The plane was too badly damaged to determine a definite cause . Canadian aircraft were not required to carry voice cockpit recorders or flight data recorders at this point , complicating the investigation into the crash of TCA Flight 831 . The official report released in 1965 pointed to problems in the jet 's pitch trim system ( the device that maintains a set nose-up or - down attitude ) as a possibility , since a pitch trim problem caused the similar crash of Eastern Air Lines Flight 304 , another DC-8 , three months later in 1964 . Other possible causes were put forward that could not be ruled out : 1 ) Icing of the pitot system ; and 2 ) Failure of the vertical gyro
Eastern Air Lines Flight 304
Eastern Air Lines Flight 304
Trans-Canada Air Lines Flight 831