FORT WORTH - American Airlines is checking the fuel systems in its entire fleet of Boeing MD-80 aircraft, after a mysterious spate of incidents in which cockpit gauges showed the wrong amount of fuel on board.
The source of the problem remains a puzzle, airline officials say. It appears to stem from an increase in microbes growing in fuel tanks. Those particles can affect the probes that tell pilots how much fuel is on board.
"Everybody has their theory about why this is coming up right now," said Don Dillman, an American pilot who is also managing director of flight operations. "We still don't know for sure."
American officials say that their airplanes remain safe, pointing out that all flights carry a fuel reserve far in excess of the reported discrepancies. Still, the problem has been a major headache for the airline's maintenance department, which, according to one internal report, has been working "around the clock" on the issue.
It also demonstrates the increasing challenges American faces in maintaining its fleet of airplanes as it ages. The airline has deferred or canceled many aircraft purchases in recent years to save money, and plans to buy only two new airplanes before 2013.
