- Turbojet, Turboprop, Turboshaft, and Turbofan Engine Induction System Icing and Ice Ingestion
- Date issued
- Office of Primary Responsibility
This advisory circular (AC) provides guidance for demonstrating compliance with the engine induction system icing and engine installation ice requirements of Title 14 Code of Federal Regulations (14 CFR) parts 23, 25, 27, 29, and 33. This AC discusses the icing environments depicted in appendices C and O of part 25, appendix C of part 29, and appendix D of part 33. This AC discusses turboshaft engine installations, but not the rotary wing aircraft they are installed on.
- AC 20-147A (PDF)