Stand-By 2.25" Altimeters

I have the UMA 2.25" single-pointer altimeter for stand-by with my GRT system for the sole use of determining altitude if I lose all electrical. My local avionics shop has told me that they wouldn't do an IFR pitot-static cert as all altimeters visible to the pilot must be able to calibrate to appropriate standards. The UMA won't pass. So.... aside from the Winter 2.25 altimeter, is there a small digital altimeter with it's own power source that can be used, or another option? Last resort is to just put a cover over that UMA altimeter, or remove it and plug the lines.

Jim

Mid Continent Instruments make high quality stuff.

http://midcontinentinstruments.com/index.php/products_services/catalogs/

And the prices reflect that.. for list price of $4,465 it better be a good altimeter

I'd put some masking tape over it and go back and get your cert.

How it managed to fall off later is a problem you'll need to take up with 3M....

I'd seen the Mid Contient stuff as well. That's one that's almost impossible to justify unless it's going into a 737 BBJ.

Have you considered the MGL Infinity Single Altimeter:

http://www.mglavionics.com/html/infinity_singles.html


At $250 it is a great deal. If you want it to have an internal power source, it would be pretty easy to wire in a small sealed lead acid battery with a diode for power backup. Sure beats the alternatives.

What FAR requires this?

Jim P said:

My local avionics shop has told me that they wouldn't do an IFR pitot-static cert as all altimeters visible to the pilot must be able to calibrate to appropriate standards.

Click to expand...

I would ask the shop for the source of that requirement. Not sure what your situation is, but going to another shop might be an option.

Ryan

bullojm1 said:

Have you considered the MGL Infinity Single Altimeter:

http://www.mglavionics.com/html/infinity_singles.html


At $250 it is a great deal. If you want it to have an internal power source, it would be pretty easy to wire in a small sealed lead acid battery with a diode for power backup. Sure beats the alternatives.

Click to expand...

This unit should easily fill your needs and it is built to the usual TSO-10b requirements (so it is indeed a good deal). It can be user calibrated as well if there is ever a need for that.
It can play VSI for you as well...

It has very low power consumption and will operate on a small 9V transistor radio battery for many hours if this is required. It is normally just plugged into the 12 or 24V bus.

Rainier
CEO MGL Avionics

We've sorta/kinda has the same issues along the way...

UMA single pointers will sometimes pass, sometimes not.

Winter altimeters are for the most part pretty darned too but cost nearly $1K.

The certified Mid-Continents are really good, but really expensive.

The MGL units we've used and they are also good, but when people are going with backups that are "steam gauges", they usually want an aneroid non-digital instrument to backup their digital EFIS, which is why they aren't as popular (let's please not get into that discussion here). I remain rather ambivalent about that particular issue. We have installed the MGL's and they do work pretty darned well. They can be a little difficult to read in the sun, but as Ranier says they will run on a 9V batt (just remember to replace it once and awhile).

The falcon units sort of fall into the same category as the UMA stuff. Supposedly both UMA and Falcon have been working on 2/3 pointer small altimeters for years, but I've yet to see anything from them just yet. UMA and Falcon single pointers have been the de-facto backups for the large majority of people to date, although as I said we have done some MGL's and some Mid-continents as well.

Not a lot of options I know, but that's where we're at!

Cheers,
Stein

Another business opportunity

This looks like another business opportunity for someone. I'm sure the MGL units are nice, but it would be great as Stein said to have a 2.25" version of the "standard" altimeter. I bought an old 3 hand 2.25" altimeter on eBay, but it does not work. I risked the $99 or so that I paid for it just in case it did.

Someone could easily track down the Chinese factory that makes someone else's altimeter, and get them to make a 2.25" version. They are very accomodating in my experience.

This won't help if you lose all sources of electrical power, but many transponders (the slimline apollo sl70 and garmin 327/330 for example) will report the encoder altitude. If you use a cheap encoder rather than the grt for the transponder, that gives you a second altitude source for $150 or so that is certifiable.

GPS receivers, even hand-held ones, are very good at AGL measurements so you won't hit the ground, but are not so reliable for barometric altitudes.

I did talk to UMA at OSH this year as I'd also understood they were going down the road to produce a 3-pointer 2.25. Unfortunately, the economy intervened and UMA cut the R&D team working on the new altimeter, so the hopes for a UMA model are now nill, thus the search for an alternative.