The FAA recently released a draft version of an advisory circular (AC) that outlines how the industry can comply with the agency's changed products rule. This rule impacts the costs for obtaining aircraft, engine, propeller, and avionics upgrades that require a supplemental type certificate (STC).
The FAA wanted the STCs for all aircraft to meet the certification rules in effect when an application is made (current rule) rather than the standard in place when the aircraft was built, but AOPA successfully argued that there was no measurable safety benefit to requiring this for smaller GA aircraft weighing 6,000 pounds or less. "This exception is significant because most GA aircraft were certificated under rules dating back more than 30 years," explained Andy Cebula, AOPA's senior vice president of government and technical affairs. "Without these changes, future enhancements to small GA aircraft, such as avionics and other safety upgrades, would be in jeopardy because of the cost and complexity of meeting today's certification rules."
The special treatment of smaller aircraft applies except in those instances where the FAA finds that the change is significant—and even then, the burden of proof is on the FAA, not the aircraft owner, to determine that a later standard applies.