An American Airlines passenger jet prepares to land at Dallas-Fort Worth International Airport in Grapevine, Texas, in this July 17, 2007 file photo. American Airlinesplans to announce Monday May 11, 2009,  it will let frequent fliers use miles to book one-way trips for half the miles of a round trip. AP Photo logo AP Photo 6 months ago

An American Airlines passenger jet prepares to land at Dallas-Fort Worth International Airport in Grapevine, Texas, in this July 17, 2007 file photo. American Airlinesplans to announce Monday May 11, 2009, it will let frequent fliers use miles to book one-way trips for half the miles of a round trip.