Before revision: AC 25.1309–1 is an FAA Advisory Circular (AC) (Subject: System Design and Analysis) that describes acceptable means for showing compliance with the airworthiness requirements of § 25.1309 of the Federal Aviation Regulations.
After revision: AC 25.1309–1 is an FAA Advisory Circular (AC) (Subject: System Design and Analysis) that identifies acceptable means for showing compliance with the airworthiness requirements of § 25.1309 of the Federal Aviation Regulations.