Paul Phelan/CAIRNS


Up to 5,000 Australian piston-powered general aviation aircraft - over half the national fleet - were grounded indefinitely in early January, pending resolution of a major fuel contamination crisis. The problem originated from Mobil Oil's refinery at Altona, Melbourne.

The safety measure affects all aircraft refuelled by Mobil or BP with 100/130 octane "green" avgas since mid-November anywhere on the highly populated eastern Australian coast and hinterland south of Townsville. New Zealand's general aviation aircraft fleet is being closely monitored. Major industry sectors in Australia are affected.

The Australian Bureau of Air Safety Investigation is examining possible fuel contamination in two recent helicopter autorotative landing accidents and at least three incidents involving light single-engined aeroplanes. In one, a student pilot lost power after take-off, but made a forced landing on the departure runway.

Civil Aviation Safety Authority (CASA) director Mick Toller describes the situation as "the worst case of fuel contamination I am aware of anywhere in the world". Toller has told the industry that it should be seeking compensation from Mobil.

CASA first grounded aircraft fuelled from the suspect source in late November, when a black residue was found in filters, carburettors and fuel injection systems after a change in refining processes.

The contamination took about a month to affect aircraft, but an airworthiness directive required inspections only of the systems, removal of foreign material, and draining and replenishment of tanks with uncontaminated fuel.

In early January, however, a second contaminant was discovered as a white gel-like substance in tanks.

Suspect aircraft were grounded again until CASA and Mobil devised workable field testing procedures and remedies. The Aircraft Owners and Pilots Association is urging members to consider legal action against the manufacturer, claiming it has evidence that the problem is older than Mobil admits.

Source: Flight International