During the NTSB 's renewed investigation , it was determined that the crash of Flight 585 ( and the later Flight 427 crash ) were the result of a sudden malfunction of the aircraft 's rudder power control unit . Another incident ( non-fatal ) that contributed to the conclusion was that of Eastwind Airlines Flight 517 , which had a similar problem upon approach to Richmond on June 9 , 1996 . On March 27 , 2001 , the NTSB issued a revised final report for Flight 585 , which found that the pilots lost control of the airplane because of a mechanical malfunction . The renewed investigation concluded with a " probable cause " that stated : The Discovery Channel Canada / National Geographic TV series '' Mayday '' dramatized the crash of Flight 585 and the subsequent 737 rudder investigation in a 2007 episode titled '' Hidden Danger ''
Eastwind Airlines Flight 517
Eastwind Airlines Flight 517
United Airlines Flight 585