Originally Posted by
havick
You’re forgetting right tool for the right job. you don’t use a ball peen hammer when a sledge hammer is needed.
i used to wonder about VLATS until one day I was bombing in a Bell 412 and was working side by side with a Coulson C130 near ballarat. It was amazing to see the effectiveness for that particular strategy that day on that particular fire and I can categorically say that that particular fire would have gone on for at least another 2-3 weeks of it weren’t for the VLAT and small machines mopping up and directing it to the VLAT lines.
And
that is what I am saying - a maximum of 1200 tonnes proven from the Canadair (under ideal conditions that almost never exist) but based on North American figures 36 tonnes per hour average versus 15 tonnes every two hours from the 737 means the Canadair is the sledge hammer with 4.8 times the 737s delivery on average in NA. Using a fleet like many European countries do they can lay down more than 15 tonnes per minute - that is a massive sledge hammer being some 120 times more than the 737 making it a plastic toy ball peen.
And I am not saying VLATs or helicopters or cropdusters do not have a place on the fire front. The VLAT are excellent for creating a chemical fire break ahead of the fire but it is tonnes per hour delivery that wins the day in Europe and VLATs cannot provide anywhere near what the Canadair does. At the other end of the scale helicopters and cropdusters can go even lower over small areas and dowse them more efficiently than larger aircraft.
The C-130 may be able to go as low as the Canadair but the only jet that can is the Bae146/RJ85, which can extend the speed brakes so that it can carry almost takeoff power while flying slowly. All other jets have long spool up times to contend with so must fly higher which results in wider dispersal of the drop -- roughly four times as much if you just double the altitude. Wider dispersal reduces the battering ram effect that the lower drops can achieve. That in turn knocks over hollow trees that if left standing keep spewing hot embers which cause relights and spotfires.
Obviously if the airport has a system that allows rapid reloading and the fire is very close the VLAT may catch up to, or even exceed, the Canadair in tonnes dropped but how many airports in Aus have the ability to load at the maximum rate the aircraft can accept?
Have a look at this years fire zones and the various dams like the Hume weir, Eildon, Thompson and other dams, plus those areas mother nature provides and with relatively long distances the Canadair can still compete with the VLATs because most require a full blown major airport to operate from and the combination of on ground time is what slows them down. The Canadair reloads in 12 seconds without dropping much below takeoff speed and can operate from smaller airports. The VLAT has to land taxi load taxi takeoff and it will never approach 12 seconds.
If the VLAT was permitted to abbreviated approach and departure more time would be saved but if the nearest airport has RPT then it must join the circuit with what ever else is out there.