By Ron Jones

SACRAMENTO (CBS13) — Firefighters are beginning to get the upper hand on the largest wildfire burning in California as the Rocky Fire remains at 20 percent containment.

Flames have charred more than 68,000 acres in Lake, Yolo and Colusa counties, and has destroyed 39 homes and 52 outbuildings. More than 6,900 structures remain threatened.

Firefighters said Wednesday was the calmest day they’ve seen since the fire started eight days ago, and they expect to have the at-times unpredictable fire completely contained in the next week.

Aerial drops will be a key part of containing the flames.

Lt. Col. Ryan McCreight with the U.S. Air Force Reserve is one of several pilots flying the massive C-130s from McClellan, carrying only a massive retardant supply tank. The plane is normally a workhorse in military missions, dropping troops and supplies in hostile combat zones.

“We flew three sorties Monday afternoon and five yesterday,” he said of the offensive effort against the Rocky Fire.

Because the fire is so stubborn, their mission is to land, refuel, airdrop retardant and repeat several times a day from morning to night.

“It does get tiring after awhile with the heat and everything but we’ve got a lot of folks out here helping us out,” he said.

Pilots like McCreight are part-time citizen airmen who fight fires in their off time. He flies for Southwest, while others fly for United. The seasoned pilots say the same superior service they provide for passengers in the air is passed on to homeowners on the ground during the firefight.

“Within the parameters that we’re given we really push hard to get the mission done effectively because that could be the difference between someone losing everything and saving their homes,” he said.