WASHINGTON, Oct 4: Nine US airlines outsourced more than 70 per cent of their major aircraft maintenance last year, according to a government report.

One-fourth of the outsourced maintenance is being handled by contractors overseas.

The Transportation Department’s inspector general said the outsourcing, which has more than doubled in four years, was of concern because the Federal Aviation Administration has failed to closely track how much maintenance is farmed out and where it is performed.

In their effort to lower costs, the report said, airlines continue to shift their heavy airframe maintenance from their own in-house mechanics and engineers to hundreds of repair companies in the United States, Canada, Mexico and countries in Central America and Asia.

Nine major airlines examined by the inspector general outsourced 71 per cent of their heavy air frame maintenance _ repairs and servicing to an aircraft’s body, wings and tail _ in 2007, up from 34 per cent in 2003.

More than a quarter of that maintenance -- 27 per cent -- was performed at foreign repair facilities.

The airlines examined in the report were AirTran Airways, Alaska Airlines, America West Airlines, Continental Airlines, Delta Air Lines, JetBlue Airways, Northwest Airlines, Southwest Airlines, and United Airlines. American Airlines, the nation’s largest domestic carrier, was not included, the inspector general said, because it handles most maintenance in-house.

FAA requires each repair station to undergo a government inspection at least once a year, FAA spokesman Les Dorr said. The report says those inspections often are not being conducted by agency inspectors most familiar with standards and requirements of the airline whose planes are being repaired.

One safety expert, however, said the report underscores that FAA still has a long way to go toward resolving the outsourcing issue, which has been source of controversy for the agency for several years.—AP