On Fri, 31 Dec 2004 07:36:16 -0400, "Juan Jimenez"
wrote:


"M" wrote in message
ups.com...
I'm considering adding a second (backup) electric AI. The primary AI
is vacuum driven so is the DG.

Two questions: 1. Does adding a backup electric AI require an 337?

Not necessarily. A repair station may be able to perform the work based on a
work order approval, since it's not really a major alteration. Ask your
local avionics shop.

Any work that alters (that includes drilling, cutting, riveting),
needs a 337.

2. Does the electric AI needs to be TSO'ed?

No, but I don't know of any worth their salt that aren't. With what
you need to spend on them you would think they would give you your own
personal engineer!
That I don't know, but aren't you adding this to improve safety of your
aircraft? From my point of view, that should make the answer obvious.

Juan