Airworthiness Directives, Designees & the PMA Crisis: A Candid Look at GA Regulation with Jimmy Tubbs

In this return appearance on Aviation Masters, Mike Busch sits down again with legendary aeronautical engineer Jimmy Tubbs for a deep, technically rich conversation about the regulatory machinery that shapes general aviation.

From the flawed criteria behind Airworthiness Directives to the erosion of Designated Engineering Representatives, and from PMA approval delays to the disappearance of the Small Airplane Directorate's collaborative processes, Jimmy pulls back the curtain on how the system is supposed to work, where it breaks down, and what it costs aircraft owners and the GA community.

This is a candid, experience-driven conversation with one of the most knowledgeable engineers in piston aviation — essential listening for anyone who owns, operates, or maintains a GA aircraft.

⏱ Chapters

00:00 – Introduction & Jimmy's Background

03:00 – What Is an Airworthiness Directive & How Are They Triggered?

07:00 – The Two-Variable Framework: Frequency vs. Severity of Failure

11:00 – Why AD Analysis in GA Lacks Formal Criteria

17:00 – FAA Reorganization: The Loss of Directorates & Senior Engineers

21:00 – The ECI Cylinder AD: Head-to-Barrel Separations & Overreach

28:00 – Corrective Actions That Ignore Supply Chain Reality

31:00 – Short-Wing Piper Rudder AD & the Vintage Aircraft Association Fight