Suicide by pilot
Suicide by pilot is an aviation event in which a pilot deliberately crashes or attempts to crash an aircraft in a suicide attempt, sometimes to kill passengers on board or people on the ground. This is sometimes described as a murder–suicide. It is suspected as being a possible cause of the crashes of several commercial flights and is confirmed as the cause in others. Generally, it is difficult for crash investigators to determine the motives of the pilots, since they sometimes act deliberately to turn off recording devices or otherwise hinder future investigations. As a result, pilot suicide can be difficult to prove with certainty.
Investigators do not qualify aircraft incidents as suicide unless there is compelling evidence that the pilot was doing so. This evidence would include suicide notes, previous attempts, threats of suicide, or a history of mental illness. In a study of pilot suicides from 2002–2013, eight cases were identified as definite suicides, with five additional cases of undetermined cause that may have been suicides. Investigators may work with terrorism experts, checking for links to extremist groups to try to determine whether the suicide was an act of terrorism.
A June 2022 Bloomberg News study of crashes involving Western-built commercial airliners revealed that pilot murder-suicides were the second most prevalent cause of airline crash deaths from 2011 to 2020, and that from 1991 to 2020, deaths due to pilot murder-suicides increased while deaths due to accidental causes significantly decreased. Furthermore, if China Eastern Airlines Flight 5735 is confirmed to be an intentional act, it will mean that deaths due to intentional acts have exceeded all other causes since the start of 2021. However, most cases of suicide by pilot involve general aviation in small aircraft. In most of these, the pilot is the only person on board the aircraft. In about half of the cases, the pilot had used drugs, usually alcohol or anti-depressants, which would normally have led to a flying ban. Many of these pilots have had mental illness histories that they have hidden from regulators.