Navigation error reported shortly before Erebus crash

Press, 15 July 1980, Page 3

Navigation error reported shortly before Erebus crash

PA Auckland The commission of inquiry into the Mount Erebus crash learned yesterday that an error in navigational computer tapes had been discovered by an Air New Zealand pilot who commanded an Antarctic scenic trip on November 14 last year, exactly two weeks before the Erebus crash. The Chief Inspector of Air Accidents, Mr R. Chippindaie, said the pilot was flying down the east coast of the Antarctic continent towards Ross Island when he noticed that the position of McMurdo Base appeared to be incorrect on the navigational computer. He flew over the TACAN (a navigational aid at McMurdo base) and attempted to update the computer to match the reading. Checking the readings at "way points” — , checking references — on the return flight he found the computer was out by two degrees and 10 minutes. He told Air New Zealand about the error.

Asked by the inquiry commissioner, Mr Justice Mahon, what the error represented in distance, Mr Chippindale said 24 miles. At one stage, while being cross-examined by Mr C. M. Nicholson, Q.C., appearing for the passengers’, consortium, Mr Chippindale said he was not aware that any of the crews he had interviewed had approached McMurdo on track.

Mr Chippindale, still answering questions, said he was aware of a report from Antarctica which claimed that some sightseeing aircraft were flying low over the continent. One was observed about 1000 ft above glacier level. He did not know the identity of the aircraft concerned.

“The report had been in the nature of a diplomatic reminder and I left it that way,” said Mr Chippindale. Mr Chippindale said a DCIO could be flown at 1500 ft above sea ice in the Antarctic, using the aids the aircraft had to detect its height above ground. Mr Chippindale had been asked by his Honour, assuming it was a clear day with perfect visibility, would it really matter if the aircraft flew below GOOOft.

Expressing reluctance to answer the question on the grounds it was outside his realm of expertise, Mr Chippindale said if the environment was settled and there was no cloud and a .bright sun, low level flight might

be permissible in the area around McMurdo.

He then suggested an altitude of 1500 ft over sea ice. Cross-examined by Mr R. L. MacLaren, who appeared for the family of the first officer of Flight TE9OI, Gregory’ Mark Cassin, Mr Chippindale said he regarded the Antarctic flights as an opportunity for sightseeing. As a sightseeing trip, said Mr MacLaren, the briefing allowed the crew to permit passengers to visit the flight deck at low altitude. “I believe the instruction is that visitors to the flight deck should be carefully controlled, particularly during low-level flight.” said Mr Chippindale.

Answering a further question, Mr Chippindale said he

was not prepared to state whether low-level flight

would provide better sightseeing for passengers. When it was suggested that 6000 ft would not give "much of ' a view’” of McMurdo, Mr Chippindale said the high ground speed of the aircraft in a “clean” configuration in many instances might give a better view from that height.

Earlier in the hearing, while being cross-examined by Mr Nicholson, Mr Chippindale said First Officer Graham Neville Lucas appeared to use the aircraft radio onlv once during the flight from Auckland to Ross Island, where the plane crashed.

While flight TE9OI was in the Cook Strait area he talked to a person representling Helicopters (N.Z.), Ltd, about a map and ice conditions in part of the Antarctic.

The company was apparently thinking’ about working down there. While being questioned by Mr Nicholson, Mr Chippindaie said the supervisor at McMurdo had told him previous Air New Zealand flights had gone below the stipulated 6000 ft minimum height. He said "quite by chance” he heard a tape-recorded radio communication between the crew of the November 21 Antarctic flight and McMurdo control.

It happened when crash investigators were listening to tapes covering the November 28 crash which had been “frozen” by the United States Navy after the accident. The reverse side of the tape bore an exchange be-

tween control and the November 21 Antarctic flight.

I The United States had i agreed to keep the tape in (safe custody. On hearing jthat, his Honour directed that the tape should be made available to the inquiry’.

Earlier during the hearing Mr Chippindale said there had been a considerable number of fatal aircraft crashes in Antarctica. He later produced figures which showed that in the post-war years until March, 1973, 30 fixed-wing aircraft and 20 helicopters had been involved in such accidents. Before the DCIO crash there had been only one aviation accident involving a non-military aircraft. It concerned a small twin-engine aircraft and occurred at the British base.