The following CVR records indicated that the captain was trying his level best to regain control the flight. The FDR and the CVR stopped recording at 0150:36. 64 EST and 0150:38. 47 EST with its last indication that the elevators remained in a split condition. The rest of the flight information was gathered from the two debris fields recorded radar data. Primary radar data demonstrate that the descent of the aircraft had stopped at it had climbed to 25,000 feet above msl before going into another descent which resulted into its impacting on the surface of the ocean.
The Safety Board’s assessment of the data from the National Climatic Data Center National Radar Mosaic and other meteorological sources during the flight time discovered that there was no evidence of noteworthy aberrations in atmospheric condition in the accident area. Also, no pilot reports indicative of any important meteorological experience were filed in that area. (National Transportation Safety Board, 2002)
There were no facts substantiating any failure scenarios in the elevator system of the accident aircraft which could have caused or kicked in the initial pitchover or hindered a successful recovery. Even if one of the examined failure conditions that the in depth mechanical investigation had assessed set in, the aircraft could still have been retrievable owing to the redundant elevator system of the Boeing 767’s. Thus it could be concluded that the aircraft’s nose-down movements were not due to a malfunction in the elevator control system or an outcome of some other mechanical failure.
Prior research experiences demonstrate that fundamental frequency along with speech rate differ in traits among speakers and often disclose information relating to the mental anxiety of the speaker. Thus, the Safety Board uses guidelines devised on the basis of the above fact to assess the level of psychological pressure a speaker goes through. Based on these guidelines, the CVR speech examination indicated that the relief first officer displayed an increase of about 25 percent in fundamental frequency during the crisis sequence, as compared to his normal voice frequency.
However, the speech assessment also revealed that the command captain demonstrated a 29 percent increase in his fundamental frequency while he reentered the cockpit after his visit to the toilet and an increase between 47 and 65 percent when he was trying to regain control of the flight. As indicated by the CVR and the FDR the relief first officer was the only person in the cockpit when the autopilot was disengaged manually and the throttle was moved from cruise settings to idle mode.
There was no indication of inconsistent air traffic, or other events that would have prompted the initial descent. The characteristics of the consequent nose-down elevator motion could only be elucidated by inputs provided by the pilot. The lack of any effort by the relief first officer to recuperate from the aircraft’s sudden dive is also incoherent with his natural reactions that should have been exhibited when encountering an abnormal flight condition. (Washington, 2006)