Nick, the problem is that if it isn't signed off, nobody knows if it's been done or not.
Now if there is a page missing that contained the instruction that something had to be inspected and signed off, then nobody knows that nobody knows if it's been done or not.
I'm not being a smart@rse, that's the problem, and it's the problem that killed Ansett.
What CASA do is monitor the workings of the system, NOT the actual maintenance itself. An airline the size of QF is simply too big to actually monitor what gets done on a daily basis, it's simply not feasible. Instead they look at the Airlines maintenance system manuals, make sure there are no holes in them, then sample the actual work and documentation to see if the airline is actually in exact compliance with its own system....or not.
What the QF system is supposed to do is make sure (borrowing the old phrase) that Qantas know what they are supposed to know about their maintenance, or at least know what they don't know about it.
The killer is not knowing what you don't know - which is what the ATSB found at Ansett (although they didn't put it that bluntly). The B767 incident was the tip of the iceberg. Ansett had gutted it's maintenance planning function "to save money".' To avoid such a situation, you need plenty of mature aviation maintenance professionals with a little spare time on their hands, so that when an AD comes along, they have time to read, mark, learn, ponder and digest what Boeing or Airbus are prescribing, and ask questions if necessary, and you cannot rush this process.
If you do rush it, you eventually make mistakes, like the misinterpretation by a Japanese Professional Engineer of Boeing's rivetting instructions in a rear pressure bulkhead repair. The passengers had time to write farewell letters to their families before it eventually hit Mt. Fuji.
I'm sure there are no basic flaws at all in QF's maintenance system, but one wonders if the maintenance planning people generally have enough time to dig a little deeper into AD's etc. before time pressures force them to move on.
Last edited by Sunfish; 15th Aug 2008 at 19:18.