The Tuskar air disaster in 1968 was probably caused by structural failure in the plane's tailfin, a new study has found.In a report which casts further doubt over the findings of the original investigation, an independent team of air crash experts dismissed theories that the Aer Lingus plane was hit by an unmanned drone or missile.
But the team said it could not offer a definitive explanation for the crash that killed 61 people when the Viscount aircraft plunged into the sea near Tuskar Rock on March 24th, 1968. Only 13 bodies were recovered. The plane, named St Phelim, was travelling to London from Cork.
The investigators, from France and Australia, said the accident was probably caused by an "initial event", which they were unable to identify, leading to structural failure of the port tailfin.
"There was a strong indication that structural fatigue, flutter, corrosion or bird strike could have been involved," they said. "The manoeuvres of the aircraft following the initial upset and the subsequent flight would have been outside the airworthiness certification envelope and may have resulted in some deformation of the structure."
As control was progressively lost, the plane remained airborne at low altitudes for more than 30 minutes after the "event". Out of radio range, the pilot struggled to save the plane.
Said the report: "It was a major achievement for the crew to be able to keep this aircraft flying for more than half an hour, with such poor manoeuvrability characteristics. This showed a remarkable intrinsic and professional level of experience."
The investigation by Mr Colin Torkington, Mr Yves le Mercier and Mr Manuel Pech, was the third carried out on the accident. Unlike the original investigation, they used data from all other incidents and accidents involving Viscount planes worldwide. The circumstances of a crash in Indonesia in 1972 were deemed particularly relevant in the latest attempts to understand what happened.
The findings were welcomed by the Minister for Public Enterprise, Ms O'Rourke, who said she was "very struck" by deficiencies identified in the report of the 1968 investigation.
The original report, by the late Mr Richard O'Sullivan, was the first to raise the possibility of involvement by a British missile or drone. But the new investigators said they were convinced this could be ruled out.
They said: "We have carefully examined all aspects of the tests conducted in the UK ranges and of the sea and air activities performed on that Sunday. It is our opinion that all theories involving the presence of another aircraft can be rejected."
The new study was initiated in 2000 after a review of files carried out by the Air Accident Investigation Unit at the Department of Public Enterprise. That review noted that Mr O'Sullivan's investigation failed to state that maintenance records from the penultimate check on the St Phelim were missing.
But while these findings were accepted by the new investigation team, it said there was "no evidence" to suggest that omissions on the penultimate check in December 1967 contributed to the disaster. The investigators noted: "Serious errors in Aer Lingus maintenance scheduling may be indicative of a less than ideal work culture existing in the airline at that time."
Still the investigators found further flaws in the 1968 investigation. They said "insufficent effort was made to thoroughly reconstruct the track of the aircraft" and said "pertinent material was excluded".
Stating that accounts of the plane's movements offered by about 46 witnesses were dismissed by the original investigation, the new report found the evidence of witnesses could be considered to be factual "since all the statements fit one to the other".
Text of summary of accident report with links to report's full text
[ http://www.ireland.com/newspaper/special/2002/tuskar/index.htm ]
