UAvionix AV-30-C Attitude Indicator field approval & installation

[Learjetter]

I wanted an additional attitude indicator in my '77 NA G-model panel and looked at several options (G5, Gi-275, another vacuum one, Sandia Quattro, etc etc) and determined that since my primary is still vacuum (follow-up for 400A autopilot), I thought an electric one would be a nice backup. And the UAvionics AV-30-C provides Attitude, Airspeed, Altitude, AoA, g-load, OAT, TAS, etc., so I determined it suitable for my needs.

Using Non-Required Equipment Safety Enhancement (NORSEE) policy, I sent an inquiry to my FSDO seeking field approval to install UAvionix AV-30-C (which is STC'd for many aircraft, even as a primary replacement, but, of course, not a Skymaster).

My avionics rep at the FSDO turned out to be a co-conspirator, and agreed to do the field approval after a couple days research and chatting about NORSEE policy and reading the AV-30 install manual.

We negotiated the Form337 block 8 language, and I ordered an AV-30-C from Spruce along with the Davtron C307PS OAT gauge. My local avionics guy built the simple harness, and we installed the gauge in about 4 hours. I put the OAT probe under the right wing near the boom, and we did have to extend the 12' of shielded cable by about 4' to run it all the way to the AV-30-C which I put on the pilot's side just above the Nav 2 course indicator.

Software configuration required a test flight, which went fine, and we entered the appropriate offsets for temp, altitude, airspeed, etc. to get the AV-30-C indications to be consistent with the aircraft's primary gauges.

My friendly local A&P/IA supervised and inspected the work and signed off the Form337.

In case anyone else wants to do something similar, here's the language I used in Block 8 of the Form337 for the AV-30-C installation:

1) Installation of the AV-30-C as pilot-selectable Attitude Indicator or Directional Gyro is supplemental only; it is not intended as a replacement for or modification to an existing, approved, or required system.
2) Installation is Field-Approved per FAA AIR Policy Statement PS-AIR-21.8-1602 "Approval of Non-Required Safety Enhancing Equipment (NORSEE)."
3) Installed AV-30-C (PN UAV-1003429-001 SN xxxxxx) at FS79 in pilot's upper right instrument panel with reference to UAvionix's AV-30-C installation manual UAV-103947-001 Rev D. Unit receives power from existing Avionics bus, and is connected to the aircraft's existing pitot and static tubing. A separate, stand-alone Davtron Outside Air Temperature probe (PN C307PS) is installed under the aircraft's right wing and is connected to the AV-30-C. AV-30-C provides mutable voice annunciations through unused DME audio channel in existing audio panel.
4) In this configuration, any failure mode of the AV-30-C has no effect on the airworthiness or IFR certification of the aircraft, nor does any failure mode of the AV-30C affect the aircraft's existing VFR or IFR flight capability. Pilot's guide (UAV-1004044-001) and AFMS (UAV-1003946-001) added to POH.
W&B data:
B.E.W. 2957 ARM/CG: 141.3 Moment: 417769.8
AV-30-C 1 79.0 79.0
2958 141.28 417848.8 Useful Load: 1672