Paul Phelan/CAIRNS

Australia's mainline air transport system was thrown into chaos in mid-April when the country's Civil Aviation Safety Authority (CASA) grounded 10 of Ansett Australia's 11 Boeing 767s over a maintenance error.

CASA director Mick Toller gave Ansett 10 days from 12 April to show why its operating certificate should not be cancelled.

Ansett has reacted angrily to the latest turn in events which began last December when an engineering paperwork error resulted in some of its 767s over-running an inspection requirement. Reviewing that incident, Ansett uncovered a further omission in which inspections of engine pylon attachments over-ran the times advised in a Boeing service bulletin. Ansett and Boeing agreed that those inspections should be completed by the end of this month, but four aircraft were voluntarily grounded by the carrier on 9 April when minor cracking was discovered.

Ansett operations chief Trevor Jensen says: "We've been working through that process. We don't agree with CASA's decision, we believe these aircraft are fully airworthy, and we will prove that."

Toller says Boeing and the US Federal Aviation Administration failed to recognise the problem's severity: "We will be asking both Boeing and the FAA whether the service bulletin that was put out was adequate in view of the fact that cracks were found on three aircraft."

Boeing responds: "We asked 767 operators to do an inspection [of engine pylon attachments] within 180 days [last year]. Boeing doesn't have the authority to make airlines conduct that test. CASA has the authority to go on its own and make recommendations." CASA has since issued an airworthiness directive. Ansett is conducting another internal investigation into its processes. The Australian Transport Safety Bureau says it will investigate whether CASA has been sufficiently "proactive".

Source: Flight International