ARGUED SEPTEMBER 30, 2011
Before EASTERBROOK, Chief Judge, and POSNER and WILLIAMS, Circuit Judges.
The McCaskill-Bond Amend- ment to the Federal Aviation Act, 49 U.S.C. §42112 note, provides that a transaction “for the combination of multiple air carriers into a single air carrier” requires the combined business to merge the seniority lists of the two carriers’ employees. Republic Airways Holding acquired Midwest Airlines in July 2009 by purchasing its parent, Midwest Air Group. The seniority lists for mechanics, baggage handlers, and administrative per- sonnel have been integrated under the Amendment. But Republic furloughed the flight attendants, requiring them to apply for “new” jobs; if they are rehired, the Teamsters Union, which represents the flight atten- dants at Republic’s older carriers (Republic Airlines, Chautauqua Airlines, and Shuttle America), places them at the bottom of its seniority roster. (Pilots, too, were furloughed, but their status is not at issue here.) The Teamsters Union has refused to budge from this posi- tion, which it has maintained even after the National Mediation Board concluded that the flight attendants who worked for Midwest became part of a single bar- gaining unit at an integrated air transportation business that comprised Republic, Chautauqua, Shuttle America, and Midwest. In re Chautauqua Airlines / Shuttle America / Republic Airlines / Midwest Airlines / Frontier Airlines / Lynx Aviation, 37 N.M.B. 148 (2010). Three of Midwest’s flight attendants, and a committee purporting to speak for all of them, filed this suit.