Advisory Circular 23.1309-1D System Safety Analysis and Assessment for Part 23 Airplanes. This advisory circular (AC) sets forth an acceptable means of showing compliance with Title 14 of the Code of Federal Regulations (14 CFR) ยง 23.1309(a) and (b) (Amendment 23-49) for equipment, systems, and installations in 14 CFR part 23 airplanes
