USA — Two aviation companies are trying to convince the U.S. Forest Service that converted jumbo jet airliners are a great new tool for dropping super-size plumes of pink fire retardant on wildfires, whether they are on flat ground surrounding Los Angeles or in rugged mountains.
After an initial flicker of interest, the Forest Service is being more cautious about using DC-10s and 747s to do the job now done by smaller, propeller-driven planes. Although California is using a DC-10, federal officials want to know more about both safety and cost before making any commitments.
A NASA evaluation has concluded that the jumbo jets can do the job in flat or rolling terrain, but they do not have the maneuverability to handle rugged mountains.
And a study will be done to see if the bigger bang is worth the extra bucks, or as Forest Service official Pat Norbury puts it: “Are they producing value for us besides just a great CNN shot?”
NASA will brief Forest Service officials April 7 in Boise, Idaho, on its report.
“It basically says, yes, these aircraft can be operated within the fire environment within certain restrictions,” said Norbury, national aviation operations officer for the Forest Service at the National Interagency Fire Center in Boise, Idaho. “You can’t put them in steep, rugged terrain. They can’t turn fast enough.”
Fighting wildfire accounts for more than 40 percent of the Forest Service budget. Last year it spent $1.5 billion putting out wildfires, and 16 percent of that went to air operations.
The size and severity of wildfires has been steadily growing, with acreage doubling since the 1990s. Some studies blame the increase on global warming and the longer, drier summers it has brought to the West. And more people have built houses in the woods, making it tougher to fight wildfires and increasing losses.
Rick Hatton, managing partner of 10 Tanker Air Carrier, LLC, of Victorville, Calif., says the company’s McDonnell-Douglas DC-10 jet can turn as sharply and maneuver as well as the big military surplus propeller-driven planes in the air tanker fleet.
“Any airplane turns by a function of the square root of the true air speed and the angle of bank it is subjected to,” he said. “A Piper Cub or an A380 (the largest airliner in the world) put into the same bank make the same turn.”
Hatton said no one is talking about sending the jumbo jets down narrow twisting canyons. They have flown 245 missions on firesmany over mountainous terrainfor the California Department of Forestry and Fire Protection and can drop the retardant from a higher altitude, or in the case of a sharply angled ridge line, make two passes.
“Putting a new aircraft into service to fight fires meets resistance just like putting a new tank in the Army or rifle in the Marine Corps,” he said.
NASA spent nine months on the report of nearly 400 pages, interviewing personnel, flying the aircraft with tanker pilots, and using flight simulators.
“It was a very legitimate science-based approach,” Norbury said.
The Forest Service withdrew an earlier call for bids on a super-size air tanker, and Norbury said it has no immediate plans to issue another. It can, though, call on 10 Tanker because of the California contract.
Meanwhile, the Forest Service continues to work with 10 Tanker and Evergreen International Aviation, Inc. of McMinnville, Ore., which has a Boeing 747 Supertanker, Norbury said.
“We’ve put five years and $50 million dollars into this program,” said Jim Baynes, Evergreen sales manager. “Let’s get the thing out there and see what it can do.”
Evergreen is eager to use the 747 for other projects, as well, such as dispersing oil spills.
Cal Fire is in the third year of a $15 million contract with 10 Tanker to provide exclusive use of its airplane, which also gets $5,500 for each hour it flies. A second plane is on call.
Cal Fire uses helicopters and smaller air tankers, the S-2T, for initial attack, which catches more than 90 percent of fires when they are still small.
But the DC-10 has been used in big fires, particularly when a long, heavy line of retardant is needed along a ridge line, said Jim Winder, battalion chief in charge of air operations on the Riverside Unit.
“Overall, it’s been positive,” he said. “It’s another tool in the toolbox.”
The bigger planes have to fly at a higher altitude and faster speed than the smaller ones, and require a lead plane to guide them in to a drop and test the stability of the air for pockets that could force down the bigger plane, said Winder.
They also represent a huge leap in payload: the DC-10 carries 12,000 gallons and the 747 24,000 gallons, compared to 1,200 gallons for the S-2T.
“The very large air tankers will never be a replacement for the air tanker fleet,” Winder said. “We can’t afford to wait for a lead plane to come around and do trial turns.”
Since a DC-10 clipped some trees on a retardant drop in 2007, Cal Fire has required them to maintain an altitude of 300 feet, which gives them the buffer to absorb a drop in altitude due to a sudden change in air pressure, Winder said.
Andy Stahl, director of Forest Service Employees for Environmental Ethics, a conservation group, said he thought the Forest Service would ultimately decide against the jumbo jets.
“I don’t think bigger is where the smart people of this new administration want to go,” Stahl said. “The challenge with fire policy is not met by a bigger bucket. It’s met by being smarter about where we build houses, how we build houses, and how we manage fire, not how we try to stamp it out.”