Passengers wait for the flights to resume at Hartsfield-Jackson Atlanta International Airport in Atlanta
Southwest Air Lines ticket agents check-in passengers at Hartsfield-Jackson Atlanta International Airport after the Federal Aviation Administration (FAA) had ordered airlines to pause all domestic departures due to a system outage in Atlanta, Georgia, U.S. Reuters

Southwest Airlines Chief Operating Officer Andrew Watterson will testify on Feb. 9 before the U.S. Senate Commerce Committee after a holiday meltdown forced the budget carrier to cancel thousands of flights.

The hearing titled "Strengthening Airline Operations and Consumer Protections" will also include Southwest Airlines Pilots Association President Captain Casey Murray, Sharon Pinkerton, a senior official with Airlines for America, an industry group, and Paul Hudson, who heads Flyers' Rights, a passenger advocacy organization.

The committee had asked Chief Executive Bob Jordan to testify, a person briefed on the matter told Reuters, but Southwest told Reuters "unfortunately, the date that was selected for the hearing next week overlapped a previous commitment for Bob."

The hearing will review causes and impacts of recent air travel disruptions including the Southwest December holiday operational woes that resulted in more than 16,000 flight cancellations.

Jordan has repeatedly apologized for the mass cancellations and said the carrier is looking at all options to prevent a repeat.

Southwest said, "Andrew has been working in lockstep with Bob as Southwest manages recovery efforts. As Southwest's chief operating officer, Andrew is exceptionally well positioned to address the topics covered at the hearing."

Pilot's union head Murray told Reuters in December that "Southwest is using outdated technology and processes, really from the '90s, that can't keep up with the network complexity today."

COO Watterson said last month that the airline's crew scheduling software did not stop working, "but a combination of our processes and the technology couldn't keep up with the pace of cancellations at the height of the weather disruption."

Southwest is facing a lawsuit from shareholders and regulatory scrutiny over its flight scheduling and handling of more than 16,700 cancellations that disrupted travel plans for about 2 million customers during a busy holiday season.

The U.S. Transportation Department (USDOT) is investigating whether Southwest engaged in "unrealistic scheduling of flights" in December. USDOT has forwarded thousands of complaints it received to Southwest.

In a Reuters interview this week, U.S. Transportation Secretary Pete Buttigieg declined to detail what investigative steps USDOT had taken in the Southwest probe but said "we're really looking at several things at once."

Buttigieg said his immediate focus is "making sure the passengers who got caught up in this are made whole."

Travelers deal with weather cancellations at Dallas Love Field Airport
Southwest Airlines passengers wait in line at the baggage services office after U.S. airlines, led by Southwest, canceled thousands of flights due to a massive winter storm which swept over much of the country before and during the Christmas holiday weekend, at Dallas Love Field Airport in Dallas, Texas, U. Reuters