Radio flyer Part 1 — Deciding on a full avionics stack isn’t always an easy task

This is the first in a three-part series describing the problem with the writer’s currrent avionics package, the solution and his experience flying with the new avionics choices he made.


– Editor.

The first airplane I ever flew that was equipped with a “to die for” instrument panel was a brand new, 1970 Cessna Cardinal. The Cessna dealer/flight school where I learned to fly, and who’s aircraft I rented, had just received it and put it on their rental line. It had dual nav/coms, ADF, marker beacons, glide slope, transponder, autopilot, and even a DME. There wasn’t a blank space on the panel anywhere. The decade of the seventies was the beginning of the age of “cool stuff for the panel.” It wasn’t long before the panel “must haves” included Area Nav equipment, which essentially was a box that utilized a DME and VOR to electronically “move” a VOR to any place you wanted it to be. Then you’d fly the VOR direct to that point, even though it was located somewhere else. Cool stuff. Then we saw the advent of the first lightning detection equipment in the form of the Ryan Stormscope. Digital nav/coms began making their way onto the scene, along with the first affordable HSI’s and more reliable and functional autopilots. Then, in the 80s, Loran became the trendy addition to the panel.

As the avionics evolved and the selection of available units increased, there was a need for more panel space. Panels became more and more crowded as pilots wanted “more stuff” in them. I was working for Cessna in the 70s and the Cardinal is just one example of how Cessna responded. In 1976, they changed the panel design on the right side and came up with much more usable space to add new boxes. (Unfortunately, if they were Cessna made boxes, they often weren’t worth much more than the space they filled up.) You can see the difference in two of the accompanying photos. One is the actual brochure panel photo for the ’70 Cardinal. The only thing missing is the DME, which was installed in the glove box on the right side above the transponder. Other than that, it’s exactly like the plane I flew. Note that there was no audio panel then; just speaker/phone selector switches and a transmit selector switch over the altimeter. Those radios were heavy, too. That full panel in my subject 1970 Cardinal, plus DME, took a toll of more than 120 pounds from the useful load.

Another photo shows the brochure ’77 Cardinal. Even with the extra altimeter (the primary one is an encoding altimeter), and an actual audio panel at the top of the center stack, you can see the extra space available for DME and Area Nav, Stormscope, or even a tape deck. My airplane, which is a ’74, has the older style panel and it’s packed slam full. At least the advent of circuit boards to replace tube-style radios helped in reducing the weight penalty for all this gear.

It’s ironic to me, now, as I look at the panel designs of the planes produced over the past 25 years, that as more panel space became available, less was needed. The advent of IFR GPS, and integrated systems and boxes that do multiple functions, has resulted in far less panel space being taken while providing much more capability. For example, take a look at the panel of the new Piper Archer. It seems almost empty, even though typically it has two Garmin 430s, plus indicators, audio panel, transponder, and autopilot. All this stuff can do so much more than all of the older radios that used to suck up every inch of the ample space on the Archer’s panel.

As the price of airplanes drastically increased since the early 80s, and real advances came mostly in new avionics technology, it was no surprise that prospective airplane owners shifted to used planes but equipped them with the latest Gee-Whiz-Wow avionics. Same capability, lower total price. Indeed, general aviation is fortunate to have such a great selection of avionics manufacturers out there, each offering its own multitude of choices for every possible mission we have for our airplanes.

It so happened that I found myself having to review those choices and decide what I believed was right for me, in regard to upgrading the panel of my Cardinal RG. This was not an overnight process. In fact, the decision-making trail began in the fall of 2000. My plane was finally in the condition I wanted: fully refurbished paint, interior and engine. The only avionics work that was done was some clean-up of the panel and reconditioning of the existing radios. I also added a Garmin GPS III pilot to the control wheel.

For the most part, the radios were pretty reliable. I had the Michel MX replacements for the King 170 series radios. Nothing special — digital flip-flop frequencies and that’s it. The rest of my panel included a DME, Loran, ADF, Wx-900 Stormscope, and ICS. Also interesting to me was that I had come “full circle” since the days of flying that 1970 Cardinal. As far as “items” were concerned, only the Stormscope, VFR loran, and control wheel mounted GPS were extra from the equipment list that 1970 Cardinal. The Cessna autopilot is still marginal at best. Certainly, those extra items represent technology not available for the 1970 Cardinal but, as far as being legal for IFR, the equipment list was nearly the same as the 1970 airplane. Sure, the existing radios in my plane were more reliable, and they worked well enough and got me to all my destinations in the nearly 300 hours I had flown the plane thus far. However, for the first time, while I was on an extended, multi-destination business trip with the RG, I found that lack of an IFR approach approved GPS was truly presenting a hindrance to my travels. I still got the job done, but it got me thinking. And I started studying.

Bendix/King, Garmin and Apollo all had viable products. My first thought was to go for a stand-alone GPS, without any extras like coms or navs. It has always been my practice that when spending money on avionics, I go for the most effective “function” gain for the dollar. What I mean by function gain is that it answers the question, “What can I do with the new that I can’t do now?” For example, I have never paid the money for an HSI because it doesn’t allow me to do anything that I can’t already do. It just makes things easier for some people, and that’s great — but not worth it for me.

With the “function” mindset, I initially discounted the idea of GPS/Comm units, or the Garmin 430 (which was setting the industry on it’s ear), and figured that the most new function bang for the least buck was something like a King KLN 89B, or Apollo GX 50. I would gain the function of IFR enroute and approach GPS, and even add a small moving map included within those radios. I had virtually no panel space left, so something would have to go. Easy choice: the ADF would get the death sentence. With some panel rearranging, I could have the GPS in a primary location, and the vacated ADF indicator space would allow me to have a dedicated indicator for the GPS. The cost would be manageable and the resultant value undisputed.

But then some interesting events took place. First, my existing nav/coms started giving me fits. Little stuff, admittedly, but still a dispatch reliability pain with associated repair expenses. Second, my recurrent training activities gave me some great opportunities to fly some of the new stuff on the market, namely the Garmin 530 and 430, as well as the Bendix/King KLN 94 and KMD 550 Multi-Function Display (MFD). I also had the opportunity to do a full in-flight evaluation of the Honeywell (Bendix/King) Enhanced Ground Proximity Warning System (EGWPS) for a helicopter magazine. The system was a pre-certification model in a large, corporate helicopter test platform, and it was awesome. More on the impact of this later.

And thirdly, I had come to the decision that this RG would be a keeper. I’ve owned many planes over the years and my pattern had been to trade every three years or so. Not this time. And this decision is important, when one considers cost amortization and return on investment.

Of all the planes I have owned over the past 27 years, I have never had the pleasure of doing a completely new avionics package installation. Sure, I’d add a Stormscope here, Loran there, that kind of thing, but nothing from scratch, and this might finally be my opportunity to place a full Bendix/King stack in my plane. Anyone who has been flying general aviation for any length of time knows the feeling of flying that full panel of King gear, which has always eluded me in my personal airplanes.

Another thing that eluded me was the ability to fly some of the new UPS Aviation Technologies (UPSAT) Apollo equipment. I started taking some real notice of their impressive magazine ads, and downloaded some material from the Internet, but no one I knew could show me the stuff. The UPSAT literature on the “full stack” system offered some features and functions that nobody else was offering for the same price. Until this Cardinal, every aircraft I have owned since 1987 has had an Apollo loran, all of which were full of features and performed flawlessly. I had to find out more before I made any final decisions.

So, at the beginning of this year, I set out on a self-appointed assignment to learn as much as I could about all that’s being offered for our panels and deciding what’s right for me. The panel would be upgraded, but how and with what? Now that my nav/coms had become an issue, did it make sense to buy a combined unit after all? Only the Garmins offer a GPS/Comm/Nav in one box, so if I didn’t want that unit, how would I work it? If I was going to rip apart my panel, did it make sense to upgrade everything all at once and get it over with, or keep those components that were working well? Which manufacturer would get the sale: Garmin, UPSAT, Bendix/King, or a combination of those or others? It was obvious that this task might not be as easy as I might have thought initially. Next month, the decision is made and its basis explained.

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