Southwest Airlines faces "operational emergency"

Presidents week has been tough for Southwest Airlines. Since Friday, the carrier has experienced more cancellations and delays than any other US airline.

About 100 flights were canceled for maintenance reasons, as the airline struggled to cope with the unusually high number of aircraft taken out of service for maintenance reasons.

In total, more than 40 aircraft per day were decommissioned, more than double the usual average and about 5% of the Southwest's fleet of approximately 750 aircraft.

Southwest is facing what its own managers call an operational state of emergency, due to the unusually high number of Boeing 737s of the airline that have been decommissioned for maintenance reasons.

In a memo obtained by CBS News, the airline asked everyone to stay on deck and warned that maintenance employees could be fired for unmotivated absences.

The out-of-service aircraft outbreak follows our "CBS This Morning" investigation into overpressure mechanics' complaints to get the aircraft up and running faster, reports correspondent Kris Van Cleave.

This motivated Friday's letter "state of operational emergency".

Such a statement is not unprecedented, but it is rare.

"I think that's an indication of problems," said John Goglia, a former member of the National Transportation Safety Board. "This kind of stress on the operation is not good. This does not bode well for the safety of the airline. "

A dozen southwest mechanics tell CBS News colleagues to feel emboldened to write problems following our investigation earlier this month in allegations of undue pressure on the Southwest mechanics.

Last week, Southwest also had to check 22 engines to make sure that the proper seals (or O-rings) of the fuel pump were installed.

The memo on "The State of Emergency Operational" was released just days after Senator Sens. Ed Markey and Richard Blumenthal. sent a letter following the CBS News survey on the FAA.

"Our top priorities are always safety," said Captain Dave Hunt, Southwest senior manager of security management, at CBS News last month. "I have the utmost confidence in the work of our mechanics and in the fact that any problem raised, all question, is handled appropriately. "

The airline is stuck in strained contract negotiations with mechanics that have been going on for years. The mechanics' union is concerned about the Southwest's state of emergency memo and "threat of termination". The memo gives the airline the opportunity to allocate longer hours of work and change staffing assignments.

The union fears that it "will increase the level of restraint and further degrade safety", because "technicians will be forced to work mandatory overtime regardless of … fatigue".

In a statement, Southwest said it was working to minimize the impact on customers of out-of-service aircraft.

The FAA indicated that it was closely monitoring the situation.