Boeing 737 rudder issues

During the 1990s, a series of issues affecting the rudder of Boeing 737 passenger aircraft resulted in multiple incidents. In two separate accidents, pilots lost control of their aircraft due to a sudden and unexpected rudder movement, and the resulting crashes killed everyone on board, 157 people in total. Similar rudder issues led to a temporary loss of control on at least one other Boeing 737 flight before the cause of the problem was ultimately identified.

The National Transportation Safety Board determined that the incidents were the result of a design flaw that could result in an uncommanded movement of the aircraft's rudder.^{: 13 : ix}

The issues were resolved after the Federal Aviation Administration ordered modifications for all Boeing 737 aircraft in service. In 2016, former NTSB investigator John Cox stated that time has proven the NTSB correct in its findings because no additional rudder-reversal incidents have occurred since Boeing's redesign.