EFIS technology remains the hot topic on the minds of pilots who are upgrading their panels. Any pilot that spends any time in the clouds cannot ignore the possibility of a vacu­um pump or vacuum/attitude indicator (AI) failure in weather. VFR pilots don’t share this concern. If you are concerned about your attitude in VFR, you look out the windshield and correct. The attitude indicator, in most cases, in VFR, is not contributing much to the safety of the flight. That does not mean that a VFR pilot should not understand the role of the AI, in fact I recom­mend every VFR pilot practice flying “under the hood.”

One Christmas I took my VFR Cherokee 140 along with my wife and brother and we flew to Nantucket for the annual “Christmas Stroll”. This is a weekend when shops and vendors decorate storefronts and sidewalks in the spirit of the season, and it draws folks from all around. This combined with the charm of Nantucket’s cobblestone streets and often a bit of fog makes for a delightful atmosphere. When it was time to depart, it was dark and visibility was okay for a VFR departure. I was cleared to depart to the south. Once I was clear of the runway, I found myself over water, in the pitch dark with absolutely no visual attitude reference. My passengers were yapping away, and I asked them to shut and let me fly. I requested a turn-back towards the land as soon as possible which took longer than I hoped. It scared me and caused me to put more emphasis on being able to fly the aircraft in this scenario.

A year later I upgraded to a Cherokee Six and was required to fly ten hours with an instructor. After two hours, the instructor was comfortable that I could handle the Six and asked what I wanted to do. I spent the next eight hours under the hood. Since the AI plays such a small role in VFR flight, VFR pilots aren’t lining up to upgrade their panels with EFIS technology.

The majority of my consultant clients come to me with out­dated avionics looking to upgrade the panel for Light IFR. Most have personal minimums in the 800 to 1,000 ft AGL range. They are comfortable spending some time in the clouds but would rather be above and their destination is usually towards bet­ter weather. Approaches to minimums … “forget about it!” My philosophy is that a Light IFR pilot does not need EFIS in the panel. You can overhaul your gyros and vacuum pump for about $2,500 and have a vacuum system that you should be able to trust (with good filter maintenance) for many hours. For those pilots going light, with a long-term plan for the aircraft, who have already checked off all the important boxes, and with the desire to add EFIS (and have the dough), the discussion is elec­tronic flight instruments, not big screen EFIS.

Let’s look at what is available today in the electronic flight in­strument marketplace. Next month, we will do the same and visit big screen EFIS options. Note that Dynon actually had the first certified solid-state electronic flight instrument in their D-10A. Its role was primarily as the STC backup for their Big Screen HDX EFIS option but was also approved as the first legal replace­ment for your vacuum AI in your certified aircraft. The new D30 (replacement for the D-10A) is only approved as a back-up for the HDX and is no longer an option to replace your AI.

Garmin EFI Options

Garmin came to the EFI market in March of 2017 with the G5 AI and HSI. I noted at the time, that the certified G5 AI just happened to be $50 less than the Dynon D-10A which I pointed out was an example of the benefits of competition. I think the G5 would have cost more if the D-10A did not exist.

Garmin G5/AI The G5 electronic flight in­strument can replace your vacuum/mechani­cal AI in aircraft that do not use the AI as a sensor for their legacy autopi­lots, as is found in many early Pipers and Cessnas. It provides primary at­titude, but also supports the display of airspeed, altitude, vertical speed, slip/skid, turn rate, con­figurable V-speed refer­ences, barometric setting and selected altitude.

The G5/AI version can be purchased over the counter at about $2,725. Garmin’s GTP59 OAT Probe Kit (an out­side mounted tempera­ture probe) is available as an optional module for $525.

Garmin G5 HSI. An HSI’s role is to reduce pilot load by com­bining the DG with the CDI into a single instrument. The G5 HSI interfaces to digital (only) nav sources and to the Garmin GFC 500 autopilot (only) using the GAD 29D interface and the GMU 11 remote magnetometer. Garmin offers this package at $3,715 and can be purchased from your favorite online vendor.

The G5’s configuration doesn’t seem to work for everyone and it has limitations. It requires a careful cut on those plastic over­lays and doesn’t fit as well into an existing panel as some would like. The GI 275 came along in 2020.

The rest of this article can be seen only by paid members who are logged in.
Have a website login already? Log in and start reading now.
Never created a website login before? Find your Customer Number (it’s on your mailing label) and register here.
Still have questions? Contact us here.