Alaska Air Group (ALK) strengthened its position as the fifth-largest U.S. airline by revenues when it completed the acquisition of Hawaiian Airlines for $1 billion in cash. ALK also assumes about$900 million in Hawaiian debt. The acquisition was completed a day after the last major regulatory obstacle to the deal was overcome when the Department of Transportation or DOT cleared the transaction.The DOT approval did not come without any strings attached to it. The conditions laid down by the regulatory auth ...