Digging deeply into the installation data for Garmin’s new GTR200B comm radio got us thinking about the requirement of TSO certification. With autopilots and primary EFIS systems being approved without a TSO, but instead via AML-STC (approved model list supplemental type certificate), are the days of TSO approval coming to an end? Garmin-a company that cranks out a lot of them in short order-says no. You don’t have to dive far into the regulations to see why.
The GTR200B, like most Garmin avionics aimed at the LSA and experimental market, doesn’t have a TSO and it doesn’t have an STC, pretty much killing it for Part 23 certified aircraft. And yes, a retrofit comm radio requires some form of certification. The TSO process remains the most common way to get there. It’s a vigorous and expensive approval process that can drag along.