To: Max Angle
The fact is that there are some failures on aeroplanes that are more often than not going to result in a fatal accident despite the best efforts of the crew. The certification process recognises that fact and should ensure that failures of that nature occur very infrequently.
What you have stated is correct but in this case it is only theory. That is how it is supposed to work but in this case it did not. The FAA, CAA and the DGCA were made aware of the problem but did nothing about it. When the runaway condition was first discovered there were 17 A-310 aircraft in service. The failure was an internal crack in one of the two hydraulic modules causing the slat iron bird to drive in the extended direction. The firm determined that the crack developed as a result of a faulty machining operation. The location of the crack did not allow direct visual or manipulative access to the damaged area. The firm manually tried to work out the area using sand paper and crocus cloth on 17 ship sets. They contacted the two operators (Lufthansa & Swissair) telling them that they had developed a more reliable power control unit and when they had a plane on the ground the firm would install a new pair of power control units at no charge. The contract required that any failure or incident during development that effected Reliability, Safety or Maintainability had to be reported to Airbus. No information regarding the failure was ever reported. Another design defect that was never reported to Airbus was the fact that the flaps and slats were not electrically bonded to the airframe. This was also reported to the FAA and the design was never changed. The internal crack developed at or about 1800 duty cycles and the in service aircraft were quickly approaching that number of duty cycles. Regarding the electrical bonding Airbus had a design directive that defined the design requirements to achieve electrical bonding and lightning protection. In that same directive were the procedures to be used to verify the electrical bonding and this would be performed on the production line by Airbus. Either the procedure was faulty or Airbus never performed the check because the lack of bonding was never discovered.
It has often been said that Line pilots are also test pilots.
To: Lungs
The information regarding this incident was never published nor, was it reported to the Canadian MOT. I found out about it when I was riding up front on a flight from Toronto to Chicago. I was discussing the problems above regarding a runaway system when the Co Pilot who was a four-striper and chief safety pilot handed me a fax. The fax stated that two days prior to that day an Air Canada A-320 experienced an uncommanded flap retraction on take off and the pilots had to use all available thrust to keep the aircraft flying until they built up air speed. It happened two days before Christmas in the year 2000 if memory serves me correctly.
