The Bern Report

The Swiss Aircraft Accident Investigation Bureau published its final report into the helicopter crash near the Theodul Glacier, seventeen months after the accident that killed Gregory and Philippa Lahey, the pilot Urs Brunner, and four German tourists. The report was issued from the Bureau's offices in Bern and circulated to the families of the dead through their respective embassies.

The investigators found that the crash had been caused by a fatigue fracture in the tail rotor drive shaft. The crack had begun at a microscopic flaw introduced during manufacture and had grown over several hundred flying hours. It had not been detectable by the inspection methods the operator was required to use, and the operator's maintenance records were found to be complete and in order. When the shaft failed, the pilot lost directional control. The report concluded that the deteriorating weather had removed any realistic chance of a controlled landing, and that the outcome would probably have been the same for any pilot.

The report made three recommendations. One was a change to the inspection regime for the drive shaft component, which the manufacturer adopted later that year. The others concerned operating limits for sightseeing flights in marginal alpine weather. The report did not mention, and the investigators had no reason to consider, any of the rumours that had circulated in Tasmania about the couple's journey.

An English translation reached 19 Hobart Road through the Australian Embassy the following month. Patrick Lahey read it through twice at the kitchen table, then read the technical appendices, and then put it away in a drawer in his workshop. Jane Lahey declined to read it, and asked him not to tell her what it said. He told the children only that nobody had done anything wrong. Oscar, nearly fourteen, found the report in the workshop drawer some months later and read it himself without telling anyone.