Ch 22 - Electrical/Avionics - Part 2

Panel choice

Let me just skip to the chase and give it to you straight, then I’ll discuss a few of my reasons.

I chose two GRT Mini-AP, and I'm also switching radio to a Garmin GNS480 GPS/NAV/COM.

This is what the new panel will look like (everything to scale)

Forgive the model, he was a bit excited.

“But wait a minute… didn’t you just install an IFR Garmin GPS/COM radio?”

I can see this might be a little confusing. Allow me to explain…

To tell you the truth I did initially plan my whole panel upgrade behind the GNS300XL, and some sort of small EFIS (Electronic Flight Instrument System). Although not the most intuitive of boxes at first, the 300 works very well, and I have been slowly getting more used to its menu structure, and where to find what I need in flight. However, when my buddy Wade (under my recommendation and a whole lot of his own research) purchased a GNS480 for his Long EZ, I felt both happy for him and jealous at the same time.

The 480 has a real FMC-like menu structure and feel, akin to what I already use everyday at work. The 300 in comparison feels more like a backpacking GPS installed on a plane. Perhaps I’m being a little too harsh.

Anyway, during his radio search Wade developed quite a few contacts, and to his credit he had kept an eye out for me, sending a few good deals my way every so often, even though I kept refusing them. You see, I did not want to pour any more money into this project at the time, but when his last good deal came about, a GNS480 at half price from a trusted source, I just had to say yes first, then figure it out the details later.

As you might have realized by now, Wade is a real gem of a friend, and I am lucky and honored to count him among mine.

The GNS480 came out of an RV7 that was upgraded to newer Avidyne radio.

Garmin GNS480

The deal went down smoothly, and the radio arrived in working order as expected. 

GNS480, tray, backplate, and memory card reader.

That's one good looking box!

Yep, I will have to figure out what each pin does, and what to connect it to.

Fortunately not all pins are used for every installation

The card reader will be used to keep the IFR database current

I also purchased an additional docking station for two reasons… number one, I wanted to check it out immediately upon arrival to make sure all was well… and number two, this is a very capable radio with an incredible amount of features, and there would be no way I’d be able to learn how to use it on the plane while burning expensive 100LL fuel. One really needs to be able to sit in front of this radio at home, and “play” with it over time to become an expert user.

The docking station was a bit expensive, but a definite must have.

As with all great deals, I ran into a snag, as the software version of this older model radio was out of date. This had the potential of being a pretty big deal, since sending anything to Garmin for any reason incurs an entry fee that runs into the multi-hundreds of dollars before they even take a look at it. To make a long story short, after a couple of weeks of research, a bunch of calls all over the US, and a few moments when I thought I had been had, I found a local avionic shop that was able to update the software, and also soldered a new battery to the motherboard for $180, and did it overnight! Amazing.

In case you didn’t know, the 2.4 update to the GNS480 does a number of things, the most important of which is to enable precision GPS approaches. 

Now that is a very BIG deal!

So, what have I gained by switching from the 300 to the 480, you might ask? 

Well, the best I could hope to do with the 300 was to fly "run-of-the-mill" GPS approach, if one existed at the destination airport. The weather minimums for such an approach vary, but at my home airport they get as low as 400’ AGL (Above Ground Level), not bad at all, and a limitation I would have been very happy to live within. However, the GNS480 can pretty much do any kind of approach like ILS, LOC, VOR, normal GPS, and precision GPS. With this box, and depending on what’s available at the chosen airport, the minimums go down to as low as 200’ AGL (100' AGL if some of the runway visual aid are in sight). This is a big improvement, and opens up a ton more options for getting home safely.

For those of you curious about this box, I’ll link two excellent training videos I found online on how to operate the GNS480. Mind you the Garmin GNS480 is a rebranded Apollo CX80 after Garmin bought out Apollo.

Garmin GNS480 Pilot's Guide

GNS480 In Flight

But enough about radios, let’s talk EFIS!

Why did I go with GRT Mini, and why the Mini-AP?

Well, Wade had been talking to me about GRT for quite some time, but I honestly never really liked the look of the platform. Having used a few different EFIS designs over the years on a number of commercial airplanes (B757, B767, B777, A320, CRJ, and BA4100), the GRT graphics always seemed a little... let's just say "home made" to me. 

GRT's Mini-AP in PFD (Primary Flight Display) mode.

I did like the look of Garmin's and Dynon's displays over GRT's, but when I saw Wade's Mini-X in person I was pleased it was actually better than I had anticipated. 

After downloading the GRT manuals and comparing features, I was astounded at what GRT Avionics had been able to pack into their product. Neither Gamin nor Dynon could compete in this small form factor, at this time.

Pretty much if you can name it, GRT can do it… autopilot coupled Synthetic Vision approaches, Highway in the Sky, Obstacle depiction, color coded Terrain, Traffic, Weather, Flight Director, Engine Instruments, Angle of Attack indicator, Height Above Touchdown Zone readout, the list goes on and on. They also do some stuff I couldn’t even name at the time, like Google glasses Head-Up display! 😱

So much information packed in such a small footprint

Your typical "dumb" HSI/DME/RMI/GS indicator 😛

Yep, this course will run you into the side of a hill (highlighted red)! Talk about increased Situational Awareness! 😎

Customer support has been very friendly before and after my purchase, and I worked with salesmen and engineers alike over the span of a few weeks designing my own redundant IFR system based on two Mini-AP.

So, why the AP and not the Mini-X? 

While the X is probably a slightly better deal given its cheaper price, I wanted to be able to run the GRT autopilot servos from either one of my Minis via a Source Select switch for redundancy (in case of one EFIS failure). True, the X could do most of it, if one purchased the optional software, as a matter of fact the Mini-X can almost be turned it into an AP if you add enough cash, but I decided wanted the benefit of full vertical guidance like Indicated Airspeed, Vertical Speed, or Glide Slope capture ability right off the bat, as opposed to just an Altitude Hold mode.

I think this should be enough info to get your gears spinning. Next time I’ll get into more details about my specific panel design.