Another significant change, said Launius, is that oceanic flights “will no long have room to turn right, descend 500 feet, and reverse course 180 degrees.” With the narrower lateral boundaries, as of Nov. 5, “If you want to go back or divert to an alternate, you must first descend below Flight Level 290 or climb above Flight Level 410.”
Pilot judgment determines the sequence of actions, and operators should take action as necessary to ensure safety. When able, they should communicate with ATC via voice or CPDLC, squawk 7700 as appropriate, and select the appropriate emergency functionality on ADS-B or ADS-C, if so equipped, and they should establish communication with nearby aircraft on 121.5 MHz.
Other changes cover the most frequent in-flight contingency procedures, such as a medical emergency, an aircraft system problem such as loss of pressurization or a significant reduction of navigation capability where performance accuracy is a prerequisite for safe flight operations. Also covered is inability to comply with an assigned oceanic clearance due to weather.
The new contingency procedures were the subject of an 18-month test in the North Atlantic flight information region, Launius said
“ICAO determined the test a success after a year and will incorporate them into Document 4444, the worldwide standards for air traffic management,” he added. “On Nov. 5, the FAA will apply them in the Oakland and Anchorage flight information regions, the world’s largest blocks of oceanic airspace.”