New avionics!

The redo of the panel avionics is done!

There is much to like here. The new panel is far more functional than the outgoing one.

Transponder – Garmin GTX-345

Kicking off this upgrade is the transponder, as ADS-B is the real reason this whole process started. Sitting where the Bendix/King KT-76C used to be, now lonely out on the right stack, is the GTX-345 ADS-B In and Out transponder. The plane is now fully 2020 compliant. The box also gets all the ADS-B In goodies displayed on the GTN-750. You now have Traffic and Weather available.

Note: you do not need to touch this box, so far away. It is paired up with the GTN-750, so the essential functions are all available from the much closer touchscreen. Though unassuming, this box should greatly increase situational awareness in the cockpit.

GPS Navigator – Garmin GTN-750

The star of the show is what replaced the Bendix/King KLN 94, KMD 550, and one of the KX 155A. The big and clear screen of the GTN-750 now dominates the center stack. There is no better GPS/NAV/COM on the market today.

As this is a WAAS receiver, the plane now has the capability of doing LPV approaches, something the KLN 94 could not. The GTX 345 feeds it ADS-B info to display and you can control the transponder with touchscreen controls on the GTN-750. Though the G5, it can now direct the autopilot with GPSS. Also, the CDI for this box is the G5.

NAV/COM Radio – Bendix/King KX 155A

This is a holdover from the previous panel. The old COM1 is now COM2. With a previously upgraded LED display to replace the failing EL display, this now means the plane has two glideslope receivers. The CDI for this box is still in upper location, as the GTN-750 uses the G5 for the CDI. This radio is still one of the best on the market and is actually a bit better than the one in the Garmin box.

Attitude Indicator – Garmin G5 AI

Commanding your attention in the middle of the six-pack is a Garmin G5 AI to replace the previous vacuum instrument. More than an AI, it includes airspeed, altimeter, VSI,  heading, and other functions. Though only primary for the AI, it renders the other round dials next to it redundant. This device is backed up with a battery, so that it will continue to run for nearly as long as a full tank of fuel.

Horizontal Situation Indicator – Garmin G5 HSI

Paired with the G5 AI above it, the G5 HSI introduces much new functionality. Replacing the previous vacuum DG, this is now a fully functional HSI being driven by the GTN-750. Also battery backed, it can be put into reversion mode to become an AI should the primary AI above it fail. Another bonus is that this box now runs GPSS! Turn on GPSS on the HSI and put the KAP-140 into HDG mode, and you now have perfect GPSS complete with turn anticipation. Watch the plane fly holds and approaches for you nearly hands off.

USB Ports – EI USB-6A

I got tired of noisy and inconvenient car chargers. On the left and right of this device are 2.1A of USB power. The top and the middle provide 1A. Your stuff stays charged, that simple.

Vacuum System – GONE

Yep. No more vacuum instruments. Goodbye vacuum issues. The only thing remaining from the old vacuum system is the inop gauge, and only because it’s shared with amp gauge.


This was a pricey upgrade, running about $36,000. Parts cost was roughly:

  • Garmin GTN-750: $14,800
  • Garmin GTX-345: $4,500
  • Garmin G5 AI: $2,100
  • Garmin G5 HSI: $2,800
  • EI USB-6A: $190
  • Vacuum removal: $150
  • Breaker panel: $240
  • Wiring: $160
  • Static system: $120

Pacific Coast Avionics charged 125 hours of labor to install all of this at $85/hour for a total of $10,600. It took four calendar weeks.

I’m raising the cost of a Hobbs hour to $164. I think this is quite fair, as the function is much increased, but is still a significant savings over the G1000 Skyhawks.


New avionics!