On the day that SIEVX sunk (19 October) it appears that two unusual things occurred in regard to aerial surveillance in the Charlie sector:
1 - a second P3 flight was substituted for the routine Arunta helicopter flight
2 - the second flight was cut short and failed to search in the crucial north-west sector due to bad weather.
During the life of Operation Relex on how many occasions was Arunta's helicopter unavailable and a second P3 flight scheduled in its place?
During the life of Operation Relex on how many occasions was the usual surveillance pattern cut short by bad weather in Charlie sector?
During a peak surveillance time, such as 18-22 October last year, when there are reports of multiple SIEVs departing Indonesia, when an Orion made an 'unidentified radar contact' did it also observe and make note of the direction in which the vessel was heading?
When an Orion made an 'unidentified radar contact' close to the border of the aerial surveillance zone (such as the contact at 0919 on 19 October) did it sometimes make follow up observations about such a vessel?
When an unidentifed radar contact close to the northern border of the Charlie sector surveillance zone appeared to be heading south - would it ever happen that that vessel would be identified?
When an Orion made an unidentified radar contact within the perimeter of the aerial surveillance zone and there were no other vessels observed in the immediate vicinity (such as the contact at 1930 on the 2nd flight of 19 October) how often would it fail to identify that vessel?