Feb. 18 (UPI) -- The Federal Aviation Administration is investigating Southwest Airlines for failures to accurately track the combined weight of checked bags loaded onto its airplanes.
The FAA discovered systemic mistakes with employee calculations and the airline's luggage-loading practices which led to inaccuracies in pilots' computed takeoff weights, ranging from a few dozen pounds to more than 1,000 pounds in excess of what paperwork indicated, The Wall Street Journal first reported.
An FAA representative confirmed the yearlong investigation to both The Wall Street Journal and USA Today, adding it has advised the airline on how to rectify the issue.
"The FAA has directed the development of a comprehensive solution to the methods and processes used by Southwest Airlines to determine this (weight and balance) performance data," the spokesman said. "The FAA will not close its investigation until it is satisfied that Southwest's corrective actions are consistent and sustained."
FAA officials estimated that at certain times up to one-third of Southwest's roughly 4,000 daily flights may have operated with inaccurate weight data, although the Southwest spokesman said there is no current information to support the estimate, "especially given the controls and adjustments that we've implemented."
A Southwest spokesman told The Wall Street Journal that it has cooperated fully with the FAA and voluntarily reports issues to enhance safety.
He added that the airline's interactions with the FAA "do not constitute findings of non-compliance" and the agency hasn't imposed fines or taken any other formal enforcement action.
While most airlines use computerized scanners to count bags, Southwest relies on its ground crews to tally the bags. Both methods of counting then rely on average bag weight to calculate the overall weight of checked luggage.
Southwest spokeswoman Brandy King told USA Today the airline switched to a new system approved by the FAA in August 2017 to improve reliability, efficiencies and accuracy, and made more changes in 2018.
In 2019, Southwest plans to adopt the widely used process of scanning each bag as it's loaded onto the plane, after testing it at three airports in 2019.
"While no system can ever be perfect, our weight and balance program is a proven, reliable system with checks and balances installed to ensure safe operations by any measure or standard," King said.