Flight data recorders and cockpit voice recorders were not fitted to all RAF Chinooks at the time of the accident. The absence of this data greatly reduced the amount and quality of data available to subsequent investigations. Information on speed and height were derived from the position of cockpit dials in the wreckage and the wreckage's condition. During 1994, the RAF had begun to fit these recording devices across the Chinook HC.2 fleet prior to the accident; this process was completed in 2002.