A multi-agency effort to harmonize guidance on determining certification requirements for changed products—known as the Changed Product Rule (CPR)—has reached the draft stage, and regulators from Europe, the U.S., Canada and Brazil are urging stakeholders to weigh in.
The guidance material (GM), “Establishing the Certification Basis of Changed Aeronautical Products,” has been released as a draft FAA advisory circular. But it reflects input from the FAA as well the European Aviation Safety Agency (EASA), Transport Canada and Brazil’s Agencia Nacional de Aviacao Civil (ANAC).
“Updating and harmonizing the current GM on the Changed Product Rule (CPR), Transport Canada (TCCA), the FAA and EASA have been collaborating since 2003 with the aim of harmonizing the implementation of CPR by agreeing to publish harmonized interpretations of CPR regulations, policies, procedures, and guidance through ACs or GM and staff instructions,” EASA explains in a notice. ANAC jointed the effort “recently,” EASA adds.
The guidance is meant to help organizations determine the certification basis for an amended type certificate, supplemental type certificate (STC) or amended STC, “detailing the requirements (evaluations, classifications, and decisions) to be made throughout the process,” the FAA’s draft document explains. “The certification basis can vary, depending on the magnitude and scope of the change. The steps [in the GM] present a streamlined approach for making this determination.”
The 144-page draft guidance includes appendices with examples of changes that are “significant”—meaning the latest requirements must be met, regardless of the product’s original certification basis—and “not significant.” Each example is judged on three criteria: whether it requires a change to the product’s general configuration; if there is a change in the principles of construction; or whether the principles of certification have been invalidated. If any of the three criteria generate a “yes” answer, the change is considered “significant,” and requirements are triggered.
For instance, installing winglets changes both the general configuration and certification assumptions, making them a significant change. But new cabin interiors and swapping steel brakes out for carbon brakes are not significant changes, though the former may require special steps if unusual elements are introduced, and the latter requires recertification.
To comment on the proposed guidance, see faa.gov/aircraft/draft_docs/ac/. The deadline for comments is July 6.