So you’re ready to take the plunge and install equipment that meets FAR 91.225 and 91.227 requiring ADS-B “out” for flight in regulated airspace after the end of 2019. Can you do that? Is there a certified option available for your airplane? Maybe. But maybe not.
If you built your own airplane, or bought an E-AB that someone else built, the answer is no. If you own an LSA the answer is also almost certainly no. And if you own a pretty new standard production airplane with a factory installed flat glass avionics system the answer is also probably no.
Sounds crazy, doesn’t it? The FAA and the avionics industry are urging all airplane owners to act now and get certified ADS-B equipment installed and approved because there won’t be enough radio shop capacity to handle the crush of installs at the last moment.
But the FAA has tied itself into such regulator knots that many airplane owners simply don’t have a certified path to ADS-B compliance.
When the FAA was finalizing the ADS-B rules more than six years ago it was, and remains, extremely concerned that all approved equipment meet a very high standard for precision and reliability. After all, when we make it to an all-ADS-B world an airplane will be invisible if its system doesn’t function. Worse yet, if an ADS-B broadcasts inaccurate position, altitude, velocity and so on it could create a collision threat rather than resolve it.
So the FAA made the ADS-B certification rules extremely strict. For example, initially every specific piece of equipment must be approved in each type of airplane. There would be no multi-model (AML) STCs granted. That idea lasted for a couple years until it became unworkable so now there are AMLs covering installation of specific ADS-B equipment in hundreds of standard category airplanes. But so far the FAA is clinging to its individual model approval for helicopters.
Under its number one priority to keep ADS-B rules strict the FAA apparently forgot about homebuilts and other experimental airplanes. The rules require an STC (supplemental TYPE certificate) or TC (TYPE certificate). I capitalized type because that’s what is missing in an experimental. By its very existence an experimental aircraft has no type certificate. It’s a one-off, no matter if homebuilt, prototype, exhibition or developmental.
Maybe ADS-B in a homebuilt could be certified by an FAA field approval where an FAA office approves modification of a specific airplane. But that doesn’t seem to work for homebuilts. It is the builder who is the “approved” modifier and equipment installer. A field approval normally is granted to an individual based on work performed on other airplanes of the same type. There’s that word again.
Some builders are installing ADS-B equipment that is potentially certifiable and believe they have met the rule. But they haven’t. The rule requires flight manual supplements, operating restrictions, a performance test and other approved paperwork and there is no way for a builder to get there.
Under the ASTM rules that govern factory built LSA only the manufacturer can approve any change in the airplane, including installation of avionics. So there can be no STC for an LSA because there is no FAA type certificate for the airplane. No radio shop can ask for a field approval because only the manufacturer, not the FAA, can approve any change. How will this be resolved for LSA owners who want and need ADS-B capability? The situation is particularly worrisome for owners of LSA whose manufacture has exited the business. Who will spend the money to get an ASTM approval for those airplanes and how would the process work?
And the airplane left out of a path to ADS-B so far that is most surprising is a newer airplane with glass cockpit. When a complete avionics system is installed by the airframe manufacturer it is usually part of the type certificate, just like the ailerons or wing structure. The only way to add ADS-B capability to such systems is for the manufacturer to amend the TC, which can be cumbersome, and expensive and so far none have complied that I know of.
In some other airplanes a manufacturer delivers a new airplane with a complete integrated avionics system under an STC. But the complication there is that the airframe manufacturer may own the STC, or almost certainly controls the STC. That means that even though the maker of the avionics has ADS-B equipment designed and ready for certification it can’t get approval on its own because it doesn’t control the STC.
I’m sure there are other situations that I’m not thinking of where an airplane owner ready to invest in ADS-B out equipment simply has no path to certification. And changing FAA regulations never happens quickly so I don’t know how these conundrums will be resolved.
If you have a homebuilt or LSA what can you do? The only sensible answer is to wait on the FAA. If you buy and install equipment that you think can be approved in the future you may guess wrong. If you have an airplane delivered from the factory with a fully integrated avionics system you’re stuck waiting, too. So the mixed message from the FAA is the standard hurry up and wait.