New FAA rules are simplifying the process of obtaining certification for significant changes to products that are already type certified.

A final rule published this month narrows the scope of the certification requirements to require that only areas affected by changes meet the latest airworthiness standards. This revises regulations adopted in 2000 that requires a certification applicant demonstrates that the entire “changed product” comply with “applicable” airworthiness standards.

The 2000 regulations were necessary because many changes to aircraft and aircraft components were not required to demonstrate compliance with the latest standards and “incremental design approval changes accumulated into significant differences from the original product,” FAA says.

But the agency says it recognizes that the wording “may establish a requirement for a compliance showing that is too broad for an applicant for a major design change.” Areas not affected by a change do not need to be reapproved, the agency says.

“By requiring applicants to show the ‘changed product’’ meets applicable requirements, we inadvertently required the entire product be shown to meet at least the requirements that applied to the original type certificate,” the agency says. “This was not our intent and was neither the FAA’s practice before the adoption of that rule, nor has it been our practice since its adoption.”