Firefighters still battling the wildfires in the Western United States could sure use some more help from above.
Air tankers and helicopters that can drop water or flame-retardant chemicals have provided some relief. But some companies think such airborne attacks are just a drop in the bucket compared to their proposed future tools.
Wetzone Engineering in Huntington Beach, Calif., thinks it has a surefire idea. To fight big forest blazes, why not use a big blimp?
Engineers at the company propose designing and building a 1,000-foot-long airship that could carry about 264,000 gallons of water — nearly 100 times the capacity of the C-130 transport planes currently in use by the U.S. Forest Service.
Steady Manmade Rain
An array of nozzles slung underneath the dirigible would control the flow of water and could drop nearly 53,000 gallons per hour. Water cannons also mounted underneath could provide targeted water delivery to particular
Officials at Wetzone say that aside from the huge water capacity, their blimp offers other advantages over traditional air bombers.
Since it's noncombustible helium that gives the gigantic airship its lift, the proposed blimp could loiter over a forest hot spot much longer than any airplane or helicopter. In fact, the engineers even designed a way for the blimp to refill its voluminous internal water tanks without leaving the scene of the flames.
The engineers' designs call for a special "catch basin" to be installed along the length of the blimp's top. Passing aerial tankers such as C-130s and Chinook helicopters could then fly over the blimp and dump their water loads into the blimp.
The result, says Wetzone, would be an aerial vehicle that could create a nearly continuous artificial rainfall.
A Big Bag of Wind?
But others aren't convinced that the Wetzone bird would fly.
Carl Bambarger, aviation program leader for the U.S. Forest Service's technology and development center in San Dimas, Calif., says firefighting blimps have been proposed — and rejected — years before for several reasons.
For one, he doubts that a nonrigid vehicle such as a blimp would survive over the hot and turbulent airspace of a major forest blaze.
"Massive forest fires create their own weather patterns," says Bambarger. "Anywhere from 200 to 300 feet above the fires is a very violent environment and blimps just aren't built to withstand much turbulence."
Bambarger also questions the validity of the blimp's aerial capability.
"If multiple scoopers are needed to keep this thing full, I'm basically carrying the same amount of water," says Bambarger. "Basically, I'm using one vehicle to fill another. So why not put it down directly? It doesn't make any sense."
Wetzone officials say the blimp is still on the drawing board, so it is possible to overcome any shortcomings. For example, the company says it is designing the blimp to fly at altitudes of over 3,000 feet — well above any turbulence that may be caused by the heat of fire.
The company does note that a full working prototype is probably around three years away. And officials don't know how much such a blimp would cost to produce.
A More Modest Proposal
Still, other blimp makers believe that lighter-than-air vehicles could one day have a place in fighting forest fires.
Robert Boyd, chief technology officer for SkyCat Technologies in Santa Monica, Calif., says his company has been developing a high-performance blimp called the SkyCat 20. Originally intended as a cargo blimp that can lift 20 tons, Boyd says the SkyCat blimp could easily adapt to the role.
At roughly one-fifth the size of Wetzone's design, which Boyd has seen, the SkyCat 20 would be able to carry only 5,000 gallons or so of water. But that's still two-thirds more than what a C-130 can carry, says Boyd.
What's more, Boyd says SkyCat has gone beyond the drawing board stage. The company recently tested a small-scale prototype that "flew beautifully," he says.
The company hopes to get the SkyCat certified for flight by the Federal Aviation Administration soon.