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United States Department of Transportation United States Department of Transportation

AC 20-197 - Turbine Engine and Airframe Sensor Icing Compliance

Document Information

Number
20-197
Title
Turbine Engine and Airframe Sensor Icing Compliance
Status
Active
Date issued
2025-06-18
Office of Primary Responsibility
AIR-625, Interactive Org Chart: Engine & Propulsion Section
Description

This advisory circular (AC) describes an acceptable method for demonstrating compliance with title 14, Code of Federal Regulations (14 CFR) 33.28, 33.68, 33.75,33.89, a nd 33.91, concerning mixed phase, ice crystal icing (ICI), and other icingconditions for engine inlet sensors. This AC may also assist applicants for part 25airplanes in demonstrating compliance with 14 CFR 25.901(c), 25.1093(b), 25.1309, 25.1323, 25.1324, and 25.1325 c oncerning icing conditions and data obtained fromengine inlet sensors on turbine-powered airplanes. This AC addresses temperature probes, combined temperature and pressure probes, and static pressure probes installed in turbine engines. Manufacturers can use this method of compliance to evaluate probe behavior in mixed phase, ICI, and other icing c onditions, and assess the resultingimpact of engine probe performance on engine and airframe systems. Although the main focus of this AC is on engine inlet probes, the methodology can also be applied toevaluate temperature probes, combined pressure and temperature probes, and static pressure probe behavior regardless of installation location.
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