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Single pointer altimeter

On most aircraft one can usually choose the model of the 2nd altimeter (on the RHS) and I wonder what people think of these

It seems much less prone to the rather easy 1000ft misread.

There are many of these models, with some at eye watering prices like the Honeywell AM250 (RVSM, ARINC429 pressure altitude output which is actually quite handy) but they all seem to require power in order to work at all.

Administrator
Shoreham EGKA, United Kingdom

Glass cockpit!

... and I wonder what people think of these

My favorite type (after speed tape with trend vector). Have flown for years with one like that in the C421. But as you write, it requires electrical power, therefore I would rather use it as primary instrument and not as backup.

EDDS - Stuttgart

I had one similar to this and I liked it. Unfortunately, it had to go due to it having too much friction and being beyond economical servicing. Every one else hated it though 8-)

LSZK, Switzerland

I'd love one of these, but with a millibar window and 12V. You find loads of the old ones from RVSM conversions.

If you go for a non-encoding altimeter, you need only power for lighting. Ultra-FEI local copy

United Kingdom

That's a nice one but 2 ATI i.e. the small size.

If you go for a non-encoding altimeter, you need only power for lighting

I don't think that is universally true but clearly you found at least the one example.

Administrator
Shoreham EGKA, United Kingdom

What are the options for installing one of these?

Fairly obviously the main altimeter may be used for the autopilot reference so you are screwed into using the KEA130A specified in the KFC225 STC IM. You would need some sort of Major mod process to change the altimeter.

But on the RHS, it should be installable freely provided it is a TSOd item. On an N-reg, you can put almost anything TSOd on the RHS, so long as there is no autopilot connection, and it isn’t an EFIS product. EASA… I don’t know.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

What are the options for installing one of these?

You certainly don’t want RVSM version. They are electric some times for altitude encoder, and sometimes altitude encoder and vibrator. The vibrator is normally not necessary on piston aircraft.

Peter wrote:

Fairly obviously the main altimeter may be used for the autopilot reference so you are screwed into using the KEA130A specified in the KFC225 STC IM. You would need some sort of Major mod process to change the altimeter.

Why? I did changes these on EASA aircraft, again, this was possible as minor change.

JP-Avionics
EHMZ

A minor change if the autopilot STC specifies the altimeter type?

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

A minor change if the autopilot STC specifies the altimeter type?

Yes, sure you need the same output, but that’s it. I don’t know if this would be minor under FAA, under EASA it is.

A minor change is a minor change, it doesn’t matter if this is a minor change to the TC or to an STC. Again, I fail to see how this would be a major change?

JP-Avionics
EHMZ
12 Posts
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