Despite passing certification with the Federal Aviation Administration and signing a firefighting contract with the U.S. Forest Service last fall, the Boeing 747 Evergreen Supertanker will not be deployed in 2007.
Last week, nearly one million acres were burning in Idaho, including the 653,100-acre Murphy Complex Fire on the Idaho/Nevada border, which cut power to the Duck Valley Indian Reservation for a week. Could the world's largest water-bomber, capable of laying down a one-mile-long swath of fire retardant, have played a role in dowsing the largest wildfire in the nation?
"The work at NIFC is a kind of chess game," says Mike Apicello, spokesman for the National Interagency Fire Center in Boise. "People try to get to fires while they are still small in order to protect people and property. One part of the game is to get aircraft pre-positioned for firefighting."
Currently, the NIFC fleet of large tankers is comprised of 16 heavy air tankers, each capable of dropping 3,000 gallons of fire retardant in one fell swoop to aid firefighters on the ground. The cost of operating a conventional tanker is $5,000 per hour. By contrast, the Evergreen Supertanker has a payload of 24,000 gallons, eight times the C-130, and would cost the Forest Service as much as $20,000 per hour.
According to Kim Frederick of NIFC, air tankers of any kind can only be used effectively in combination with a strategy on the ground. "Ground crews are cutting narrow control lines with hand tools and chainsaws and then burning out the area inside the control line in order to deprive the fire of fuel," he says. "The air drops generally don't put fires out, but they can buy the ground crews time to build their control lines. It is a complex process, and timing is critical because ground crews may have to judge where a fire will be in four days time."
According to Frederick, the use of large tankers is best suited to grass and brush fires burning on flatter topography, a fit description for much of the Murphy Complex Fire, which began as five separate fires, eventually burning together. Yet Frederick points out that high winds would have rendered air drops ineffective during three crucial days of the fire in which 342,000 acres were burned.
"The Supertanker would be an expensive resource," says Pat Norbury, U.S. Forest Service National Aviation Operations officer. Norbury says the Evergreen Supertanker was developed in response to a call from federal firefighting agencies for innovation in water-bomber designs. The call went out after the 2002 crash of a conventional C-130 tanker in Nevada, which claimed three lives. A subsequent investigation by the Washington,D.C.-based National Transportation Safety Board grounded the entire Forest Service fleet of 36 1950s-era C-130 tankers, three of which had crashed in recent years because of wing stress fractures.
As a result of the investigation, national regulatory pressure came to bear on what had been a casual system of firefighting. It was a system that had previously involved entrepreneurial and intrepid pilots contracted by private companies to fly all manner of aircraft, including helicopters, tankers and single-engine airplanes.
"The NTSB determined after the investigation that the Forest Service was responsible for the continuing air-worthiness of any aircraft contracted to fight fires on federal lands," says Norbury. "Before that time, they had only to meet FAA requirements on their own."
Norbury's office has worked with NASA engineers and Sandia Laboratory officials in New Mexico to develop guidelines for maintenance standards for its firefighting fleet. As of this summer, only 19 of the original fleet of 36 heavy tankers have passed certification and are back in operation. None of them are C-130s, but have been replaced with P-2V Neptunes and P-3 Orions. NIFC is uncertain how many of the tankers, if any, were used in the Murphy Complex Fire.
Norbury has also worked with Evergreen for the past two years during the re-design of its Supertanker and says the airplane has received interim approval by the Interagency Air Tanker Board.
After testing the aircraft in California last year, Norbury was quoted in Aviation Week magazine saying, "The entire team was surprised at how maneuverable the 747 was in the confines of a fire traffic area. They concluded that the Evergreen 747 appears to be a very viable resource for fire retardant and water delivery. We expected much larger [flight] patterns and less utility in rough terrain. But it was actually quite maneuverable. It had no problem working with the lead plane [a King Air 90] and making drops."
"We are anxious to see what it can do," Norbury told BW last week. "The Supertanker fits one of our general strategies, which is to apply retardant in a long line, but the question remains: Can we tactically deploy that much fire retardant in a fire?"
Fire retardant is only a retardant. Without ground crews working on the fire lines, the fire can just burn right through.
"We are interested in anything that appears to be viable in fighting fires," she says. "But this aircraft has not been out on a fire, even for a test. And it won't be until it has satisfied all our criteria. The company still needs to develop a continuing air-worthiness program‚ which is a maintenance and inspection system to monitor specific stress points on the aircraft under operational loads during fire fighting conditions. We don't know if they [Evergreen] are going to be staffing this."
Garrett Brown of Evergreen Aviation says his company has spent more than $15 million in the development of the supertanker before taking it off contract this summer with the Forest Service, and re-fitting it for cargo use in the Middle East. "We will make it available again in May of 2008," says Brown, though he would not comment on the final deliberations he faced before terminating Evergreen's contract. Instead, he said only that his relationship with the Forest Service was still a good one, and that the details of he decision are "proprietary information."
While federal officials in Idaho are still developing policies for certifying a new generation of firefighting planes, California officials, unhindered by federal procedures, moved forward in 2006 with a supertanker of its own.
Tin Tanker Corporation's DC-10 jumbo jet was flown for the first time last year under contract with Cal Fire. The DC-10 carries about half the payload of the proposed 747, but according to Bill Payne, chief of flight operations for Cal Fire, "It's been fantastic. We used it last year on six fires and dispensed 200,000 gallons of retardant. It carries 12,000 gallons of retardant and can lay a mile line 50-feet wide. It has absolutely been a success."
The DC-10 will re-deploy next week under contract with Cal Fire after being grounded for several weeks for repairs. Earlier this summer, the DC-10's left wing clipped through pine trees on a ridgeline while fighting the White Fire in southern California, yet the airplane was landed successfully without injuries.