Flight crew was ‘mentally set’

Press, 22 October 1980, Page 3

Flight crew was ‘mentally set’

PA ’ Auckland The crew .of Flight TE9OI was mentally prepared to fly a route to the west of Ross Island and not over Mount Erebus, the DCIO crash inquiry heard yesterday. This conclusion was given by Professor Ross Henry Day, an expert on human perception and foundation professor of psychology at Monash University, Melbourne, when he gave evidence yesterday. Professor Day desbribed what he called a “mental set” — the fact that human beings’ perceptions were determined largely by their expectations, set up by ex-i perience. He said after studying the accident report and briefing procedures given to the crew that it was reasonable to conclude that the crew were “mentally set” for an’ approach west of Ross Is-, land down McMurdo Sound. | He said this conclusion; was based on a number fac-i tors. These included: A slide shown at the; audio-visual briefing show-1 ing a track to the west of; Ross Island. Charts and maps, all of which indicated a ciear track] to the west of Ross Island. ; Evidence that the atten-l tion of pilots who attended l

DC 10 CRASH INQUIRY

: the briefing on November 9 ! was not drawn to the fact I that the rotite would pass over Mount Erebus. ; j Professor Day said the [failure to emphasise that the ! route was directly over l Mount Erebus would have contributed to the state of expectancy set up in the minds of the crew that the ! route was westwards of Mount Erebus. ! He said the crew’s state of imind would have been such’ as to search out route features associated with the! tract west of Ross Island. I Professor Day said a similarity of landmarks and cliff! faces could have been taken las confirmation by the crew

• that the route they were fly-' ! ing was ro the west of. Mount Erebus. I He also said that low • cloud cutting across the mountain and "sea fog ob[scuring the ice -cliffs would .have contributed to the rec-’ jognition of a false horizon [by the crew. j I Professor Day was asked i this year by Captain Gordon ■ Vette and counsel for the estate of Captain T. J. Collins; ! to present his views on the 1 i problems of visual per-j Iception. j Under cross-examination • iby Mr John Henry, Q.C. .counsel for the consortium; of passengers’ families, Pro-! jfessor Day said he had notj had any Antarctic ex-! perience. He said his main! concern was with examining! the flight crew’s perceptualsystems functioning, based! on known evidence, verba? data, and various maps and; photographs. He did not think his abil-j ity to assess this functioning! was impaired bv a lack of; personal experience. The inquiry adjourned yesterday to November 17 to; enable Mr Justice Mahon | and counsel assisting the; commission, Mr W. D. Ba-i ragwanath, to travel over-! seas to further their in-| quiries.