How some flights were exempt from the US ground stop

Detailed summary

How some flights were exempt from the US ground stop, including international, Hawaii and medical aircraft departures. Read more at straitstimes.com.

Some international flights, West Coast flights to Hawaii, and routes to Alaska still flew during the ground stop because they used separate air traffic centres and oceanic airspace.

NEW YORK - Thousands of passengers scrambled to update their travel plans on Nov 14 as air traffic slowly unsnarled after a nationwide ground stop on Nov 13, but a number of travellers had already arrived at their destinations on flights left unaffected by the order.

Dozens of international flights took to the skies even as airports across the United States coped with only the third nationwide ground stop issued by the Federal Aviation Administration this century. Certain flights were also permitted to depart from the West Coast to Hawaii during the stoppage.

Here’s why some air travel was allowed to proceed even as flight systems were hampered.

More than 8,200 flights were cancelled nationwide on Nov 13 – over 31% of those scheduled – according to Cirium, an aviation data firm.

But more than 60 flights bound for overseas left the United States during the stoppage, according to Flightradar24, an aviation tracking site.

There are 21 air traffic control facilities, 20 in the contiguous United States and one in Alaska, that oversee swaths of regions throughout the country, according to the FAA.

As some of those centres recovered, flights were “allowed to depart through coordination with the Air Traffic Control System Command Center”, the FAA said in an advisory less than two hours after the ground stop was ordered.

Flights departing for Europe from the Midwest or the East Coast can communicate with the Canadian authorities, said Dan Bubb, a former commercial pilot and an aviation history professor at the University of Las Vegas, Nevada.

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