Improved Safety by Dribbles

Think about this: safety deficiencies have already been identified, but the Federal Aviation Administration (FAA) is dribbling out corrections in penny-packets. Not only does the practice put aircraft occupants at risk, it creates a nightmare for maintenance personnel.

Recall that after the fuel tank explosion that downed TWA flight 800 in 1996, the aviation industry was challenged to go back and look at its design practices for fuel systems and associated electrical components thereof, and come up with recommended fixes.

Since aircraft fuel systems already met the certification regulations, one would think there would be maybe a couple dozen items across all transport category aircraft that would need retroactive correction. Not so. Based on the FAA’s 2001 order, known as Special Federal Aviation Regulation (SFAR) 88, titled “Fuel Tank System Fault Tolerance Evaluation Requirements,” aircraft manufacturers were told to review their fuel system designs and recommend correction, by aircraft model, by component, to reduce the possibility of an ignition source igniting an explosion of fuel-air vapors.

Hundreds of potential safety hazards were identified. The FAA has been issuing airworthiness directives (ADs) ever since, ordering operators to correct problems. The most recent as the 1 October proposed AD addressing Airbus A330 and A340 passenger jets:

“Failure of the auxiliary power unit bleed leak detection system could result in overheat of the fuel tank located in the horizontal stabilizer and ignition of the fuel vapors in that tank, which could result in a fuel tank explosion and consequent loss of the airplane. The proposed AD would require actions that are intended to address the unsafe conditions …”

The FAA says this is one of 11 proposed ADs and 233 final ADs issued since the SFAR 88 design reviews were completed. They have been issued singly, or in small batches of three or four ADs. In addition, 26 additional fuel tank safety ADs have been issued addressing potential ignition sources discovered after the completion of the SFAR 88 reviews.

That’s 270 ADs all told. They’ve been published quietly from 2003 forward. How an airline maintenance operation is to keep track of and coordinate the necessary work is not the FAA’s problem. Meeting the varying compliance times, assuring parts and labor, is not the FAA’s concern. To the agency, issuance of the ADs “solves” the safety problem.

The total cost to the industry of the various fixes remains unknown. To appreciate the overall price in terms of labor, materials, aircraft down time, lost revenue, etc., would entail going through each and every AD.

Since the overwhelming majority of risks were identified through the SFAR 88 process, it would seem better, from a safety and scheduling standpoint, to issue as many ADs as possible at one time, together. Airline maintenance personnel would then see the scope of work involved and could incorporate the activity at the next overhaul period.

With more than 200 deficiencies corrected at one time, the safety of passengers and aircrews would be materially enhanced sooner.

Nor have the last of the ADs been published. The FAA expects to issue 40 more SFAR 88 related ADs. In other words, hazards already identified on airplanes carrying thousands of passengers a day. That’ a total of 310 fuel system safety corrective actions.

The last AD will be published in 2011. Why wait? If the deficiency is known, publish the AD now.

Thus, the ADs will have been promulgated over an eight year period, 2003-2011. The last AD will be issued some 15 years after TWA 800 blew up. Given the time allowed to correct each condition identified by AD, it will be at least 2016 before the final fixes are implemented.

If all corrections known in 2003 were implemented over the same five or six year deadline, safety would have been immeasurably increased by now, not by 2011 or by 2016.