The limiting factor for aerial ops is daylight and the regs that CASA put out. As for the capability of the current fleet of aircraft, they do a great job. At the end of the day we as fire fighters put to much effort into knowing that we have that resource available and we not always get it. Just look at yesterday Malaga asked and 6AR said No. However saying that you read up on the research done by the Bushfire CRC in Canberra and they have proven time and time again that as soon as water bombing aircraft are in use the risk with the fire spreading dramaticly reduces greatly. (
http://www.bushfirecrc.com/)
(
http://www.bushfirecrc.com/research/a31/a31.html)
However in saying that the choppers don't fly out of the metro area, well there is a good reason for that. Out in the country there isn't to many water sources that you can draw from due to possible contamination of drinking water for humans and also stock. Also due to the vast distance that may require filling of the helicopters a fixed wing is better.
Remember that the AS350B3 that is ops as Helitac's only have 1000lts of water
PZL Dromader is 2500lts
Air Tractor 602 is 2500lts
Air Tractor 802 is 3200lts
From my Ground controllers book Helitac ops are 120km's from Perth Airport which gets your out east to Cunderdin, North to Wongan Hills and South to Harvey. Air Intel is 200km's with the fixed wing a lot longer than that.
The aircraft are based as follows
1x AT602 and 1 x 802 at Jandakot
4 x AS350B3's at Perth
1 x 802 and 1x 602 at Bunbury
2 x Dromaders at Albany
2 x Dromaders at Manjimup
Hey I would definitely think that a extra 2 AS350's would be great and I am sure the boys at HA would think so to (more work for them), and also an additional S61 (A S64 would be way better) would be good to. I am pretty certain that the S61 this year has a bambi bucket, so its going to be very interesting to see how that mixes in with the helitac's this year. The Carson was great as it was very accurate. Having worked with the S64 Skycrane/Aircrane, they are certainly a great machine, however I don't think that our state governments pockets are that deep at the moment.
As for the Skycrane/Aircrane the water tanks are 9000lts for the orange ones (Erickson Skycranes) and the red one that came out for a few years in Sydney based out of the Paramatta helipad was a Aircrane with 8500lts I think off memory.