In The Wake Of AAL 587, One Expert Calls Dependence On Them
"Naive"
As ANN reported earlier on Tuesday, Airbus
will recommend owners of its A300-600s and A310s inspect the rudder
assemblies of their aircraft in the wake of an incident more than a
week ago, where an Air Transat A310 lost its rudder in
flight. Now comes word that some American Airlines
pilots have demanded to be transferred off Airbus duty. And there
are nagging questions about those visual inspections: Are they
enough to ensure the aircraft's safety?
The Air Transat incident is eerily reminiscent of the American
Airlines Flight 587 mishap in November, 2001. As the nation reeled
from the 9/11 terror attacks, AAL 587, an Airbus 300-600, went down
near the New York shore, just moments after taking off from JFK on
a flight to the Dominican Republic. Terrorism was quickly ruled
out. Investigators quickly focused on the way the copilot
manipulated the rudder to avoid wake turbulence from a Boeing 747
not far ahead.
The NTSB later ruled the copilots abrupt rudder manipulations
probably caused the downing of Flight 587. Investigators also ruled
"design flaws" in the rudder actuation system aboard the A300 also
contributed to the accident.
Since then, some US pilots have started to view the A300 as an
anathema. The London Observer reports, since the crash of AAL 587,
approximately 20 American Airlines Airbus pilots have asked to be
transferred to Boeing aircraft. One pilot told the London paper he
was so convinced of a design flaw in the rudder system that he paid
extra money not to fly on an Airbus while vacationing.
"That is how convinced I am that there are significant problems
associated with these aircraft," he told the Guardian.
Are visual inspections adequate to the task of determining
whether potentially fatal problems exist in the rudder assembly of
A300-600s and A310s? Just after the AAL 587 mishap, MIT Professor
James Williams -- considered one of the leading experts in aviation
composites -- wrote a report in which he baldly stated the visual
inspection recommendations is "a lamentably naive policy. It is
analogous to assessing whether a woman has breast cancer by simply
looking at her family portrait." That report was also quoted by the
Observer.
Instead of a visual inspection or even a "tap" test to seek out
hollow areas within a composite structure, Williams and others in
the field say inspectors need to use ultrasound to actually get a
glimpse inside the tail structure. Williams said flight
after flight, climbing into sub-zero temperatures at altitude, the
composite material can fall victim to condensation. In turn, he
said, that would cause the carbon fibers inside the tail structure
to separate as water first freezes, then thaws. "Like a pothole in
a roadway in winter, over time these gaps may grow," he told the
London paper.
But Airbus doesn't buy that argument. Spokeswoman Barbara Crufts
calls Williams' theory "unproven," according to the Observer.
"You quote him as an expert. But there are more experts within the
manufacturers and the certification authorities who agree with
these procedures," she said. Crufts said the aircraft that suffered
the rudder separation over the Caribbean earlier this month had
been visually inspected just five days before the flight, although
she didn't know whether the inspection included a look at the
rudder assembly.