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An interesting backup instrument

http://www.flysam.com/features/

What I wonder is what paperwork the installation involves.

I know that EFIS products need an STC (in the FAA world). But this probably isn't "EFIS" because the AI is not on the same screen as the speed and altitude tapes.

Administrator
Shoreham EGKA, United Kingdom

A weird format and layout. All that just to not have to get STCs?

I'm not sure it's that great. While it is supposedly as good as the primary EFIS, being hooked up to the pitot static system, it also suffers from the same single point of failure: the pitot static system. That can easily get clogged up in malicious ways -- I've had it happen with one of my static ports on one side of the airplane causing the altimeter to dramatically over read in a strong crosswind situation. Recipe for disaster.

I'd be more comfortable with a GPS based backup such as the Dynon D1.

Also I don't believe in demand for such an instrument. New planes come with G1000 etc. and a backup instrument (where an STC does not matter) and retrofits can always retain a few steam gauges which are perfect backups. If I were to make an all glass retrofit (why?), I'd certainly not go for this awkward two screen "EFIS".

To be a real backup instrument, it should have its own pitot/static circuitry, indeed, but that is not impossible...

For my non-certified plane it would make a nice primary instrument, but I find the cost excessive.

EBZH Kiewit, Belgium

The paperwork for a second set of static and pitot would be interesting... As would the 10-20A drawn by the pitot heater. Might force an alternator upgrade.

Administrator
Shoreham EGKA, United Kingdom

It would probably require a STC or field approval. It specifies that it complies with TSO C113A. The FAA made RCAllen add the TSO C113 approval to their RCA2600 series and demand a STC or field approval, see http://www.kellymfg.com/images/RCA2600%20information.pdf . Interestingly, the early units don't carry the TSO C113 and only carry the TSO C4c, so don't fall under the requirement. I have one of the early units installed as a backup unit and is installed as a minor mod. It replaced a prior electric TSO C4c mechanical unit that was used as a backup.

KUZA, United States

I've been thinking of this one as a stand by horizon.

Dynon D1

I've seen it in use, the attitude info is valuable and very straightforward. For IFR/VFR night it certainly beats flying partial panel!

What it will do is give you a valid attitude information in case your vaccum or electrical system fails, for a good 4 hours without power.

Plus it will give you gps altitude and Ground Speed. GPS Alt is clearly better than nothing, GPS speed next to unusable but still better than nothing.

LSZH(work) LSZF (GA base), Switzerland

Would it be worth rigging up a backup static source to the cabin? You'd still depend on the single pitot, I guess.

Backup static, to be accurate, would almost certainly need a second pair of static ports, so that yaw does not affect the altitude.

"Proper" planes have at least two sets of static ports, feeding (AIUI) the LHS and RHS instruments. Not that it did this one any good...

Administrator
Shoreham EGKA, United Kingdom

GPS Alt is clearly better than nothing

Is GPS altitude not more accurate than barometric altitude? I'm guessing radalt is the most accurate measure of height but I thought GPS was the most accurate measure of altitude. I've been wrong before though.

Fairoaks, United Kingdom

Backup static, to be accurate, would almost certainly need a second pair of static ports, so that yaw does not affect the altitude.

Alternate static (cabin pressure in a non pressurized airplane) is sufficiently accurate for our means and a certification requirement AFAIK.

Is GPS altitude not more accurate than barometric altitude?

Yes, absolutely. Ever since I had that very dangerous clogged static port encounter, I have put GPS alt on the main screen of my GPS and keep an eye on it. It is very accurate.

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