American Airlines parent AMR, one of the few major U.S. airlines to avoid bankruptcy, finally succumbed Tuesday and filed for chapter 11. AMR said that all of its subsidiaries will honor tickets and reservations and operate normal flight schedules during the bankruptcy process. The airline also announced that Gerard Arpey, its chairman and CEO, is retiring. He is being succeeded by Thomas Horton, who said at a press conference that Arpey had opposed the bankruptcy filing. More Here