How aerial firefighters attack wildfires with air tankers, Broncos, and Super Hueys


If air-traffic controller is one of the most stressful jobs and firefighting is one of the most dangerous, then you get an idea of what it’s like to be an air tactical group supervisor.

Aircraft that douse flames with water and bright red Phos-Chek fire retardant are a common sight in California. Aerial firefighting requires municipal, county, state and federal agencies to communicate on the ground and in the air.

Fire Capt. David Hudson has been an air attack group supervisor for 2.5 years and is based at Hemet-Ryan Airport’s air attack base, which deploys aircraft to fires from the Pacific Ocean to the Colorado River. Hudson says, “Cal Fire has air bases strategically located so aircraft can reach a fire in 20 minutes after a call.”

When above a fire, Hudson sits in the back of an OV-10 Bronco and coordinates with the ground commander on a strategy to get ahead of the fire and manage all the aircraft entering the fire zone.

“The dozers and guys on the ground put the fire out. Our job is to try and get ahead of the fire and box it in,” Hudson says.

How the fire zone works

Refill and return

Phos-Chek is made by a company in Ontario. If the air base in Hemet needs more, a truck will refill its supply in about an hour. The retardant is a mix of a chemical salt, water, clay or a gum thickening agent and a coloring agent.

Laying it down

In addition to coordinating where aircraft should go, the air tactical group supervisor tells pilots how much retardant coverage is needed.

A longer line is generally needed for grass fires. Brush fires, with their heavier fuel, require a more concentrated drop.

This chart shows a 1,200-gallon heavy air tanker’s coverage length, in feet.

Covering California

Cal Fire bases are positioned so aircraft can reach any place in the state within 20 minutes.

The supertanker based at McClellan Air Force Base and traveling 600 mph could be over Los Angeles within 35 minutes.

Frequent flyers

Most of Cal Fire’s aircraft were purchased from the Department of Defense.

OV-10 Bronco (maximum speed: 280 mph)

Cal Fire uses these for aerial command and control of aircraft on wildfires. The crew consists of a pilot in the front and an air attack supervisor in the back. Pilots for Cal Fire cannot fly more than seven hours in a day.

Grumman S-2T (maximum speed: 270 mph; gallons carried: 1,200)

By 2005, all of Cal Fire’s air tanker fleet had been converted to S-2Ts. The tankers are used for fast initial attack drops of fire retardant. They are flown by a single pilot who must often fly in steep canyons and strong winds and just hundreds of feet off the ground.

UH-1H Super Huey (maximum speed: 126 mph; gallons carried: 360)

All Cal Fire helicopters are flown by Cal Fire pilots, while air tankers and air tactical aircraft are flown by contract pilots. Helicopters can be used for medical evacuations, backfiring operations, infrared mapping of incidents and numerous nonfire emergency missions.

Where retardant cannot be dropped

Many places in Southern California have aerial retardant avoidance areas. These are mostly near waterways with sensitive species. The map below is from the U.S. Forest Service’s avoidance map viewer.

Sources: Cal Fire, National Wildfire Coordinating Group, U.S. Forest Service

Photos from Cal Fire and staff