FlyAAway

From AMRCorp website (under Fleet Statistics):

American Airlines Aircraft Maintenance Procedures

American Airlines is proud of its maintenance record, procedures and employees. The airline
performs 11 man-hours of maintenance for every one hour of flight time on its aircraft. The time
frame for maintenance procedures is based on a combination of the number of hours the aircraft
flies, the number of take-offs and landings (referred to as "cycles") it makes, plus the age of the
aircraft. Here is a brief explanation of American’s maintenance check procedures:

"PS" Daily Checks

Every aircraft is checked every day in its "PS" (Periodic Service) check. The aircraft is visually
inspected and its maintenance log book is checked for entries and maintenance needs. The "PS"
check can be performed overnight or during downtime during the flight day. It averages
approximately two man-hours.

"A" Checks

The "A" check is more detailed than the "PS" check. "A" checks are performed roughly once a
week (approximately 60 flight hours). The "A" check is performed at one of 40 stations around
American’s system. It averages 10 - 20 man-hours.

"B" Checks

The "B" check is an even more thorough maintenance check. The "B" check is done
approximately once a month (roughly 300 - 500 flight hours). Besides specific service performed on
the aircraft, a detailed series of systems and operational checks are performed. American always
performs "B" checks inside one of its hangars at seven different cities around its system. A "B"
check requires approximately 100 man-hours on narrowbody aircraft (those with only one aisle)
and approximately 200 - 300 man-hours on widebody aircraft (those with two aisles).

"C" Checks

The "C" check is the most thorough type of maintenance work performed by American. The
airframe — virtually the entire aircraft — goes through an exhaustive series of checks, inspections
and overhaul work. It is performed at either of American’s heavy maintenance and engineering
centers in

Tulsa, Oklahoma or the Alliance Maintenance Facility in Fort Worth, Texas. There are different
levels of "C" checks depending on the type of aircraft. These include:

Narrowbody "C" Checks

American does two types of "C" checks on its narrowbody planes. The first is a "Light C" check,
which occurs approximately once a year. It requires approximately 2,100 man-hours and three
days to accomplish. Every fourth "Light C" check becomes a "Heavy C" check. This check
requires 20,000 - 30,000 man-hours and takes from three to five weeks to accomplish.

Widebody "C" Checks

Because of the complexity of widebody aircraft, all "C" checks are "Heavy C" checks. The
complete airframe inspection and service is done every 15 - 18 months. It takes approximately
10,000 man-hours and from two to four weeks to accomplish a widebody "C" check.

Jet Engine Overhauls

Modern jet engines are among the most reliable devices in aviation. American does not replace
and overhaul jet engines at a specific number of hours. Instead, American uses a 24-hour-a-day
"condition monitoring" process that scientifically tracks the condition of every engine on every
aircraft. Besides visual inspection, technicians monitor the internal condition of every engine, using
such procedures as boroscope inspections and oil sample spectographs. The goal is to replace
and overhaul an engine before a problem can occur. Engine overhauls are performed at the Tulsa
and Alliance-Fort Worth Maintenance and Engineering facilities. The engine replacement is usually
performed at one of the six "B" check hangar locations around the country