FAA probes Southwest methods of calculating baggage weight

Federal officials have told Southwest Airlines to fix the way it calculates the weight of luggage loaded on flights after finding frequent mistakes during a yearlong investigation.

Southwest said Tuesday that it has made improvements in its methods for calculating the weight and balance of loads, and that it isn’t facing enforcement action.

The airline said that it voluntarily reported the issue to the Federal Aviation Administration last year.

The FAA investigation was first reported by The Wall Street Journal.

The newspaper said internal FAA documents showed that the airline made frequent mistakes in calculations and luggage-loading practices that could cause errors when pilots compute their plane’s takeoff weight.

Southwest told The Associated Press that ground workers manually count and record how many bags go on each plane. The airline uses FAA-approved average weights for bags and passengers, then adds the actual weight of fuel and freight to calculate each load. Southwest said it also builds in a safety margin.

The FAA found cases in which the bag load was more than 1,000 pounds heavier than paperwork indicated, the Journal reported.

Safety experts say pilots might respond incorrectly to an engine emergency if they had inaccurate information about the distribution of weight between front and rear cargo bays.

“It can be extremely critical,” Doug Moss, a retired United Airlines pilot, told the AP. “If the weight and balance is not calculated correctly, you could have a flight-control issue.”

Moss said pilots calculate the thrust and wing-flap settings for takeoff based on weight and other factors, and faulty data could lead pilots to put the thrust settings too low. That could be critical if an engine fails while the plane is still climbing, he said.