AIN Blog: The End of Avionics Certification for Light GA Airplanes?

 - April 26, 2016, 10:07 PM
Dynon's D10A primary attitude display has been STC'd for installation in some simple Cessna and Piper piston aircraft.

The recent announcement that the FAA has approved a supplemental type certificate (STC) for installation of non-TSO’d avionics in basic single-engine airplanes is a significant development, and I expect this is going to be a hot topic at this week’s Aircraft Electronics Association International Convention & Trade Show, which opened today in Orlando, Fla.

To recap, the Experimental Aircraft Association (EAA) announced on April 6 that it developed an STC for installation of the Dynon EFIS-D10A electronic primary attitude indicator as a replacement for the attitude indicator on the Cessna 150, 152 and 172 and Piper PA-28 and PA-38 (Tomahawk). Flight-testing was accomplished in a Cessna 172M (a mid-1970s model). If the aircraft is already IFR certified, it remains so qualified after installation of the D10A.

The D10A retails for $2,200 and it fits into a standard 3.125-inch panel hole and offers a four-inch-diagonal color display, driven by its own internal AHRS. The STC is for replacement of the airplane’s existing attitude indicator, usually vacuum-driven, but the D10A has many other features that could add much more than the greater reliability of electronics than vacuum-driven mechanical gyros. For example, options include angle-of-attack; autopilot; OAT probe; altitude encoder; serial interface for uploading checklists and software updates; a Dynon bus for sharing displays with other instruments; and expansion modules that connect via the bus. Whether or not these Cessna or Piper owners would be able to install these added features is not clear, but what is clear is that the STC permits installation of the D10A without what is normally required: compliance with an applicable technical standard order (TSO) or parts manufacturer approval. According to the EAA, “Dynon’s product is also verified against the recently developed ASTM 3153-15, Standard Specification for Verification of Avionics Systems. The Dynon unit was flight-tested in Oshkosh earlier this year in the EAA’s own Cessna 172M, with FAA observation.”

For avionics manufacturers, the big question is whether this STC opens the door to further FAA approval of installation of non-TSO’d avionics in certified (non-experimental aircraft) and if so, what that means for the market for their TSO’d products. If the FAA eventually allows, say, the owner of a Beech Bonanza to install a D10A, what happens to the market for certified electronics? 

But there’s a bigger question associated with this significant change. A huge problem with certified avionics is the extensive testing required to meet the applicable TSO standards, plus all the documentation that the FAA requires, not to mention the time FAA engineers have to spend evaluating all the paperwork. What this means in the real world is that avionics development takes a long time and often lags technological capability, sometimes significantly. Chips such as Intel’s Pentium series, for example, had a long life in certified avionics way after consumers ditched them in personal computers. The makers of non-TSO’d avionics, however (and some of them are, like Garmin, players in both the certified and non-TSO’d markets), can take advantage of the latest technology and bring it to market far more quickly. If the owner of an airplane that qualifies for installation of non-TSO’d avionics sees an advantage in technology and price with the new non-TSO’d products, will this hurt sales of TSO’d products?

The manufacturers of TSO’d avionics have invested an enormous amount of money in certification processes, and I’m well aware that the testing that is done is comprehensive and sophisticated. There is a standard that Dynon had to meet for the D10A STC, and that is ASTM 3153-15. Obviously the FAA was satisfied that the needs of safety were met in this case. Will this lead to other approvals such as, for example, our prototypical Bonanza owner being able to install a Garmin G3X primary and multifunction flight display? Does Garmin even want to pursue that market?

There are some who believe that the availability of lower-cost, high-quality avionics for certified older airplanes is all that is needed to resuscitate the general aviation industry. The same people probably believe that elimination of the third-class medical exam would have the same effect. While both changes may offer benefits, they aren’t silver bullets, but it will certainly be interesting to see the effect they have on a shrinking general aviation industry.


The FAA realise that most people flying GA are doing it with an iPad, so why hold back the avionics with stupid restrictions. Not going to hurt iPad market or the TSO market.

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