On May 25, 2003, a Boeing 727-223 airliner with the registration N844AA was taken from Quatro de Fevereiro Airport in Luanda, Angola. This incident triggered a global search by U.S. law enforcement and intelligence agencies. 

To this day, no trace of the aircraft has been discovered https://pbs.twimg.com/media/GZRb0ecX0AIGbvr.jpg