you guys from the forces aren't going to like hearing this, but having watched a couple of the videos, i think that a couple of AS350s with longlines and good lifting pilots would have kept up, or maybe beaten the chinook. On the videos i saw they took 2 minutes to place the bags that they had transported to the Dam. now if you are doing 6 bags in 6 minutes, and it takes the same time to hook up the 6 bags, that is 4 minutes of hovering around out of every 6 minutes, therefore roughly 1 minutes flight each way.
Any utility pilot worth his pay would have the bag placed in a couple of seconds, so they would be doing at least 2 trips to one of the RAF, maybe more.
Economically there is no way that you can say the RAF doesn't have a cost, the cost would be known, and the cost would be way more than doing it commercially, even though the RAF need to be paid anyway, and it is good training for the RAF to go and do a good job supporting the community.
And yes, far cooler watching a chinook cruising around than a couple of froggies doing laps...
And i don't actually care, as i am pretty sure that they weren't going to get me to come all the way from NZ to do the job, so i am just looking at the logistics, timing and cost of the operation.