The Federal Aviation Administration has proposed a $24.2 million civil penalty against American Airlines for failing to follow correctly a 2006 airworthiness directive involving...

The Federal Aviation Administration (FAA) has proposed a $24.2 million civil penalty against American Airlines for failing to follow correctly a 2006 airworthiness directive involving the maintenance of its McDonnell Douglas MD-80s.

This civil penalty is the largest ever proposed by the FAA. It concerns FAA inspections in the spring of 2008 which led to American Airlines grounding its fleet of more than 300 MD-80s temporarily in April 2008 in order to complete the actions required by the airworthiness directive. The grounding caused massive disruptions to American’s domestic route network for several days.

“We put rules and regulations in place to keep the flying public safe,” says U.S. Transportation Secretary Ray LaHood. “We expect operators to perform inspections and conduct regular and required maintenance in order to prevent safety issues. There can be no compromises when it comes to safety.”

American Airlines is gradually retiuring its huge fleet of McDonnell Douglas MD-80 jets, which at one time numbered around 365 aircraft. The airline has donated one to George T. Baker Aviation School near Miami International Airport, the aircraft being transported by crane and road from the airport to school in the small hours of May 20, 2010

The FAA alleges American did not follow steps outlined in a 2006 airworthiness directive requiring operators to inspect wire bundles located in the wheel wells of MD-80 aircraft. The Airworthiness Directive (AD), AD 2006-15-15, required a one-time general visual inspection by March 5, 2008 for chafing or signs of arcing of the wire bundle for the auxiliary hydraulic pump. The AD also required operators to perform corrective actions in accordance with the instructions of the applicable Boeing service bulletin.

A service bulletin is a document issued by an aircraft manufacturer to operators of a specific aircraft type or types recommending specific maintenance actions or inspections on their aircraft when potential safety issues come to light. Although not having the force of official airworthiness directives, service bulletins are often released by manufacturers in advance of the regulatory authority or authorities concerned issuing ADs on the matter, and aircraft operators usually take them seriously.

In the case of AD 2006-15-15, the purpose of the FAA’s airworthiness directive was to prevent the shorting of wires or arcing at the auxiliary hydraulic pump, which the agency said could result in loss of auxiliary hydraulic power or a fire in the wheel well of the aircraft. The airworthiness directive also sought to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination with the flammable vapors inside the fuel tanks, could have resulted in a fuel tank explosion.

The FAA first detected the violations on March 25, 2008, during an inspection of two aircraft. The FAA informed American’s management that the aircraft did not comply with the AD, prompting a series of re-inspections and additional maintenance work that occurred during the following two weeks.

On March 26, 2008, after American performed additional maintenance on its huge fleet of MD-80s, the FAA inspected eight aircraft at American’s Tulsa maintenance base and found that seven did not comply with the airworthiness directive. On April 7, the FAA inspected another nine American Airlines MD-80s at Dallas/Fort Worth International Airport and found that eight of them still did not comply with the AD.

A tenth aircraft inspected by American’s mechanics also did not comply. On April 8, 2008, American began grounding its MD-80 fleet to conduct new inspections and redo work as necessary. The groundings resulted in widespread delays across American’s domestic route network during the following several days.

The FAA subsequently determined that 286 of the airline’s MD-80s were operated on a combined 14,278 passenger flights while the aircraft were not in compliance with U.S. federal regulations. American did ultimately complete the work required by the 2006 Airworthiness Directive, the FAA says.

Over the past year and a half, FAA safety officials have reported progress in working with American Airlines to help improve the airline’s maintenance culture, according to the agency. The FAA says it is committed to continuing that work.

American has 30 days from the receipt of the FAA’s civil penalty letter to respond to the agency.