. Loosen the screw beside the knob and shift it towards the outside of the case. Pull the knurled knob out and adjust to the proper setting. Then slide the screw back into position and tighten. If the screw comes out use a small pick to move the little shaft in the hole towards the outside of the case then pull the knob and adjust. Be careful not to lose the screw.

15,000 feet? That's quite a bit of adjustment... on the ground... in Illinois. Even 1500 feet off isn't good.

Steve

I'd say it's a bad instrument. Removing the screw and adjusting the barometric scale calibration permits minor adjustments to calibrate the baro scale with the field elevation. No way will it compensate for a 15,000 foot error.

Huge altimeter shift!

I just experienced the same thing as the fellow in this old thread. I too have a Van's altimeter, it is a few years old, and it is a backup to my Dynon. I have yet to fly but over the years, I have played with it and noticed that I could adjust it to about the elevation at my home which is about 200'.

Tonight, I noticed that it's reading over 5000 feet!! I know about the adjustment screw but I'm thinking something went haywire in it and it probably doesn't have enough adjustment. Nobody has touched it except for me over the years.

I'm about to close up the skin over the instrument panel so if I need to pull it, now is the time.

-Does this sound like a a bad altimeter?

-Has anybody experienced the same thing with an altimeter that has been never used?

-Does anybody do repairs on altimeters?

-Is there a recommended brand of altimeter I should consider in case I have to replace it rather than repair it?

Thanks

I spoke with Van's today

So I spoke with Van's today about my Falcon altimeter going belly up after about three years of non-use. Apparently this is not uncommon. There are items that they don't carry because they tend to go bad on the shelf.

They recommended that I send mine to Wultrad, the Falcon vendor which I will do. Of course, I'm well out of warranty.

Here's a tip: don't buy your altimeters too early. See if you can borrow a non operational one to check fit your cut out and to fit check the lines then buy one towards the end of your build.

What goes bad in them? Rubber diaphram?
I have one from Vans also....been sittin' around for a couple of years.
Can't wait to go check to see if its TU also.

He was pretty vague as to what goes wrong with them. He rattled off a list of instruments that can go bad on the shelf though including altimeters.

I've never seen the inside of an altimeter but I imagine that there is a bellows in there perhaps made of rubber. It sure seems to me that USE rather than NON-USE would wear something like that out but I'm no expert.

I think you can tell pretty quickly if yours is bad by taking out the plug and seeing if you can adjust it to field elevation with a reasonable barometric pressure. I crank mine to the max and min pressure settings in the window and I get nowhere close to my 200' elevation.

Mine Too

My Alt. went out from one weekend to the next. Got the 5000 ft error just like you did. I did adjust mine back down and it has been close ever since. I only fly VFR and always double check it against the GPS. I have not had good luck with the Falco instruments.

664781 said:

My Alt. went out from one weekend to the next. Got the 5000 ft error just like you did. I did adjust mine back down and it has been close ever since. I only fly VFR and always double check it against the GPS. I have not had good luck with the Falco instruments.

Click to expand...

I wouldn't have thought that you could adjust that out. I never tried to adjust mine. I called Wultrad Inc, the vendor for Falcon, and they are having me send it in so that they can look at it.

Yea, I think you get what you pay for. I would bet that the $800+ altimeters are much higher quality that these Falcons.

Altimeter update

I sent my Falcon altimeter in to Wultrad, the vendor for Falcon gauges (www.falcongauge.com). They told me that the altimeter sold to me by Van's back in 2007 was manufactured in 2004! The date of manufacture is part of the serial number. It was already three years old by the time I got it. Then, it sat in my panel in my garage for another three years.

The Wultrad rep told me that without use, altimeters regularly go bad. She said that they are shipped in a vacuum bag and as long as it's in the bag, it should be good for a while. Six years though seemed to be too long for mine.

Here's a solution. When you get ready to do your panel, get a hold of Wultrad. They told me that they always have a pile of broken instruments that they will send you for the cost of shipping. It even sounds like they don't even want them back. She told me that some people use them for paperweights. Fit the broken one in your panel then, just before you go to the airport, order a fresh one. Maybe donate the broken one to your local EAA chapter so that the next guy can use it. CHECK THE MANUFACTURE DATE OF THE NEW ONE TO ENSURE YOU DO INDEED HAVE A FRESH INSTRUMENT!

The good news for me is that Wultrad will be shipping me a brand new altimeter for the cost of shipping. I will leave it in the vacuum sealed back until just before I go to the airport this year.

My Falcon altimeter from Vans lasted for about 1 1/2 years. After hearing bad stories about them I decided to replace it with a different make. So, having nothing to lose I pulled it apart and found that part of the mechanism had broken. It was a thin piece of flat copper that is designed to flex and it had fractured to the point of almost completely breaking. I presume it could have been repaired by an aircraft instrument shop but I doubt it would have been worth the cost.

Fin
9A