The United Airlines Flight 663 incident was a "minor international incident" in 2010 involving a Qatari diplomat on the leg of a United Airlines flight from Ronald Reagan Washington National Airport (Washington, DC) to Denver International Airport (Denver, Colorado). The diplomat prompted a mid-air terrorism alert after smoking in the aircraft lavatory, which led the Qatari government to recall him two days later.United no longer uses Flight 663 as a DCA-DEN-LAS route. UA663 is now used on the Eugene-Denver route, flown by an Airbus A320.