Southwest Airlines continues to face an "operational emergency" after the unusually high number of aircraft that have been decommissioned.
The Dallas-based airline has been forced to cancel hundreds of flights since the end of last week due to mechanical issues with its fleet. Despite a "everyone on deck" staffing policy for its mechanics, the company was not able to solve its problems.
In a statement Tuesday, Southwest said there was no common theme to the problems its 750 planes were facing and that it was extending the staffing protocol introduced last week to " maximize the availability "of mechanics.
"We need all the people on the bridge to solve maintenance problems so we can quickly return the aircraft to service and take care of our customers," he said.
Tuesday, more than 40 aircraft had maintenance problems, more than double the average of a given day. This created a domino effect, disrupting southwestern flights across the country.
According to FlightAware, Southwest Airlines canceled 186 flights on Tuesday, about 4 percent of its operations. 730 additional flights were delayed.
Maintenance problems of the airline The US Federal Aviation Administration is investigating how Southwest tracks the weight of checked baggage on its flights.
The FAA began its investigation in February 2018, the FAA told CNN Business on Monday.
The Wall Street Journal, which first recounted the story, said FAA officials and agency documents said the airline's employees had made mistakes that had led pilots to calculate the incorrect weight of planes taking off.
The errors were described as "systemic and significant", resulting in take-off weights reported to be 1,000 pounds lower than the actual weight of the aircraft.
Southwest said in a statement to CNN Business that it "is pursuing efforts to voluntarily track and communicate operational data to the FAA so that we can mitigate and eliminate operational risks."
But the airline added that she had already put in place controls and procedures to solve the problems of weight and balance. Southwest said it shared these measures with the FAA.