Inaccurate fuel gauges puzzle American officials
By TREBOR BANSTETTER
STAR-TELEGRAM STAFF WRITERS
FORT WORTH - American Airlines is checking the fuel systems of 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 tiny 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 also is managing director of flight
operations. "We still don't know for sure."
American officials insist that their airplanes remain safe, and point out
that all flight 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 "round the clock" on the issue.
It also demonstrates the increasing challenges American faces maintaining
its airplanes as its fleet ages. The airline has deferred or cancelled many
aircraft purchases in recent years to save money, and plans to buy only two
new airplanes before 2013.
"There's always a tradeoff," said Alan Sbarra, an aviation consultant with
Roach and Sbarra Airline Consulting in San Francisco. "You save money when
you don't buy new aircraft, but then you spend a lot more time and money on
maintenance as they get older."
Dillman said the problem has also surfaced at other airlines that operated
MD-80s. "This is an industry issue," he said.
American officials declined to say how much the fuel gauge issue has cost
the airline. Last year, American spent $228 million on maintenance,
materials and repairs.
Unlike most carriers, American still services its aircraft in-house, rather
than outsourcing the job to contractors. The carrier has maintenance bases
in Fort Worth, Tulsa, and Kansas City, Mo.
That's an advantage when it comes to issues such as the fuel problem,
Dillman said.
"We've maintained the MD-80 for years in-house," he said. "At this point, I
think we know more about this aircraft than Boeing does."
American operates the world's largest fleet of MD-80s, with 337 in service.
The aircraft is used heavily at Dallas/Fort Worth Airport.
When it comes to the mysterious microbes in the fuel tanks, one theory is
that the growth of the tiny pests was spurred by excess seawater that was
blown into the jet fuel supply during Hurricane Katrina, Dillman said.
Others say the MD-80 is particularly susceptible to the problem because it
doesn't burn off water in the fuel tanks as well as other aircraft. And one
airline report says a polyurethane coating on the fuel tank probes in some
older airplanes may have lost its effectiveness.
Regardless, American officials have moved aggressively in recent weeks to
investigate the problem and ensure that no flight ends up short on fuel.
This month, mechanics manually inspected every fuel tank on each of
American's MD-80s to make sure none were giving critically inaccurate
readings. They have also beefed up maintenance procedures to focus more
intently on the fuel systems.
Mechanics at American's maintenance base in Tulsa "have been working around
the clock to find a solution to this dilemma," stated a recent message to
pilots from David Johnson, the airline's MD-80 fleet captain.
The work includes:
A one-time, manual check of the fuel level in the tanks of every MD-80 in
the fleet.
More frequent draining of water out of the airplanes' fuel tanks.
Adding a chemical that slows down the growth of the microbes.
Increased inspection of the fuel systems during regular maintenance checks.
Paper fuel reports are given to pilots before every flight so they can
double-check the gauges.
American has also sent a team of workers to inspect fuel stations on the
East Coast that are supplied by Gulf Coast refineries, to test the hurricane
theory, Dillman said.
Airline officials stress that even with the inaccurate readings, no
airplanes have been in danger of running out of fuel during a flight.
Airplanes typically take off with several thousand pounds of extra fuel.
"There is an extremely large cushion of safety out there," said John Hotard,
a spokesman. He added that American's maintenance department spotted the
trends early on and has aggressively worked to solve the problem before it
could become a larger issue.
Still, inaccurate fuel gauge readings are a serious matter for an industry
where safety is crucial. Last summer, an incorrect fuel reading caused an
engine on an MD-80 to flame out as it approached Chicago.
The plane landed safely with the remaining engine. Mechanics later
determined that the problem in that case was due to a mechanical breakdown
in the fuel system rather than microbe growth in the tank, Dillman said.
According to one internal report obtained by the Star-Telegram, American
found 50 instances last year when fuel gauges gave inaccurate readings.
Of those 50, the report stated, 10 were off by 500 or more pounds of fuel.
"We must have complete assurance that our fuel quantity gauges are
accurate," the report stated. "Reasonable assurance is never good enough in
the flying business."
Dillman said that while any fuel gauge error is considered serious, it
should be taken in context with the total number of flights operated by
MD-80s.
"Certainly it's significant, but keep in mind we flew 460,000 flights last
year," he said.
The airline has also been communicating regularly with pilots and has
advised them that the airplane is safe to fly. But officials have also
warned that pilots need to remain vigilant and aware of potential problems.
"You are a proud bunch of aviators flying a proud bird," wrote Johnson in
his message to pilots. "I'm glad we are keeping it pointed in the right
direction together."
Trebor Banstetter, (817) 390-7064
[email protected]