USA In 2015 and 2016 the Aerial Firefighting Use and Effectiveness (AFUE) study collected data on 7,000 drops of water or fire retardant on wildfires. This is partially in response to demands by Congress and the Government Accountability Office to provide actual data to justify the huge expense of using helicopters and air tankers on fires. Anecdotal information generally indicates that aircraft are effective under certain conditions to slow but not extinguish fires, however something more conclusive is needed when answering questions in front of a Congressional committee making decisions about allocating hundreds of millions of dollars.
And, we have not been able to determine, definitively, how many air tankers and helicopters are actually needed. The Forest Service likes to point to one of more than a dozen air tanker studies, the 2012 Large Airtanker Modernization Strategy, to answer this question, but it does not address the quantity of aircraft that are needed.
For some reason NIFC never tells you what the acronym seen in the film, WFSTAR, stands for, but it is Wildland Fire Safety Training Annual Refresher.