The Federal Aviation Administration (FAA) is investigating a Southwest Airlines flight that dropped to around 500 feet from the ground earlier this week during a missed approach while landing at Oklahoma City's Will Rogers World Airport, reports say.  Data from the flight-tracking website FlightAware shows that the Boeing 737-800 passenger jet was flying low over Yukon – a city on the outskirts of Oklahoma City – around midnight on Wednesday before gaining altitude, circling around and landing about 10 minu ...