December 2017 –

Data Communications or Data Comm — a technology that supplements voice communications between air traffic controllers and pilots with digital text-based messages — is helping Southwest Airlines get off the ground faster at airports across the country.

Southwest operates 4,000 flights-per-day. "Forty-eight of the 55 airports with Data Comm-capable air traffic control towers happen to be at airports where Southwest services," said Richard Dalton, director of airspace and flow management at Southwest Airlines. "So, we get a lot of exposure to this opportunity which we see fitting in beautifully to the modernization of the airspace system."

Of the more than 5,000 Data Comm operations-per-day at U.S. airports, 2,300 — or about 45 percent — represent clearances issued to Southwest aircraft. With Data Comm, air traffic controllers and pilots can transmit flight plans and other essential information digitally as typed messages rather than through complicated radio voice exchanges.

Voice transmissions can take up to a few minutes because once the air traffic controller verbalizes the information to the flight crew, the pilot must repeat it back correctly. If not, they must continue to trade voice exchanges until both confirm the same information. Meanwhile, other flight crews are waiting for the radio frequency to clear so they can have their turn to receive, repeat, and confirm clearances from air traffic control.

By contrast, Data Comm allows air traffic controllers to send pilots instructions to read, accept, and load into their flight computers with the push of a button. Getting flights into the air more efficiently helps airlines stay on schedule and enables passengers to meet connecting flights. As an additional benefit, pilots and controllers can spend more time on other critical tasks, which improves efficiency and enhances safety.

Data Comm is particularly useful when re-routes are issued, for example, during times of high congestion or to avoid a major weather event. A re-route means another round of instructions from air traffic controllers, and some situations may require multiple re-routes.

Southwest conducted a study to determine exactly how Data Comm is impacting its operations during re-routes. In conjunction with Data Comm contractor Harris Corp and the NextGen Advisory Committee's Joint Analysis Team (JAT) — operational and analytical experts from the FAA and aviation industry — the airline reviewed more than 300,000 flight records from May 1 to July 31 of 2017.

The airline found route clearances issued through Data Comm saved Southwest an average of 52 seconds in taxi-time compared to aircraft receiving traditional voice clearances. Some airports, such as McCarran International Airport in Las Vegas and Baltimore-Washington International Airport, saw even bigger time savings.

Just under a minute of savings might not sound like much but Dalton says it can make a real difference. "This is a game of minutes and inches," he said. "Those increments of time saved add up." It often means planes can take off ahead of aircraft not equipped for Data Comm. "We've seen cases where we've been in line with non-Data Comm flights and because we were able to process a route revision very quickly, we were sequenced around airplanes that were still reviewing their new clearances — because air traffic control didn't want the capacity there to go unutilized," Dalton said.

Dalton says time saved will increase even more as airlines continue to equip. Currently, about 3,900 aircraft operating in U.S. airspace have Data Comm technology installed. Southwest says 525, or about 73 percent, of its 715 aircraft are equipped. Dalton says Data Comm is going to make the nation's airspace more efficient for the traveling public and help minimize delays.

The benefits of Data Comm are expected to be even greater for air carriers and passengers when air traffic controllers can use Data Comm to communicate with aircraft at cruising altitude. These services are scheduled to begin in 2019 and be available across the country by 2021.