I will most likely get pilloried for this.
At the time the A-300 and the A-310 were certificated in Europe the certification documents were pure FAA with a DGCA cover on the manual. None of the certification requirements were JAR and there was no European content in the technical design requirements of the FARs. When the two aircraft were certificated in the United States the only thing the FAA did was to verify the two aircraft could fly on a standard commercial flight in the USA and they also tested the aircraft handling qualities. They did not question the technical aspects of the design they simply accepted everything put forward by Airbus and the DGCA.
For those of you that defend Airbus simply because it is on your side of the pond do not be so defensive. I can’t speak to the A-300 but I can on the A-310. Sometimes Airbus can not tell the certification authorities about a problem because they are not aware of the problem. When they do become aware of the problem they tell the certification authorities that the problem has been solved when it hasn’t. When Airbus is not aware of a problem it is the fault of their suppliers. Even though the supplier is mandated to inform Airbus of a problem they do not tell them because they would have to incur the cost of modification. They would rather Airbus discover the problem and write a scope change to the contract requiring modification and then the suppliers would get paid. The problem is not discovered by Airbus because they did not follow their own procedures. If they did the problem would have been discovered.
When the FAA is made aware of the problems they are like a mule as it takes a swift hit between the ears with a stick to get their attention. When the do take action they have two managers fired but the design is never changed.
One of the suppliers discovered a severe design defect on a hydraulic component that could cause runaway flap or slat movement. In stead of notifying Airbus the made a quick fix on 17 shipsets and contacted the two airlines flying the A 310 telling them that they had improved the design and would at no cost replace the two units on each aircraft.
The flap slat computer was inadequately tested and the flap slat computer reliability had never been assessed and the design defect alluded to above still exists on all of the aircraft.
The airlines are not guiltless. Air Canada suffered an uncommanded retraction of the flaps on an A 320 during takeoff and almost lost the airplane. The certification authorities were never notified and as a result other operators of the A 320 were not made aware of the problem
