Thanksgiving is one of the busiest travel periods in the US airlines' calendars. But Delta Air Lines has canceled hundreds of flights, upending thousands of passengers' travel plans. It's a blow to the reputation of Delta Air Lines and a blow to passengers over what's going to be the busiest weekend for airlines in a long time.

131 Delta flights canceled on Friday

Gary Leif of View From The Wing has crunched the numbers and reckons Delta Air Lines has canceled approximately 420 flights over the Thanksgiving weekend, including 254 flights on Thursday, November 26. According to FlightAware, Delta has canceled 131 flights on Friday, November 27. On Saturday, November 28, a further 28 flights will not take off. No data is available yet for Sunday, November 29.

In contrast, United Airlines has canceled ten flights today (Friday), JetBlue has canceled six flights, American Airlines has canceled five flights, and Allegiant Air has canceled four flights.

Simple Flying's Jay Singh told National Public Radio's Mary Louise Kelly on Wednesday that this weekend was shaping up to be the busiest weekend for US airlines since March. Over one million passengers passed through TSA checkpoints last Sunday. Over the Thanksgiving holiday period, Jay Singh said daily passenger movements of 1.1 to 1.2 million were likely.

And while these numbers fall far short of what airlines could normally expect over the Thanksgiving weekend, it's a sign that numbers are trending in the right direction for US airlines.

Stay informed: Sign up for our daily aviation news digest.

Delta-thanksgiving-cancelation-chaos
This weekend is shaping up to be the busiest for US airlines since March. Photo: Denver International Airport

What's going on at Delta Air Lines?

So what's going on at Delta Air Lines? Over this weekend, of all weekends, why would Delta be canceling so many flights when it's business as usual at their competitors?

There's speculation industrial relations unrest is behind it. Earlier this week, Delta Air Lines pilots voted in favor of pay cuts to avoid furloughs until 2022. Approximately 1,700 Delta pilots were due to get the ax at the end of November. This week's deal avoided that. But Matthew Klint in Live & Let's Fly thinks there might still be an under the radar industrial relations campaign going on at Delta.

"With jobs protected, could it be that pilots simply decided to call in sick? It seems counterintuitive considering pilots overwhelmingly ratified the compromise, and no jobs will be lost, but it could be an expression of resentment over the pay cuts coming to all pilots."

Delta-thanksgiving-cancelation-chaos
Photo: Los Angeles International Airport

A combination of factors?

Delta isn't saying much about the cancelations. In a statement seen by Simple Flying, a Delta spokesperson said;

"Delta teams are working diligently to prevent flight cancellations this week. A number of factors have pressured our ability to timely staff several dozen scheduled flights on Wednesday. We apologize for any inconvenience this may cause our customers."

Various commentators speculate that a couple of issues are combining to cause havoc with Delta's schedules this Thanksgiving period. Firstly, the airline had too few staff rostered on in the first place, giving it no padding when people called in sick. Secondly, if the industrial relations theory is correct, far more employees called in sick than Delta had planned for. Both Delta management and the pilot's union spoke of this week's deal to avoid furloughs in glowing terms. But there's apparently a great deal of resentment in the ranks about the threat of reduced hours and pay cuts.

Meanwhile, Delta Air Lines says most affected passengers are getting switched over to other same day flights.