New Information To Be Included In Instrument Procedures Beginning In March

The FAA plans to implement the cold temperature altitude corrections at “Cold Temperature Restricted Airports” found in Notice to Airmen Publication (NTAP) later this year.

In an Information For Operators (InFO) notice posted on the FAA website, the agency said in response to recognized safety concerns over cold weather altimetry errors, the FAA completed a risk analysis to determine if current Title 14 of the Code of Federal Regulations (14 CFR) Part 97 instrument approach procedures in the United States National Airspace System (NAS) are at risk during cold temperature operations. The study used the coldest recorded temperature for the airport in the last five years and specifically investigated if there was a probability that expected altitude errors in a barometric altimetry system, during these non-standard day operations, could exceed the Required Obstacle Clearance (ROC) used on procedure segment altitudes.

As a result of the analysis, Cold Temperature Restricted Airports have been designated in the NAS. The list of airports, the segment(s) of the approach requiring cold temperature altitude correction and associated operating procedures may be found at www.faa.gov/air_traffic/publications/notices NTAP, Part 4. Graphic Notices, Section 1. General - Cold Temperature Restricted Airports.

The list of affected airports is also available as a PDF on the bottom of the FAA Digital Products, “Terminal Procedures Search Results” page.

An icon will be incrementally added to airport approach plates, beginning Mar 5, 2015. The icon indicates a cold temperature altitude correction will be required on an approach when the reported temperature is, “at or below” the temperature specified for that airport. The one exception to this procedure is Chicago Midway Intl (KMDW). Only operations to 22L and 22R will be affected. Altitude corrections will not be required on any approach to any other landing runway at KMDW.

The affected airports list should be reviewed to determine relevance to each operator’s operations (airports), as well as which segment(s) of associated approaches will require an altitude correction. Temperatures for Cold Temperature Restricted Airports are completely separate from the temperatures published on area navigation (RNAV) approaches. Temperature restrictions on RNAV approaches for lateral navigation (LNAV)/vertical navigation (VNAV) minima must be followed, even if it is warmer than the temperature associated with the “snowflake” icon.

Mandatory compliance with these procedures will be in effect Sep 17, 2015.

FMI: InFO