AIM ¶ 7-3-4 — Cold Temperature Airports
AIM 7-3-4 explains Cold Temperature Airport procedures: snowflake icons, altitude corrections, and ATC reporting for safe instrument approaches.
In Plain English
Cold Temperature Airports (CTAs) are airports where extremely low temperatures can cause your altimeter to read higher than your actual altitude, putting you at risk of losing Required Obstacle Clearance (ROC) on a published instrument approach.
The FAA has identified specific airports where this is a concern. Here's what you need to know:
- Identification: CTAs are marked with a snowflake icon (❄) and a temperature limit in Celsius on U.S. Government IAP charts in the Terminal Procedures Publication (TPP).
- Current List: Found on the FAA's digital TPP website, listed by ICAO code, airport name, temperature, and affected approach segment(s).
- Airport Criteria: Risk analysis is only performed on airports with at least one runway 2,500 ft or longer. For shorter runways, corrections are optional.
- ATC Reporting: When applying a cold temperature altitude correction on any segment except the final segment, you must advise ATC of the corrected altitude.
- Correction Methods: FAA recommends either the All Segments Method or the Individual Segments Method.
Understanding CTAs is critical for IFR operations in winter — flying the published altitude without correction in extreme cold could put you below obstacle clearance.
AIM Source Text
FAA AIM ¶ 7-3-47-3-4. 7-3-4. Cold Temperature Airports (CTA)
General: The FAA has determined that operating in cold temperatures has placed some 14 CFR part 97 instrument approach procedures in the United States National Airspace System at risk for loss of required obstacle clearance (ROC). An airport that is determined to be at risk will have an ICON and temperature published on the instrument approach procedure (IAP) in the terminal procedures publication (TPP). CTA identification in TPP: A CTA is identified by a “snowflake” icon ( ) and temperature limit, in Celsius, on U.S. Government approach charts. A current list of CTAs is located at: https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dtpp/search/ . Airports are listed by ICAO code, Airport Name, Temperature in Celsius, and affected segment(s). Airport Criteria. The CTA risk analysis is performed on airports that have at least one runway of 2500 ft. Pilots operating into an airport with a runway length less than 2500 ft may make a cold temperature altitude correction in cold temperature conditions, if desired. Comply with operating and reporting procedures for CTAs. ATC Reporting Requirements. Pilots must advise ATC with the corrected altitude when applying an altitude correction on any approach segment with the exception of the final segment. Methods to apply correction: The FAA recommends operators/pilots use either the All Segments Method or the Individual Segments Method when making corrections at CTAs.
Oral Exam Questions a DPE Might Ask
Q1How is a Cold Temperature Airport identified on an instrument approach chart?
Per AIM 7-3-4, a CTA is identified by a snowflake icon (❄) along with a temperature limit in Celsius published on the IAP in the Terminal Procedures Publication (TPP).
Q2When applying a cold temperature altitude correction, what must you report to ATC?
Per AIM 7-3-4, pilots must advise ATC of the corrected altitude when applying a correction on any approach segment except the final segment.
Q3What two methods does the FAA recommend for applying cold temperature corrections at CTAs?
Per AIM 7-3-4, the FAA recommends using either the All Segments Method or the Individual Segments Method when making corrections at Cold Temperature Airports.
Related Paragraphs in AIM Chapter 7