Crab
What is the roads closed got to do with it ? If you are the emergency services then you open them !
Lets assume that the bags are a mile from the drop zone, I suspect and knowing the area one could get them way closer. Then the 350 will have a turn round time of around 2 mins per bag. So 400 bags is 800 minutes or 13.3 hours call it 15 to be on the safe side.
We would have 2 pilots so at a real push could do those bags in a day
AS 350 £15000
Positioning £ 4000
Crew x 2 days £ 1800
Jet a1 £ 1800
Contingecy 15% £ 3120
So £ 25720 is the bill my company would charge. I might be wrong on teh distance, but that would be the advantage of the 350 and a longline.
Did you notice the bag rolling down the hill on the news ?