2006-05-05 / Editorial/Opinion

From the Editor's Desk

By Howard Schwach


I was going to continue my series about school problems this week, but something more compelling came up and that will have to wait until next week.

What happened was Transportation Safety Board of Canada (TSB), that nation's equivalent of our NTSB, had the guts to say what our agency has been afraid to say since November 2001.

What it said, basically is that Airbus Industries has a real problem with the way it builds its A300 series aircraft because the aircraft in that series have a propensity to lose their tail fins and rudders in the air, whether they are under load or not.

The Canadian agency's report, issued on March 27, does not mention the crash of American Airlines Flight 587 in Rockaway in 2001 even though the plane that crashed was an Airbus A300-600. Yet, it has everything to do with that crash.

Rather, it deals with the "upset" of Air Transat Flight 961. On March 6, 2005, that flight, an Airbus A310-300 (with the same tail material and configuration as the A300) departed from Juan Gomez International Airport in Cuba bound for Quebec.

According to the TSB report, the aircraft was at 35,000 feet and experiencing no turbulence when the crew heard a loud bang that was followed by vibrations that lasted for a few seconds. The aircraft then entered a repetitive rolling motion, known in aircraft parlance as a "Dutch Roll." The pilots managed to get the aircraft to 19,000 feet when the aircraft came under control.

The plane turned around and went back to Cuba where it was discovered that the aircraft's rudder was missing.

Our NTSB has gone to great pains to explain that the Air Transat upset was nothing like American 587 because, in the former only the rudder fell off where, in the latter, the entire tail structure came off.

I don't really see the difference, except perhaps in the extent of the damage.

The Canadian report says, "The rudder is made of composite sandwich construction, consisting of a nomex honeycomb cord with carbon fibre face sheets. It had separated from the aircraft except for its bottom closing rib and the length of the spar between the rib and the hydraulic actuators. An examination of the vertical tail fin of the aircraft, to which the rudder is attached, determined that the two rearmost fin attachment lugs were delaminated, likely the result of stresses that existed during the rudder separation."

Anybody who has seen the lugs that attached the tail fin to the fuselage of the A300 that was AA 587 will understand that the TSB might well be talking about that aircraft as well as Air Transat Flight 961.

You have to follow the bouncing ball a little to understand how this all comes together because there is no direct timeline to follow.

The AA 587 crash occurred on November 12, 2001. The Air Transat upset took place on March 6 2005. There were a number of earlier 'upsets" with A 300 series aircraft as well prior to AA 587, but they are not germane to the story I am telling in this slot.

What ties them together is an event that happened on November 27, 2005, four years after AA 587 and nearly 10 months after Air Transat.

On that day, mechanics were working on a Federal Express (FedEx) Airbus A300-600, doing some repair work on the rudder systems.

The mechanics found that there was some delamination of the material making up the lower left panel in the rudder. What that means is that the separate layers that make up the laminate were coming apart.

When our NTSB examined the problem, it determined that the initial delamination was the result of hydraulic fluid leaking onto the laminate. The problem, it seems, impact about 370 aircraft, including all of the A300-600, A310, A330 and A340 aircraft.

That means all of the A300 series aircraft used by American Airlines, the only American carrier that used those aircraft for passenger routes.

Tests on the rudder in a depressurization chamber resulted in "significant further growth in the damage" to the lamination, the report says.

"Although a direct correlation between the Air Transat and the FedEx event cannot be positively linked at this time, the event confirms that significant delamination of these rudders can progress unnoticed, in spite of the present maintenance standards in place."

Then, the Canadian report adds something that is important to everybody concerned with the real cause of the AA 587 crash.

"The recent discovery that disbands can grow undetected and the increasing age of the composite rudders suggest that increased attention is warranted to mitigate the risk of additional structural failures.

The consequences of a rudder separation include reduced directional control and possible separation of the vertical tail plane (emphasis added)."

Everybody has seen the photographs of NYPD launches, Coast Guard Cutters and DEP dredges all pulling pieces of AA 587's tail structure from Jamaica Bay after the crash.

The tail was in more than a dozen pieces when it was retrieved and the NTSB assumed that it fell apart when it hit the water.

It is more than possible, however, that the plan's disbanded rudder fell away, putting forces on the tail fin that pulled it apart before it departed the plane.

The TSB report proves that it is possible, as does the Air Transat upset and the FedEx event.

The NTSB, however, continues to say that the more recent problems had nothing to do with the AA 587 crash, that the first officer used the rudder too aggressively, ripping the tail structure off the plane in one piece. Then, when it hit the water, it broke into more than a dozen smaller pieces.

Do you believe the NTSB conclusion, especially in light of the more recent evidence? If so, I have a bridge you might like to buy.

What seems to me to be more likely is that the rudder and attachment lugs in the A300 were badly disbanded. As the plane gained altitude, the rudder began to break into pieces and fall from the plane. That, in turn, caused pressure on the tail fin that caused it to be ripped from the plane as well.

That theory is not mine alone. A recent letter from three American Airline pilots and two AA first officers posits the same thing and asks the NTSB to reopen the investigation.

"The [NTSB] safety recommendation has released significant data that throws a new light on some of the presumptions made in the AA 587 investigation," the letter says.

It is time for the NTSB to see the light, forget political correctness and reopen the probe into the reasons for the accident. It will probably not do so, because both the FAA and the NTSB are more concerned with protecting the airlines and aircraft industry than they are concerned with aircraft safety.

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