Saturday, March 25, 2006

One More Reason I Avoid Flying on Airbus Aircraft

Yesterday, the NTSB issued a letter (PDF file here) recommending inspection of all Airbus A-300 series aircraft, because during an investigation into a maintenance event where a FedEx Airbus was damaged, they also "found a substantial area of disbonding between the inner skin of the composite rudder surface and the honeycomb core".

This is alarming given what happened in a precursor ‘Air Transat’ event also described in the letter. Airbus had already responded to the earlier event by issuing ‘mandatory’ (non-regulatory, but required to maintain warranty compliance) inspection requirements to all Airbus operators. After this FedEx incident, Airbus issued more of this type of inspection requirements in the form of All Operator Telexes (AOTs).

Aircraft manufacturers and regulatory agencies work very hard to keep air transportation safe, and these kind of actions that require operators to look at their fleets are quite common. What distresses me in this case is the NTSB’s unhappiness with certain aspects of Airbus’ course of action (bold emphasis mine).
Although the Safety Board concurs with the procedures outlined in AOTs A300-55A6042, A310-55A2043, A330-55A3036, and A340-55A403 dated March 2, 2006, it is concerned that allowing an undetected hydraulic-fluid-induced disbond to exist for 500 flights, without supporting analysis or tests to better understand the safety risks, is unacceptable.
The NTSB thus recommends to the FAA that they:
Require that all operators of Airbus A-300 series airplanes immediately comply, with Airbus All Operators Telexes (AOT) A300-55A6042, A310-55A2043, A330-55A3036, and A340-55A403 dated March 2, 2006. Any disbonding to the rudder skins that occurs in the presence of hydraulic fluid contamination should be repaired or the rudder should be replaced as soon as possible, well before the 2,500 flights specified in the AOTs. (A-06-27) Urgent[.]

Establish a repetitive inspection interval for Airbus premodification 8827 rudders until a terminating action is developed. The interval should be well below 2,500 flights. (A-06-28).
If this was an isolated problem, I wouldn’t be too concerned. However, Airbus' attitudes towards their history of composites failures (the ill-fated American Airlines Flight 587 is referenced anecdotally in the NTSB letter, and IMHO there are still unanswered design questions related to the vertical stabilizer shearing off), and Airbus’ PR machine minimizing the importance of last month’s load test failure of their new jumbo A380 wing, speaks volumes about their design, manufacture, and business culture.
The possibility that Airbus might not have what I would call the 'proper' commercial aircraft design culture first popped up on my radar in 1988 when, during an air show, a software vs. test pilot conflict turned an airliner into an enormous hedge clipper. There were a lot of irregularities surrounding the event including powerful evidence that cockpit recorders were tampered with by Airbus, possibly with direct government support. Events since then have only reinforced my opinion that Airbus does not have a mature commercial aviation culture that can reliably design, much less produce the kind of airplanes I want to fly in.
Bottom Line: Composites are a relatively new (compared to sheetmetal) technology that is still evolving rapidly: they require extra caution in determining safety, NOT less. And I want a Human Brain Release 1.0, with a Mark 1 Mod 0 eyeball making the final decisions in the cockpit, because that person has the same stake in the outcome as I do as a passenger. Let computers assist, not argue with the pilot.

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