Southwest's antiquated and atypical flight systems are partially responsible for cancellation chaos, airline experts say

• Southwest continued to cancel thousands of flights on Tuesday and into the rest of the week.
• Airline experts said the company is particularly vulnerable to a winter-weather breakdown.
• An outdated scheduling system and unique flight network structure exacerbated the problem.

Holiday travel mayhem continued to worsen this week as a wave of flight cancellations pummeled passengers across the country following a brutal winter storm.

Photos and videos of abandoned luggage, cranky customers, and exhausted employees consumed Twitter amid the nearly 5,000 canceled flights within the US on Tuesday.

The deadly winter storm that whipped through the country over the weekend ruined holiday plans for scores of travelers, but no airline was more impacted than Southwest, which canceled more than 60% of its flights on both Tuesday and Wednesday.

The company's cancellations accounted for more than 50% of all domestic cancellations on Tuesday, according to the flight tracking website FlightAware, resulting in a growing number of furiously-stranded patrons.

Airline analysts and industry experts told Insider and other outlets that Southwest's outdated scheduling system and atypical approach to mapping its flight network were partially responsible for the crisis.

Southwest bucks industry-standard in its flight network structure

Nearly every major airline uses a "hub and spoke" network, in which the company's planes are concentrated in a central location and fly out to one or two locations before returning to their main airport, said Helane Becker, an airline analyst at the investment bank and financial services company Cowen. For example, Delta has major hubs in Atlanta, Detroit, and Los Angeles, while United Airlines' planes are often flying into and out of Newark and Chicago-O'Hare, she told Insider.

Becker compared the approach to a bicycle tire, with a hub in the middle and several spokes leading out and away from the middle.

The "hub and spoke" approach allows airlines to halt individual travel routes amid poor weather, Henry Harteveldt told The New York Times, impacting as few people as possible.

But Southwest operates a "point to point" network, its aircrafts rarely returning to a central location, instead flying from one location to the next, Becker said. 

David Vernon, an airline analyst at the financial firm Sanford C. Bernstein, told The Times that the point-to-point system allows for a higher level of plane usage during normal operations, but can lead to widespread chaos amid winter weather. When dangerous conditions ground "point to point" planes in multiple regions, it can have a cascading effect on the airline's future flights all across the country, evidenced by the near nationwide distribution of Southwest cancellations throughout the US this week. 

Airlines operating on a "hub and spokes" model also have the advantage of calling upon their reservist crews, employees who are typically concentrated near the hub, when extra help is needed, Becker said.

A spokesperson for Southwest in a statement to Insider acknowledged the company's unique approach.

"Southwest stands alone in the industry as the largest carrier in 23 of the top 25 travel markets in the U.S," Chris Perry said. "We are not a hub and spoke carrier; we have 30+ airports with high flight volume so our solution to normalize the operation looks very different from other carriers."

Staffing shortages and an outdated scheduling system also bear blame, experts say

The crisis comes amid heightened tensions between Southwest management and employees over staffing shortages, Robert W. Mann Jr., a former airline executive, told The Times. Pilots can only fly up to eight hours per 24-hour period or up to 10 hours if a second pilot is aboard, while flight attendants are guaranteed a 10-hour rest period in between flights.

The time regulations for airline crew, while necessary for safety, have exacerbated the current crisis at Southwest, Becker said: "People are running out of time" and ending up stranded in cities and airports where they aren't scheduled to work.

The problem has been further inflamed by Southwest's scheduling system. Becker suggested that Southwest has underinvested in its information technology in recent years and is now reaping the consequences.  

Whereas most other airlines use an automated employee app to track staffers' locations in real time, Southwest's scheduling system assumes where employees are located based on their flight assignments. As delays and cancellations piled up, more and more Southwest staffers found themselves fighting to get to their destinations.

"They can't get through" on the phones for reassignment or rescheduling, Becker said. 

A Southwest spokesperson said the company is focused on investing in technology upgrades to avoid problems like this in the future.

"Our technology struggled to align our resources due to the magnitude and scale of the disruptions," Perry told Insider. "In our desired state, we will have automation that can handle Crew reassignments quickly and efficiently."

The fiasco will have long-term consequences

As Southwest continues to cancel flights days in advance, Becker predicted the crisis is likely to be ongoing through the end of the week. The company announced Tuesday that stranded passengers won't be able to rebook their flights until Saturday, December 31. 

"The fact that they're not taking any reservations until next year, at this point, means the impact is going to last until next year," Becker said.

She said it's possible that the airline will have to fly empty planes around the country picking up stranded crew members and bringing them to where they need to be before they can restart normal operations.

There are significant financial implications for Southwest as the company prepares to reimburse and rebook passengers with rescheduled flights, meal, hotel, and travel vouchers, and refunds.