For neighborhoods in Southern California, the sound of low flying aircraft means help is nearby. An "air war" is being fought above many communities, large and small, by 23 huge airplanes and nearly 50 helicopters -- all waging a nearly round the clock air raid on the California wildfires.
They drop water on hot spots, specialized foam on stubborn areas that water can't put out, and flame retardant ahead of fire lines as a last line of defense. It is a tricky business, flying low, often near mountains, in high winds and with poor visibility.
Longtime firefighting pilot Matthew Collins told ABC News, as a last resort, he dumps his water early to lighten his load and pull out of a bad situation.
"You're anticipating things going badly ... if I'm flying at the slope, I'm always thinking, if things start going badly, I can bail out one way or another," Collins said.
ABC's Neal Karlinsky spent the day at a makeshift air base in Malibu where the choppers come in to refuel and reload their water tanks. Smaller helicopters take 300 gallons of water, while larger ones can hold up to 2,500 gallons.
The crews make their drops all day long, and some of these pilots can make between 45 and 50 drops in one eight-hour shift.
They have their own air traffic controllers flying above — one for planes and one for helicopters. And these pilots don't just protect homes. Sometimes, they save firefighters overwhelmed by fast moving flames.
"When there's companies on the ground that are in trouble, or possibly getting close to the point where they're in trouble ... our primary objective is to make sure the guys on the ground are safe," pilot Rick Wheeler said.
The demand is so great, specialized C-130 cargo planes, which can drop 3,000 gallons of water across a quarter mile of land, are now arriving on loan from the military.
The Santa Ana winds are still strong, but it doesn't seem to phase these pilots.
Dangerous as it is, they say their mission isn't over until the fires are out.