Air-attack supervisor flies over Etiwanda fire to assess burn area

An air-attack supervisor in a plane flew over the Etiwanda fire Thursday afternoon to pinpoint where the blaze was flaring up as hundreds of firefighters cut containment lines amid searing heat and dangerously low relative humidity, fire officials said.

Commanders overseeing the battle to control the raging wildfire in the San Bernardino National Forest near Rancho Cucamonga were evaluating information gathered from the flyover to decide whether to use aircraft to help battle the blaze, a fire official said Thursday afternoon.

“They flew over to check out the terrain and see what’s really going on,” agency spokesman Brian Grant said.

Three helicopters and two fixed-wing tankers were ready to make water and retardant drops on the blaze. But commanders on the ground were assessing wind and fire conditions.

Grant said winds were gusting between 25 mph and 30 mph. But he noted that wind direction and speed can quickly change in the steep canyons, creating dangerous conditions for pilots.

Temperatures were in the mid-90s and relative humidity was a dangerously dry 5%, fire officials said. Still, firefighters on the ground were making good progress battling flareups and cutting containment lines with hand crews and bulldozers, Grant said.

But, he said, “we’re not out of the woods yet.”

Around 700 firefighters from a number of jurisdictions were battling the blaze, which was 10% contained. Two firefighters received minor injures, the Forest Service said.

The blaze was first reported shortly after 8 a.m. Wednesday and quickly exploded in size amid powerful Santa Ana winds, extremely dry air and unseasonably high temperatures. Wind gusts above 80 mph grounded aircraft Wednesday too, complicating the task of fighting the fire as it zigzagged along the parched brush- and chaparral-covered hillsides. One gust of 101 mph was reported Wednesday afternoon.

No major damage had been reported as a result of the blaze so far. Fire officials said Thursday that one house sustained minor damage, but did not elaborate. More than 1,600 homes Wednesday were under mandatory evacuation orders, but those were downgraded to voluntary by the afternoon.

“The bad news is, we’re going to have some tough, hot, dry, windy conditions to fight that fire, and in case any other fire gets started, it’s going to spread quickly,” said Miguel Miller, a forecaster with the National Weather Service. “The good news is, conditions will improve this afternoon.”

robert.lopez@latimes.com

Twitter: @LAJourno