GAMA and global standards body ASTM International are in Brussels this week hosting a workshop where it appears that the rewrite of EASA CS-23 and FAA Part 23 aircraft certification rules is taking shape, aiming for proposed rules to be published by both agencies next year. Known as the “CS/Part 23 Reorganization” initiative, the effort drops weight as a measure of performance or complexity.

Rather, four “airworthiness levels” are to be created, from zero to 19 passengers. The idea is that the acceptable risk should decrease as the number of passengers grows. These levels “will be one of the factors, in addition to VFR/IFR, that determine what is necessary for compliance,” GAMA director for European regulatory affairs and engineering Gregory Bowles told AIN.

The reorganization of CS/Part 23 hinges on the breakdown between actual rules and airworthiness design standards. Rules, essentially safety objectives, are being rewritten by EASA and FAA; airworthiness design standards are the technical details–accepted or not by the authority–developed in the ASTM’s framework, directly involving the industry.