In July 2006, Northwest Airlines flight attendants voted to replace their independent union with AFA. AFA's membership rose to 55,000 flight attendants. On November 4, 2010, AFA was decertified by the National Mediation Board as the bargaining representative for the pre-merger Northwest Airlines flight attendants of Delta Air Lines, after narrowly losing a representational election of the combined group the day before. AFA filed objections to the election with the National Mediation Board alleging interference. The National Mediation Board later dismissed those charges.