The report said a major distraction of unknown cause cannot be discounted as a factor in the crash. The report has come to light as a House of Lords committee holds a final hearing this week into whether two RAF air marshals were justified in finding the two special forces pilots of Chinook ZD576, Rick Cook and Jonathan Tapper, grossly negligent.
The report is being considered by the committee which has devoted part of its hearings to considering the possibility that a problem with the Chinook's Fully Automated Digital Electronic Control (Fadec) computer system, or other malfunction, could have been a factor in the crash.
The Lords committee was formed after a campaign by Computer Weekly and Channel Four News to show that there are doubts over the cause of the crash, particularly in the light of the aircraft's history of serious problems involving its Fadec fuel control system.
The newly-disclosed report was a study of how, in the light of technical evidence from the wreckage, human failings could have led to the accident.
The author of the report, John Chappelow, principal psychologist at the Defence Research Agency's Centre for Human Sciences, part of the Ministry of Defence, did not rule out human failings. But "firm conclusions are not possible and a major distraction of unknown cause cannot be discounted," he added.
The report's finding is at odds with the verdict of two air marshals, who have told the committee that the pilots of ZD576 were, without doubt, grossly negligent.
The committee is due to publish its findings by January 2002.