Not long ago I was talking to a pilot friend who said his Garmin GNS 430 couldn’t be repaired because spare parts were no longer available. I was stunned. To me the 430 is still a miracle box, the first complete flight management system (FMS) for personal airplanes. Could this be true?
I checked with the Garmin guys, and yes, some of the earliest GNS 430s can no longer be repaired. The problem is that parts of the original power supplies that were limited to only 28 volts are no longer available. Garmin can still upgrade an old GNS 430 to WAAS status because that involves exchanging a number of parts but can’t fix some of the oldest units in their original form.
The oldest 430s are coming up on their 15th birthday. In consumer electronics that is an eternity. Just look at the number on your iPhone to see how long very successful consumer electronics last before they are superseded.
But in aviation we count in decades, not months or years. The general aviation piston fleet is more than 40 years old on average. The last big airplane production run was between the years 1976 and 1980 so 35 year old airplanes are not only common, they are the norm.
Beech redesigned the instrument panel in the Baron and Bonanza installing dual controls and two-inch engine instruments in 1984. Many of us still call that the “new Bonanza panel.” New as 30 years ago. Of course, when you think original, or early, in a Bonanza you need to go back to 1947.
It’s really pretty easy to find replacement parts to keep our elderly airplanes flying. Spare parts are less available for airplanes that have been out of production for decades, and parts prices are going up a lot for all airplanes, but none of us would think of junking an airplane simply because its 40 years old, and certainly not 15 years old. But we sure wouldn’t plan to drive a 40 year old car every day. Or even expect it start most mornings given the run of way below average temperatures most of the country has had.
The odd thing is that it’s possible to keep many of the avionics built 35 and 40 years ago flying when it won’t be possible to maintain today’s avionics for nearly as long. The autopilot flight director system in my airplane, a Bendix/King KFC 200, dates back to the 1970s when the airplane was built. It still works great, gets fixed every few years, but parts are still available. The King KX 170 navcoms that were originally installed in my airplane are almost certainly flying on in some other airplane after they were replaced by a GNS 430 and 530.Why can older avionics go on when much newer designs become obsolete?
The answer is that electronic components have become integrated and designed for specific functions. In the “old” days when you needed a resistor to make your radio function you soldered it into the circuit. Same for a capacitor, or transistor or whatever. If that component fails today, you solder in another one. These so-called discrete components are still readily available and not expensive.
But over the past 25 years or so electronic components have been integrated into a single device that contains dozens or even hundreds of what were once functions of individual components. These “integrated” chips are reliable and compact, but are not off the shelf components. They are typically designed for use in a specific piece of equipment. They require specialized manufacturing that is only realistically possible in volumes.
Avionics displays are an even bigger issue in obsolescence. Flat screen display technology is so diverse and is advancing so rapidly that by the time an avionics box can be designed, certified and enter the market its display is nearly obsolete in consumer electronics terms.
What the major avionics companies must do is make lifetime buys of unique components and glass displays they use in new avionics because the components will soon be obsolete. In other words, they need to predict how many components will be needed to manufacture new boxes, and then order enough more to become replacement parts, for the entire useful life of the equipment. It’s a big expense and it’s really impossible to know what the “lifetime” of any avionics will be.
None of us would try to nurse along a 20 year old computer, or even a 5 year old phone, but I am used to avionics working well, and being repairable, until I’m tired of them and something much better comes along. Those days are passing by quickly.
I had one of the very first GNS 430s installed in my airplane and still love what it can do, though it is now updated to the WAAS version. The Garmin GTN series with touch screen have superseded the 430/530 in the Garmin lineup, and they are even more capable systems so there is a great solution at hand when the 430/530 can no longer keep flying.
Since the beginning the prudent airplane owner has budgeted for future engine overhaul. With the still accelerating advances in electronics and the short life cycle that brings it looks like we will need to plan and budget for avionics renewal like we do for engine overhaul. Avionics don’t wear out like an engine, but they are now becoming obsolete quicker than ever before.