The performance figures quoted by Piaggio are somewhat blunted by temperature considerations.
The one being trialled by westops manages about 350 TAS @ ISA +15 at around FL 320 - FL 350.
Given that the Kimberley and Pilbara (main operational areas) are regularly well above that (Summer, late Spring and Early Autumn ISA + 35 - 40), then you can knock quite a few more knots off that as well.
Not really a 390- 400 knot aeroplane unless being flown in winter below the
15th parrallel.
Apparently, once FL370 and above is reached there is an improvement in performance due to the drop in temps, however this is a bit of a moot point, cause if its around ISA+35, it will take forever to climb up there!
Given the constraints of the lack of a cargo door (current door only 600mm wide and poor Hot weather performance, I dont think this is the aircraft for this huge State.(particularly the northern half)
In order to significantly reduce sector times, and thus create a flow-on effect of reducing flight and duty times for crews, increasing aircraft and crew availability at the aircrafts home-base by not having the need for crews to overday or overnight at other bases a true 400 knot+ aircraft is needed.
Only a jet can fullfill this role and a small decrease in available working space in the cabin is not an insurmountable isssue.
In fact, since you can shave off around an hour and a quarter off a PD to JT sector, it would be most welcome by all.
As to the cost.............the figures need to be crunched by someone who knows more about accounting than I do, but from an operational perspective I think a Citation V would win out over the Pig in Western ops.
Hans