A small army of firefighters continues to make slow progress against the Rim Fire burning in and on the western edge of Yosemite National Park. Fire officials say the fire has burned about 202,000 acres. That’s a little larger than the area of all of New York City or almost two-thirds the size of the city of Los Angeles. The fire’s just one-third contained. But officials also say the situation would be worse without the help of the biggest weapon in the firefighting arsenal: a pair of refitted airliners that wildfire crews call the “Big Boys.”
The two DC-10 jumbo jets — the kind of passenger airliners you might once have ridden to London — swoop down at strategic moments over the firefighters on the ground. Each plane can dump 100,000 pounds of iron-red fire retardant, or “mud.” That’s at least four times more than a standard air tanker.
“It’s kind of the difference between a Dixie cup and a Big Gulp,” says U.S. Forest Service spokesman Mike Martin.
Rick Hatton, CEO of 10 Tanker Air Carrier, stands next to a DC-10 jumbo jet.
The three-engine jets are owned and flown by the firm 10 Tanker Air Carrier. Owners say they’re the only two retrofitted firefighting DC-10s in the world. And both are being used in the battle against the Rim Fire.
“We’ve taken all the people out, all the cargo out, all the seats out,” says Rick Hatton, 10 Tanker’s CEO. “In its place we’ve put this 100,000-pound external (tank) on the belly, and then we’ve light-loaded it with fuel because we’re never going more than four or five hundred miles instead of going all the way to Europe.”
The Big Boys are flying their missions out of Castle Airport, a former Air Force base outside Merced, in the San Joaquin Valley. As a crew fuels one of the jets for its next mission, a smoky haze hangs over the Sierra Nevada, with a white plume rising over the mountains.
“It looks like a mushroom cloud!” Hatton says.
Rick Hatton, CEO of 10 Tanker Air Carrier, demonstrates that fire retardant is mild enough stuff to touch.
When the DC-10s reach the fire zone, they come in at precisely 150 knots (about 165 mph) and just 200 feet above the treetops. Then the jet drops a ribbon of retardant up to three-quarters of a mile long and 60 feet wide. Customized software controls the tank doors to release the red liquid -- a mixture of water and a nitrogen-based powder similar to fertilizer -- at a constant rate of flow. To the non-aviator, the planes look surprisingly maneuverable.
“You don’t tend to think of airplanes like this turning steeply because when you ride in them from L.A. to New York, they don’t turn steeply,” Hatton says. “But they can.”
The massive retardant drops are designed to slow down fires long enough to give ground crews a chance to cut fire breaks, using bulldozers, picks and shovels.
At the main Rim Fire base camp, about 50 miles from Castle, Forest Service spokesman Lee Bentley says this is the first time he’s seen two of the giant tankers used on the same fire. He says their impact is “tremendous.”
The big planes cost more than conventional air tankers. Actual costs can vary by day, but officials on the Rim Fire are budgeting $12,500 an hour for the DC-10s, compared with $8,700 an hour for their smaller cousins.
The Nevada company 10 Tanker Air Carrier debuted its second retrofitted DC-10 fire plane last year. Sometimes the two jets fight separate blazes, but the Rim Fire is using both.
Hatton argues that considering how much more “mud” the DC-10s drop per flight, it’s actually a significant cost savings. He’s hoping the Forest Service finds the Big Boys valuable enough to have him build more.
“We’d like to build a fleet. We think the nation needs six or seven or eight of these aircraft,” he says.
Back at the airfield, pilot Kevin Hopf sits at a table in the cavernous, empty body of the plane, doing paperwork. He’s already made five runs today. He says he’s been fighting fires from above for years, and the Rim Fire is a big one.
“I think everyone’s in for a long haul here, unless Mother Nature cooperates and dumps some rain on us,” he says.
Minutes later, the call comes for another flight.