Training

October 2019 Issue




Sub-$5K EFIS: Aspen, Garmin

Shopping the entry-level EFIS market for fitting a vintage Cessna shows you'll likely spend more for optional accessories for full compatibility.

The way we see it, the market has never been more competitive when it comes to budget glass and it's driving buyers to avionics shops like nobody's business. And with entry-level EFIS advertised at the $5000 sweet spot thanks to more supportive FAA certification requirements (STC instead of TSO), for many it's finally time to upgrade.

"I've owned my 1962 Cessna Skylane since 1990 and the recent advances in tech, plus the FAA's attitude toward modernizing our fleet, has me moving toward upgrading to a totally electric panel," Chris Erkmann told us while he was planning the EFIS upgrade for his airplane.

Erkmann initially wanted us to backstop his planning to install a couple of Garmin G5 flight displays, but we helped kick the planning up a few notches by digging deeply into a couple of other interfaces he and others might get quotes for. We came up with three options (not in any preferred order) worth fetching proposals for. What works for this 14-volt, round-gauge Cessna could easily work for a bunch of other airplanes, too. First let's look at mixing brands, and older avionics.

Use What You Have

If it's compatible, we say keep it. Erkmann's Skylane has an existing Garmin GNS 430W, so it's already an instrument airplane that flies LPV and ILS approaches. And since the 430W is WAAS, it feeds data to an Appareo Stratus ADS-B transponder, so the airplane is set for the upcoming U.S. mandate. The 430W is backed up by a King KX155, driving a KI209 nav head. The audio panel is a King KMA24-hardly state of the art-but it's bulletproof. The autopilot is a single-axis, turn coordinator-driven S-TEC 40.

Since the primary goal is removing the vacuum system, let's look at sub-$5000 EFIS and requirements.

Garmin G5

31 Erkmann full panel 182TWO

When purchased as a pair, two Garmin G5 flight instruments (attitude indicator and electronic HSI) come with reversionary mode so if the G5 attitude display fails, the secondary G5 that's used for an EHSI reverts to attitude mode.

In the case of this Cessna, the idea is to remove the existing attitude indicator and the directional gyro and replace them with dual G5s. No metal-cutting required-the G5s will fit into the existing instrument cutouts. But because of the placement of the control column, the instruments will still be displaced to the left of the natural scan. Not the greatest.

The Garmin GNS 430W can connect directly to the G5 EHSI for displaying GPS course and VHF nav data, but the analog King KX155 nav cannot. That means the existing KI209 nav indicator needs to stay, making this a completely standalone system.

As for the autopilot interface, the G5 EHSI can connect with the S-TEC for heading and course command, but you have to buy the GAD 29B analog/digital converter unit. The package price for dual G5s, including the converter, is $5324, not counting dealer discounts and not counting installation and removal of the vacuum system. Have your shop quote this accurately, but out the door the project could approach $9000.

Aspen Evolution E5

32 Aspen E5

The model E5 is Aspen's sub-$5000 EFIS and its STC also allows for removing the attitude indicator and the directional gyro. In this Cessna, the E5 slides into the existing AI and DG instrument holes without any cutting. The airspeed indicator, altimeter and turn coordinator (which drives the autopilot) need to stay.

But since the Aspen E5 only accommodates one GPS and one VHF nav input, the King KX155 has to remain as standalone and connected to the KI209 as it is now, and as it would be in a Garmin G5 interface.

Unless you install one, there's really no backup attitude data with this option should the E5 fail. Aspen said it got away with this simply because the unit doesn't have a TSO. We'd back it up with something, if it was our panel-maybe a Dynon D3 Pocket Panel-or a well-placed iPad with portable AHRS. The Appareo Stratus transponder in this airplane connects with the company's Stratus ADS-B In receiver as a semi-portable installation. That's a reasonable option for backup if you practice.

But to connect the autopilot, you need Aspen's optional ($1000) ACU. Add that to the $4995 E5 display- plus install labor-and the bottom-line price could be in the $9000 ballpark. The Aspen requires an RSM (remote sensor module) on top of the aircraft. Like any magnetometer, done right that's a sizable effort.

Ditch That Vacuum System

33 182 Garmin G5

That's precisely what you can do when installing a pair of Garmin G5 instruments, far left in the images above, and Aspen's Evolution E5, pictured in the middle. That's because the STC for each of these systems allows it. The same is true for the G3X Touch and Dynon Certified SkyView. In a small Cessna or Piper, that could mean a significant weight savings when you factor the iron-gyro instruments, the vacuum pump and all of the lines and fittings. The photo to the far right is the plumbing removed from a Cessna 172. But the real advantage-aside from not having to worry about a pump and tumbling gyros-is it frees up space behind the panel. That makes the installation and upkeep easier.

34 Aspen E5 panel shot

Wrap It Up

While you're getting proposals for these two sub-$5000 EFIS options, it's worth having your shop price two others: Garmin's G3X Touch and Dynon's SkyView. Since space is limited in this panel, the only player is the 7-inch portrait G3X Touch installed in place of the mechanical AI and DG. The 7-inch G3X Touch is priced at $7995, but the STC requires that it's connected to a Garmin G5 instrument for backup. Good idea, but that's another $2249. Even with the G3X Touch you'll need the GAD autopilot adapter, plus the KX155 isn't compatible. I wouldn't expect to get out of this installation for under $15,000. But compared to the other options you get SVX synthetic vision, Garmin's wireless Connext interface for tablet play with ForeFlight and Garmin Pilot and an option for displaying engine data.

35 vac shit

There's also Dynon's 7-inch SkyView. With the backup D10A EFIS and major accessories it's $7840, for an installed price that will flirt with roughly $13,000, realistically.

My advice is to bring the airplane to three shops for comparable proposals on all before committing. While you're there, get a demo.