NTSB Issues Recommendation A-12-021 to FAA Regarding STC Compatibility

The National Transportation Safety Board, identified by reference number ERA10FA140, has issued Recommendation A-12-021 addressed to the Federal Aviation Administration. This directive calls for the development of specific guidance and checklists to assist installers performing supplemental type certificate modifications. The goal is to help determine compatibility between new STCs and any previously installed modifications on an aircraft. This process aims to ensure that new installations do not adversely affect structural strength, performance, or flight characteristics. If the proposed guidance indicates potential adverse effects, additional testing or engineering evaluation must be performed prior to installation.