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 electrostatics.

FMI: Read The Final Rule, www.natca.org