Trial by fire

Evergreen says its 747 Supertanker will revolutionize aerial firefighting. Critics beg to differ.

By Ben Jacklet

The Portland Tribune, Sep 10, 2004, Updated Oct 30, 2009

Remember the Biscuit fire in Southern Oregon? The largest wildfire in Oregon’s modern history? “We would have cured that fire in two days,” Penn Stohr said of the 2002 wildfire that burned 400,000 acres. “That was such ideal terrain for the 747. It would have been absolutely perfect.”

Stohr, director of flight operations for Evergreen International Aviation Inc., does not lack faith when it comes to the Evergreen Supertanker.

The Supertanker is a Boeing 747 that Evergreen is retrofitting for firefighting. It would hold 24,000 gallons of fire retardant on board, allowing pilots to pour seven times the amount of chemicals onto wildfires. And rather than just dump the liquid via gravity, the Supertanker would spray it at calibrated pressures, creating a mist or a downpour, depending on the need.

McMinnville-based Evergreen is pouring millions of dollars into the Supertanker and touting it as a revolutionary addition to the nation’s aging fleet of firefighting aircraft, saving property, time and lives. But the project has its critics, and the questions they raise are sharp:

• Is the 747 too big and clumsy to fly low near fires in mountainous terrain?

• Will taxpayers end up footing the bill for a lucrative contract to a company with a long history of government contracts?

• And if the idea of a big plane dropping large volumes of liquid from the sky is so great, then why has the Forest Service repeatedly refused to use a Russian-built plane with similar capabilities, even as wildfires have raged over the past decade?

Scoffing greets brainstorm

Stohr said Evergreen first presented the idea of converting a 747 for firefighting to the Forest Service about 10 years ago. “We were kind of laughed out of the meeting,” he recalled.

Things have changed. This spring the Forest Service grounded its entire fleet of firefighting air tankers after a string of accidents raised safety issues. Ten air tankers have since been recertified, but the Forest Service has yet to complete a long-term plan for replacing the planes that were taken out of commission.

An ongoing lawsuit over environmental damage from fire retardant adds to the uncertainty.

Evergreen tested its first version of the Supertanker in Arizona in March and April, spraying 536,000 gallons of water and chemicals in a series of releases mostly at altitudes of 400 to 800 feet.

The Supertanker flew at only half-capacity, and real fire conditions were not simulated. But Stohr said it was clear that the basic design was sound.

“It worked so well at high altitude that we brought it down as low as 300 feet,” he said. “Our best altitude is 400 feet for accuracy. The retardant just turns into mist. It feels like rain below.”

Since then, Evergreen engineers have pulled out the plane’s prototype tank and built a larger one. Stohr said they hope to install it soon, test the plane at full capacity in October and, if all goes smoothly, demonstrate it on a live fire in Southern California as early as November.

Evergreen also is looking into other potential uses for the Supertanker, such as neutralizing oil spills and decontaminating the air in response to a bioterrorism attack.

Air tankers generally charge the Forest Service a fee to be on standby plus an hourly rate for operation. Earlier reports pegged the Supertanker’s cost as high as $20,000 per hour, but Stohr said it was too early to know the cost.

Contractors who fight wildfires on the ground say they find the concept of the Supertanker compelling, but they wonder how accurate and safe it would be.

“If they fly it high you’d get problems with vaporizing and drifting,” said Ted Atkinson, owner of LaGrande-based Athic Enterprises. “And if they fly it low it’d be scary. You wouldn’t want to be in (a 747) skimming over treetops, and I wouldn’t want to be on the ground near one.”

Forest Service officials originally had expressed skepticism about the project, but recent interviews indicate that they may be warming to the idea.

“I applaud Evergreen’s efforts,” said Jon Rollens, aviation manager for the Forest Service’s Pacific Northwest Region. “They’ve done it on their own nickel and made some real progress. (The Supertanker) certainly may have a niche in the firefighting business.”

But not all observers are impressed. “I’m very aware of what Evergreen’s doing,” said William Kauffman, an aerospace engineering professor at the University of Michigan. “I think it’s stupid, to put it simply.”

Kauffman noted that the 747 had an extremely flexible airframe that was designed to fly at 35,000 feet, not 400 feet off the ground in the vicinity of a roaring wildfire.

“To put an airframe this big that low, going that slow in the turbulence of a fire is going to wipe out the airframe,” Kauffman predicted.

Kauffman said he had spoken with an engineer at Boeing who agreed with him off the record and three pilots who told him they would refuse to fly the Supertanker.

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