Mesa Air Group has been buying US Airways stock since September, according to Mesa's annual 10-K report that was filed with the SEC on Friday. Mesa operates some Express flights for US Airways. Mesa helped form an investment company, UFLY, to buy US Airways stock for itself and others, according to the SEC filing. As of Sept. 30, other investors had pledged $2.6 million to UFLY (Mesa owns 50% of UFLY). I wonder if the U in UFLY has anything to do with U.