DURANGO — On the northern edge of the Durango-La Plata County airport, a U.S. Forest Service facility supports aerial firefighting across Colorado and eight other Western states. The Durango Airtanker Base operates from May to September, allowing pilots to land, reload with retardant, and take off to wherever they are needed most.
The base is managed by the San Juan National Forest and has recently supported the Ferris, Babylon, Gold Mountain, Elk and Aspen Acres fires. It plays a critical role in supporting firefighters on the ground in controlling and containing fires of all sizes.
“It’s been an absolutely insane six weeks so people are pretty exhausted,” said Lorena Williams, public affairs officer for the San Juan National Forest. “Like I’m seeing my friends’ faces, and I’m like, ‘You guys need a nap.’”
Luckily, a break came July 22 when rain grounded aircraft and led to a slower day on the base. That’s the day that The Colorado Sun got an inside look at the facility.
Retardant on tap
At the center of the base are two reload pits where planes replenish their tanks with fire retardant and airplane fuel. The base mostly supports large airtankers, or LATs, which can carry 2,000 to 4,000 gallons of retardant per load, but can also support very large airtankers, known as VLATs, and single engine airtankers, or SEATs. In total, the base can push out over 20,000 gallons of retardant in an hour.
The St. Louis, Missouri-based Perimeter Solutions supplies Phos-Chek retardant to the Forest Service. At the Durango base, six tanks hold 10,000 gallons of retardant each.
A retardant base mixture of chemicals is combined with water and then loaded into tankers or helicopters, Williams said. The retardant can be mixed to different densities depending on firefighting needs and weight concerns of individual aircraft.
“It’ll mix on demand into a pump,” said AJ Mosher, a base manager who is qualified to mix retardant. “What we have is called a Canadian blender. It’s got two orifices, and you just open one, and it’ll get the mix ratio. We’re measuring salt content in the retardant to get it to a specific range. It just mixes on the fly as it’s going into the aircraft.”
Planes are not stationed at the base permanently. The aircraft are owned by contract companies and are considered national assets. They travel to the most urgent fires based on the threat to life, property and infrastructure.
“You can have a plane and its crew start their day here in the morning, and end up on a fire relocated at the Canada border by the end of the day,” Williams said.
The competition for resources is fierce across the country, but there can also be reshuffling of resources in close geographic proximity, Williams said. Last summer, the Rim Road fire was burning in sight of the airtanker base on the Southern Ute Indian Reservation when aircraft were redirected to the Elkhorn fire, which sparked north of Durango on Missionary Ridge.
The Durango base is home to the Durango Helitack team, which operates an AS-332L Super Puma Type 1 helicopter out of the base. When The Sun visited, the helitack team was on assignment out of state.
When a plane comes in to reload, a fixed-wing parking tender will stand at the nose of the aircraft and communicate with the pilot as they pull into the pit. The tender also communicates with the retardant crew and refueling staff. They will then work with a ramp manager to send the plane back to the taxiway and runway. SEATs take just a few minutes to relead, while the larger tanker models can take up to 15 minutes. The Durango base can pump out 20,000 gallons of retardant in one hour.
The planes are considered emergency vehicles so they can slot in ahead of other aircraft to take off.
At the height of the past month’s surge of fires in the state, the Durango base was working with 11 planes that were flying laps out to the fires and returning to reload.
Aerial operations
Inside the main base building, staff coordinate the overall operations of the base and how it fits into the national firefighting picture. Matt Hollinger, a base manager, was monitoring radios and computer screens in the operations room.
“Even though we did get some moisture and the ramp is empty right now, it doesn’t mean that we still won’t get aircraft out here just to help other bases,” Hollinger said. “If there’s stuff up north, we can also provide relief for some of the bases that are getting pretty swamped with other aircraft.”
Hollinger said dispatchers can also order reconnaissance flights across the San Juan National Forest and beyond, looking for smoke and reporting back the coordinates.
Such flights might occur after a night of thunderstorms when lightning can spark fires in remote areas. Hollinger had a map with hundreds of red dots marking strikes reported July 21 and 22.
A timekeeper keeps track of flight time, which the Forest Service pays out to the aircraft contractors.
Air attack platform
The base also includes a kitchen and rooms for crew to rest between flying missions. Outside, a grill and smoker barbecue setup on the patio is the pride of the Durango base. As staff enjoyed lunch, a Cessna Citation air attack plane was grounded on the edge of the ramp for maintenance.
Air attack planes fly at the highest altitude and are tasked with communicating with aircraft and firefighters on the ground. An air attack group supervisor sits next to the pilot and operates the radio and communications. The supervisor communicates with nine different radio channels, on both AM and FM frequencies, said Paul Lemmon, a group supervisor trainee.
Lemmon recently provided air attack on small fires south of Durango.
He described what is referred to as an air attack stack. At the bottom of the stack, helicopters fly at 1,500 feet altitude, while airtankers sit at 2,500 feet. Air attack flies at 3,500 feet and keeps an eye on the entire aerial operation.
Air attack staff like Lemmon come from wildland firefighting backgrounds rather than aviation backgrounds, because air attack often strategizes with on-the-ground firefighters about next moves such as retardant drops.
“A good air attack is taking a lot of pressure off those firefighters on the ground,” Williams said. “He’s helping make decisions, recommendations to some sometimes very overwhelmed ground crew.”
On smaller fires, air attack can direct a tanker to drop retardant lines and quickly slow the initial spread of the fire, Lemmon said. On larger fires, air attack will consult with firefighters below to find the most strategic locations for drops.
While retardant helps stop flames from advancing across the landscape, water is useful in lighter fuel loads. For instance, planes recently scooped loads of water out of McPhee Reservoir to drop on the Ferris fire burning northwest of Dolores, Williams said.
Visibility is paramount for air attack planes. The Cessna that Lemmon flies features a tight cockpit and wings that sit below the windows, offering a good view. Some airplanes have wings above the windows, which is also good for visibility, but other models can present line of sight challenges.
In addition to the Durango base, there is a larger base in Colorado Springs that opened in 2022, and a base in Grand Junction, which recently underwent renovations thanks to a $9 million grant from the Great American Outdoors Act.