AC 23-21, ADVISORY CIRCULAR, AIRWORTHINESS COMPLIANCE CHECKLISTS USED TO SUBSTANTIATE MAJOR ALTERATIONS FOR SMALL AIRPLANES (30 SEP 2004)

AC 23-21, ADVISORY CIRCULAR, AIRWORTHINESS COMPLIANCE CHECKLISTS USED TO SUBSTANTIATE MAJOR ALTERATIONS FOR SMALL AIRPLANES (30 SEP 2004)., This advisory circular (AC) provides guidance material for the creation and use of airworthiness compliance checklists that aid in substantiating requirements when performing major alterations to small airplanes. These checklists may be used by Airframe and Powerplant (A&P) mechanics and those holding Inspection Authorization (IA) privileges and by persons performing alterations (modifiers), under the privileges of an FAA Certificated Repair Station (CRS) operating under Title 14 Code of Federal Regulations (CFR) part 145 as well as by Federal Aviation Administration (FAA) Airworthiness Aviation Safety Inspectors (ASIs) to assist in determining that such alterations meet compliance with the Federal Aviation Regulations. These checklists will help identify all the data requirements and outline the data approval methods for a particular major alteration, as well as identify documentation required to further substantiate approval for returning the product to service.