Friday, July 12, 2013 | 7:30 p.m.
As aircraft buzz Mount Charleston spewing red clouds of fire retardant, crews below are busy mixing thousands of gallons of the concoction that is slowing the wildfire creeping across the mountain.
As fast as the helicopters can pick it up — 2,000 gallons at a time — the support team on the ground makes it.
On Thursday, it was 40,000 gallons in just four hours, enough for each of the four helicopters working the fire to make five trips.
The fire retardant is essential to not only slowing the advancing fire but protecting firefighters on the ground.
“The retardant adheres to the fuels and retards the spread of the fire. It doesn’t necessarily put the fire out,” said Miles Hancock, air support group supervisor with the U.S. Forest Service.
“It supports ground operations so we can safely put crews into areas that otherwise would be unsafe for them,” he said.
The makeshift production plant — a cluster of several trucks and hundreds of feet of hoses — was set up Thursday in a dirt parking lot on Kyle Canyon Road, only miles from where crews are battling the blaze.
The manufacturing process starts with two large pools of water, which are refilled as needed by water tanker trucks. The water from the pool is piped into a large mixer on a semitrailer, where it is combined with a powdered retardant made of fertilizer and that unmistakable red dye.
The resulting mix is stored nearby in 5,000-gallon tanks, where the helicopters can fill their 2,000-gallon tanks before returning to the front line. Filling a helicopter’s tank takes 10 to 15 minutes and can be done without the aircraft ever having to land.
The helicopters also dump plain water in certain situations, usually when directly attacking the front line of a fire, Hancock said.
But oftentimes before water is used, the retardant is dropped to provide firefighters a safe path of approach.
Although planes and helicopters have been dropping retardant on the fire for several days, the mobile plant allows pilots to scale up those activities and provides a faster turnaround, Hancock said.
The helicopters were grounded midday Friday because of heavy winds from storms that also prompted a flash flood warning for Mount Charleston.
As of 2 p.m., it was unclear when the flights would resume.