Originally Posted by
vapilot2004
The repair ,had it been correctly accomplished should have lasted 10,000 cycles by Boeing estimates. According to records, the JAL 747 was already 2,000 cycles beyond that figure.
I *think* that the 10,000 cycle calculation took the improper repair into account and that a correctly repaired bulkhead would have lasted the natural life of the airframe. Also, if I remember correctly, once the bulkhead patches were in place it was difficult to see from the front that the splice only had one rivet line taking the strain and it wasn't until you saw it from the back that it became obvious. Amplifying the tragedy was that the Boeing engineer responsible for supervising the repair later took his own life, as did several JAL employees.
And yes, this was the first known incident where steering by thrust was attempted. Unfortunately the loss of the vertical stabiliser in this case (as opposed to UAL232 and DHL, where the empennage remained intact) made control practically impossible.
As for the original subject of the thread, I wonder if revisiting the aforementioned incidents in training, including that of ground crew would help sharpen focus on the seriousness of preflight checks?