"Andrew Gideon" wrote in message online.com...
I'm considering trying to convince my club to switch to the eGryo-3 instead
of a differential pressure vacuum backup. However, I'm curious about a
couple of things.

I presume you're talking about the Precise Flight standby vacuum (or something
like it). Why get rid of it if it is already there?

The differential pressure mechanism is - I believe - STCed. What would we
need to go through for a panel mounted eGyro-3 (assuming it isn't STCed)?
A field approval, requiring an inspection? Complex? Expensive?

Unlikely to be approved for installation if you asked any FAA type. These
things do not meet the requirements for aircraft parts. The STC would be
the least of your worries. The big question would be if such a system would
even require you to mention it to the FAA. I'm not going there, you will get
differing opinions from different people.

Also, the differential pressure mechanism powers the DG. I see that the
eGyro-3 provides AI and TC backup. Does it also provide heading
information?

Presumably the differential pressure system feeds ALL the vacuum instruments
which is typically the DG and the AI. The TC is usually already electric.
The eGyro-3 provides only the AI and TC functions (why no heading info
I do not know)