Originally Posted by
werbil
I haven't read the report to see how many sectors the pilot had flown that day. CO binds extremely extremely well to haemoglobin preventing the transfer of oxygen. Once it's in your bloodstream it takes ages to wash out.
According to the interim report, that day
... the pilot had conducted seven flights in VH-NOO. This included two short scenic flights over Sydney Harbour, four flights to/from Cottage Point, and one positioning flight without passengers from Cottage Point to Rose Bay. The accident flight was a return flight to Rose Bay.
The accident flight taxied away from Cottage Point around 1505 and was airborne around 1512, so a 6-7 minute taxi.
The photograph of the
engine exhaust collector-ring showed a pre‑accident crack that had been further propagated by the crash. There was sufficient discolouration around the crack to suggest that exhaust gases had been escaping for some time.
Interestingly the report says blood tests showed 'the pilot and two of the passengers had elevated levels of CO'. The pilot I could understand; the two passengers strikes me as odd. Forensically the first question you'd want resolved is were any of them smokers; given the details recounted about the pilot it's unlikely he was.
Other pilots must have been flying NOO. I'd be interested to hear if anyone was complaining about headaches. CO poisoning is not entirely innocuous - a dull but persistent headache is a very commonly experienced early symptom.