A pilot who intentionally crashes or attempts to crash an aircraft in an attempt to commit suicide, often with the intention of killing other people on board or on the ground, is said to have committed suicide. This is occasionally referred to as a murder-suicide. It is known to have caused some commercial aviation crashes and is likely to have contributed to others. In general, it is challenging for crash investigators to pin down the pilots’ intentions since they occasionally take deliberate actions to obstruct recordings or other inquiries. Pilot suicide is therefore sometimes impossible to establish with absolute certainty.