July 17, 2007 In the vast array of pseudo weapons of war we constructed as kids, the waterbomb was one of the most effective. The right brand of balloon, filled with the right amount of water, could deliver a telling blow over a fair distance, particularly if you had gravity on your side. In a tale of creative innovation centred around the same idea, Boeing and plantation manager Weyerhaeuser are testing a new Precision Container Air Delivery System (PCADS) technology designed to make aerial firefighting more effective. The theory is that dumping fire retardant from the air as a bulk liquid is not the best way to deliver it effectively, so the water or flame retardant is broken into discrete volumes inside dozens of special cardboard containers. The boxes are then dropped from a plane in groups, breaking apart in midair to release their payload far more accurately on the fire below. If it works, and it looks very promising, PCADS will significantly expand the number of planes capable of taking part in aerial firefighting.