July 9, 2020

International operators should take note of recently revised procedures when operating in the North Atlantic (NAT). The primary changes concern Tango Routes – the routes between Northern Europe and the Spain/Canaries/Lisbon Flight Information Region.

First, state approval through a NAT High Level Airspace Authorization letter is now required to operate on Tango Routes.

Second, the procedures regarding transponder use have changed for the two easterly Tango Routes nearest the coast – T9 and T290. Typically, when entering into NAT airspace, pilots operate transponders continuously in Mode A/C Code 2000, except that the last assigned code is retained for a period of 30 minutes after entry into NAT airspace or after leaving a radar service area. However, when using T9 or T290, the pilot should instead retain the last assigned transponder code for only 10 minutes after joining one of these routes, then after 10 minutes switch to Code 2000.

This revised transponder procedure acknowledges the limited time spent in the NAT when flying these two routes.

“These are relatively simple changes and involve routes not commonly used by many U.S.-based NBAA members; however, it’s important pilots are aware of the new procedures,” said Mitch Launius, owner and instructor pilot at 30 West IP.

These new procedures are outlined in the revised North Atlantic Operations and Airspace Manual (NAT Doc 007) and are effective now. NAT Doc 007 Chapter 3 identifies route structures, including Blue Spruce Routes, with which international operators are most familiar, and Tango Routes. Section 6.8.1 describes the transponder procedure changes for T9 and T290.