Says DOT Ignored Union's Call For Even Tougher Standards
FAA Aircraft Certification
Engineers, represented by the National Air Traffic Controllers
Association (NATCA), say they're pleased which much of
the DOT's announcement Wednesday of a final rule requiring
fire suppression technology to be installed in the
center fuel tanks of airliners flying over the US.
The union notes that by issuing the ruling, the FAA retained the
retrofit requirement for passenger airplanes, and modified the
final rule to apply the same fuel tank flammability standards to
all new transport category airplane designs. But while engineers
are pleased those requests were maintained, they're disappointed
the FAA "missed an opportunity to greatly enhance airplane safety,
without significant additional cost."
NATCA says the FAA rule allows the flammability of fuel tanks
located in the wings to be higher than fuel tanks located within
the fuselage contour -- not accepting the changes requested by both
NATCA and the National Transportation Safety Board to apply the
more stringent flammability standards to all fuel tanks, not simply
the center tanks.
"If another TWA 800 type of accident is to be avoided, it is
necessary to require that all fuel tanks meet both the ignition
prevention requirements adopted by the FAA in 2001 and the most
stringent of these new fuel tank flammability reduction
requirements recommended by NATCA," the union states.
Specifically, the new rule does not require wing tank standards
to meet the same warm-day requirement applied to fuel tanks located
inside the fuselage. As discussed in the letter from the NTSB to
the FAA administrator in 2006, the Transmile Airlines B-727
airplane (aluminum) wing tank explosion in Bangalore, India (on May
4, 2006) demonstrated the flammability exposure of aluminum wing
tanks is not low enough to prevent fuel tank explosions.
The union strongly believes that applying the same warm-day
requirement to wing tanks is important considering many new
airplane designs, like the Boeing 787 and Airbus A350 XWB, will use
wings made from composite materials instead of the traditional
aluminum construction. NATCA notes Boeing plans to provide just
such a fuel tank flammability reduction system on the 787, though
it's not required to do so under the new rule.
Composite wing tanks will not cool as quickly as wing tanks made
from aluminum and this will cause composite wing tanks to be more
flammable than aluminum wing tanks, especially on warm days.
Composites are also generally less electrically conductive than
aluminum, which can make it more difficult to protect against
ignition sources due to lightning, electrical shorts and