Southwest Airlines planes parked at Gates D4 and D6 in Terminal 4 of the Sky Harbor International Airport, Friday, Dec. 30, 2022, in Phoenix. (Kirby Lee via AP)
CNN  — 

Congress is set to receive new evidence Thursday of internal chaos at Southwest Airlines over the Christmas holiday meltdown.

The pilots’ union is prepared to characterize the operation as held together by “duct tape,” while Southwest’s chief operating officer is expected to apologize and say the airline “is intensely focused on reducing the risk of repeating the operational disruption.”

Among the union’s evidence is a message sent during the meltdown to a cockpit computer from the airline’s dispatchers asking what crew is onboard the plane.

“Sched is asking to confirm who is operating this flight,” the message read. “Pls send emp numbers to confirm. It’s a mess down here.”

A photograph of the message, which shows the extent of the airline’s breakdown, is included in testimony the Southwest Airlines Pilots Association union, SWAPA, plans to present at a Senate Commerce committee hearing. (The message and others are seen in all capital letters, standard for this