Mechanical Issues for Southwest Airlines Continue to Mount Since last week, the airline has cancelled hundreds of flights and delayed many more. A spokesperson says that the amount of planes that usually go in for repairs has doubled recently. Southwest adds that the planes have been affected for a variety of reasons. The issues come as the airline continues contract negotiations with the 'Aircraft Mechanics Fraternal Association.' The FAA is also currently investigating Southwest over its process for checking baggage weight data. The agency says "significant" mistakes may have led pilots to calculate the weight of an aircraft incorrectly. Should a plane takeoff with excess weight, the FAA says a variety of problems can be caused.