US safety regulators are seeking up to $162.4 million in fines against American Airlines and its affiliates for alleged violations of safety standards going back several years.

Those sanctions that would dwarf any previous penalties against an airline.

Many of the investigations had not been disclosed until the Federal Aviation Administration filed documents describing them to the federal court handling the bankruptcy case of American Airlines and parent AMR Corp.

The documents underscore the scope of the FAA’s concern about the maintenance program at American Airlines, the nation’s third-largest airline. They come to light just as American Airlines tries to fix labour and financial problems and turn itself around.

American Air said today that it has been working with federal officials for several years to improve training and oversight in its maintenance operations.

“Safety is fundamental to the success of American Airlines, and at no time did American operate an aircraft that was unsafe for flight,” said AMR spokesman Michael Trevino.

AMR will try to reduce any penalties through negotiations, Trevino said. That’s a standard approach when the FAA proposes fines against an airline for alleged violations of federal safety rules.

The FAA filed its claim in US bankruptcy court in New York just before a July 16 deadline, but the move went unnoticed for weeks.

It was first reported by The Wall Street Journal.

The FAA said in a statement that it filed the claim to make sure that the government gets paid just like other creditors in the AMR bankruptcy case. It declined further comment, citing ongoing investigations. In some cases, the agency had not yet formally notified American of the proposed fines.

The largest single fine spelled out in court documents is $39.3 million against American for allegedly failing to fix wiring work on its Boeing 757 aircraft in 2009.

Federal specifications are designed to prevent electrical arcing and fires. The FAA said that before the jets were inspected and repaired, American Air used 113 of them to make 1,480 flights carrying passengers.

American Air already held the record for the largest proposed penalty against any airline $24.2 million, which the FAA announced in 2010 for allegedly improper repairs of wiring around the landing gear of American Air’s MD-80 aircraft.

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