Southwest Airlines lost $60 million because of the government shutdown, the company said Wednesday.
That's far more than its original estimate of $10 to $15 million in losses, and it adds to a litany of recent problems for the airline.
On Tuesday, maintenance problems forced the airline to cancel 191 flights, or about 4% of its operation, according to data from FlightAware. The airline said more than 40 planes had maintenance issues, which is twice the daily average.
The mechanical issues are bad enough that the airline has canceled vacations for mechanics and is operating with "all hands on-deck." As of 9:45 am ET on Wednesday it had already canceled 404 flights for Wednesday and 23 for Thursday.
Besides the mechanical issues and the revenue hit, the Federal Aviation Administration is investigating the airline for the way it tracks the weight of checked bags on its flights.
The problems, described as "systemic and significant," caused pilots to miscalculate the weight of the plane at takeoff by as much as 1,000 pounds. That probe was first reported by the Wall Street Journal.
The airline told CNN that it is involved in an "ongoing effort to track and voluntarily report operational data to the FAA so that we can mitigate and eliminate any operational risks." But it said it has already put in place controls and procedures to address weight and balance issues.
Southwest was not the only airline to feel the pinch from the longest government shutdown in US history.
Delta Air Lines estimated last month that it would take a $25 million hit.
But the cascade of issues for Southwest has investors nervous. Shares of Southwest tumbled by 5% in early trading Wednesday.