CEDAR CITY - A steady drone has been heard over Cedar City for the past four days as air tankers fighting a series of fires in southwestern Utah have come and gone from the city's airport.

David Ricks, assistant fire-retardant manager of the Cedar City Air Tanker Base at the airport, has been loading the planes more than 60 times a day.

The intended target of the aircraft this week has been the Blue Springs fire, which has burned about 12,260 acres along Interstate 15 and threatened the town of New Harmony.

The planes were also being loaded last week to help fight the Red fire and West Side Complex fire, which have been contained after burning nearly 70,000 acres of land fueled from an exceptional spring growth of grasses that are now tinder dry.

Ricks said the retardant - a thick water-diluted mixture of ammonium, nitrate and salt - is held in 10,000-gallon tanks on the ground that are refilled six times a day from tanker trucks.

"I use about 122,000 gallons of retardant a day," said Ricks, taking a break from the incessant parade of aircraft landing and taking off from the airport where they are also fueled.

Five of the country's fleet of 10 heavy air tankers are committed to containing the fire that forced the evacuation of New Harmony on Monday night, said incident commander Rowdy Muir.

Among the tankers are P3 Orions and P2Vs, which hold 2,000 gallons and 2,453 gallons, respectively, of fire retardant; six single-engine air tankers, which carry 700 gallons of the chemical; and three helicopters, which refuel at the base and are used to drop water on the fire from buckets filled at lakes.

Ricks said operations can begin any time of the day and last until about a half-hour after sunset.

The base also fuels the planes that lead tankers to their drop targets.

Cliff Naveaux has been fighting fires for 32 years, the past 18 years at the controls of a lead plane.

Naveaux said he started flying after losing a leg in an avalanche in 1987. Before that he was a smoke jumper, bailing out of planes to attack fires in remote locations right after they start.

"At the time I lost my leg I had some aviation experience and wanted to stay in fire," said Naveaux, who is allowed to fly eight hours per 14-hour shift.

He also helps coordinate helicopters and the faster flying single-engine air tankers.

"What we want to do is coordinate the air attack with our line and bulldozer crews," said Naveaux, who works for the U.S. Bureau of Land Management and is based in New Mexico.

He first coordinates with an air attack operations specialist who is in the twin-engine King Air plane he flies or who is in a separate aircraft.

He flies on fires wherever they are burning in the country from Alaska to Florida, but no matter where the fire is, the objective is the same.

"You want to lay the retardant faster than the fire is burning," he said. "If you can't out-gun the fire, then you are playing catch up."

mhavnes@sltrib.com