An in-depth audit of major US airlines' maintenance standards has found some defects which will lead to enforcement actions, but "lapses were not systemic in nature", says the US Federal Aviation Administration.

The audit was prompted by lapses uncovered during the Alaska Airlines accident inquiry.

Nick Lacey, director of the Flight Standards Service says the safety audits of American Airlines, America West Airlines, Continental Airlines, Delta Air Lines, Northwest Airlines, Southwest Airlines, Trans World Airlines, US Airways and United Airlines, were prompted by serious maintenance problems uncovered following the 31 January crash of an Alaska Airlines Boeing MD-83. The carrier came close to losing its authority to conduct heavy maintenance, but the FAA eventually accepted the airline's corrective action plan. Notable faults included unapproved maintenance techniques and repair deferral.

The FAA revealed plans to fine Alaska nearly $1 million for five maintenance infractions, including one that triggered the extraordinary audit. National Transportation Safety Board accident investigators have focused on maintenance of the MD-83's jackscrew assembly, which controls the horizontal stabiliser.

Lacey says AirTran is next on the audit list, which may extend to regional air carriers and all-cargo operators. Meanwhile, American, Delta, Northwest and United are subject to increased monitoring because of labour strife. Lacey says no safety issues have turned up so far. It is FAA policy to check for safety problems if a carrier is suffering labour unrest or financial stress.

Airline executives fear that consumer groups will use the audit results to produce a safety report card. Lacey says: "There is enough data, but it would not be reliable."

Source: Flight International