Southwest Airlines on Friday declared a "state of operational emergency," after an unusually high number of aircraft put out of service over the last several days.
The Dallas-based airline issued the news in a memo to its maintenance technicians and inspectors in Phoenix, telling employees they would have to provide a doctor's note if they call in sick in a push to "maximize the number of mechanics available for work," the company said in a statement.
In the statement, Southwest said, on an average day the airline plans to have as many as 20 out of its 750 aircraft unavailable for maintenance. This week, the percentage of out-of-service aircraft has more than doubled the daily average.
"To take care of our Customers, we are requiring all hands on deck to address maintenance items so that we may promptly return aircraft to service," the company statement said. "At the same time, our operational planners have been working in the background to minimize the impact to our Customers."