Southwest Airlines flight attendants blame company leadership for thousands of stranded holiday travelers. Southwest has canceled nearly 16,000 flights since December 22, including more than 2,300 flights already canceled for today. However, TWU Local 556 President Lynn Montgomery, Southwest leadership could have prevented the ordeal had they followed advice from the union. Montgomery cites outdated flight crew scheduling methods and antiquated computer systems as the main culprit in stranding thousands of holiday travelers across the country.