A think tank says the U.S. Forest Service should pursue a much different strategy for using airplanes to fight wildfires, one that relies more heavily on planes that scoop up water on the fly and less on air tankers that drop fire retardant chemicals and need to be reloaded on the ground at airports.
Forest Service Chief Tom Tidwell says he agrees with many recommendations in the long-awaited report released Monday by the RAND Corp., but not that one.
“We disagree with that because we feel some of the information they used is inaccurate,” Tidwell told the Associated Press.
The lead author of the report, Edward Keating, stood by the cost-comparison data, which RAND drew from recent government contracts for water scooping planes in the U.S. and elsewhere.
“We are very adamant about the validity of our scooper cost estimates and disagree strongly with Mr. Tidwell on that point,” Keating said.
Right now, the Forest Service doesn’t contract for any water scoopers to fight wildfires. A blueprint released in February for modernizing the aging air tanker fleet – which right now is made up largely of 60-year-old Lockheed P-2V Neptunes, a former military plane – mentions the possibility of using water scooper planes.
However, none of the eight planes listed in the Forest Service’s Large Airtanker Modernization Strategy is a water scooper, such as the Canadair CL-215. Specifically designed for bombing water on wildfires, the amphibious plane can fly low and scoop up more than 1,400 gallons from a large body of water in just 12 seconds.
Water scoopers also aren’t among the seven large air tankers being expedited to the Forest Service contract fleet this year and next under a bill President Barack Obama signed in June.
Water scoopers are used extensively in Canada, as well as by Los Angeles and San Diego counties, which every year contracts Canadian water scoopers to fight fires. The U.S. Bureau of Land Management in Alaska and state of Minnesota also use water scoopers, said Keating.
“These folks are universal in their praise for the vehicles,” Keating said. “We think for a sizable percentage of fires, in particular those that are relatively proximate to water sources, that scoopers can replace air tankers.”
At least two-thirds of fires have occurred within 10 miles of open water that would be accessible to a water scooper, according to the RAND report.
Water typically is used differently against wildfires – dropped directly on flames rather than close by the fire to try to slow its spread. Gallon for gallon, water is half as effective as retardant at slowing down wildfires, but a scooper can make many more drops compared to an air tanker when a fire is close to water.
The Forest Service might consider substituting a few water scoopers for water-dropping helicopters but won’t contract for scoopers instead of retardant-dropping air tankers, Tidwell said.
“They’re not as accurate as the large helicopters. But in certain situations where we have a water source that they can scoop out of, then we think that this is one of the things we’re going to look at,” he said.
Water scoopers need to fly lower than air tankers, Tidwell said, because water needs to be dropped from a lower height to be effective.
“Water, if it’s dropped at a higher altitude, you can lose a lot of it just through evaporation. And then the wind will move water around a lot more than it will retardant. Retardant is much heavier, it’s denser. So we can fly the planes a little bit higher so it’s safer for the pilot,” Tidwell said.
The RAND study was a cost-benefit analysis of the social and economic toll of wildfires as well as cost of using aircraft to fight them. RAND recommended two combinations of contracted helicopters, scoopers and air tankers based on different assumptions about the local availability of equipment and firefighters:
• A fleet consisting of five air tankers that can carry up to 3,000 gallons of fire retardant slurry and 43 scooper planes that can hold up to 1,600 gallons of water.
• One air tanker that can carry up to 3,000 gallons of fire retardant, two helicopters that can carry up to 2,700 gallons of water, and 15 1,600-gallon scooper planes.
One problem with using scoopers in the West is many large bodies of water are full of boaters during the summertime, pointed out Mike Archer, a wildfire consultant who compiles the Wildfire News of the Day newsletter.
“It’s something they would have to concern themselves with,” Archer said. “You’ve got to have time to clear people out of the way to use scooping aircraft.”
The chance that water scoopers could spread destructive invasive species, such as quagga mussels or zebra mussels, is another concern, he said.
The present fleet of large air tankers used by the Forest Service at the height of this summer’s wildfires numbered around 20.
They included 10 P-2V Neptunes, two of which crashed in early June. One of the crashes killed two pilots. The crashes reduced the number of P-2Vs to eight.
Another crash in the Black Hills of South Dakota on July 1 killed four North Carolina Air National Guard members and reduced to seven a fleet of military C-130s fitted to drop fire retardant.
The RAND report has cost the Forest Service around $800,000. The Forest Service commissioned the study in 2009. RAND provided an initial study the following year and completed follow-up research last year, Keating said.