The Eastern Plains of Colorado, divided by the South Platte River and Arkansas River valleys and backdropped by the Rocky Mountains, is one of the more scenic places in the United States. At an average elevation of almost a mile, the density altitude climbs rapidly in the summer. The “high” and “hot” adage, however, is routine for Air Dusters, Inc., a third-generation operation in the small town of Roggen, about 40 miles northeast of Denver.

Air Dusters, Inc was founded in 1952 by Carl Schellenberg and Al Williams. Both pioneers in the ag aviation industry, Al, who was a P51 pilot, did the majority of the flying while Carl, an A&P/IA, ran the day to day operations and maintenance. The pair operated three 450 HP Stearmans purchased after the second World War. The two were great business partners, but even more, they were great friends.

In 1959, Al Williams tragically lost his life in one of the Stearmans. Carl Schellenberg struggled, but bought the business and kept two of the Stearmans flying; hiring a pilot so he could continue to focus on the day to day operations. He continued to run two Stearmans, treating mostly wheat, barley, sugar beets and some corn. During that time, the aircraft were treating about one-third of their total acreage with dust and the remaining with liquid applications. In the early 1960s, Carl brought both of his sons on board as flaggers (at age 8!), Chris and Dan. Carl taught both boys to fly. Chris began spraying in the early 1970s with Dan following shortly thereafter.

Carl’s son, Chris, suffered a fatal collision with power lines in 1987. This event rocked the Schellenberg family and the entire community. Chris’s accident left Air Dusters with one aircraft, which was one of the original Stearmans purchased by Carl and Al in the late 1950s. A local operator stepped up to help Carl and Dan make it through the rest of the season. Carl realized he needed to move the business forward from the Stearmans and enlisted the help of Air Tractor’s Leland Snow and dealer Lane Aviation. Carl purchased serial number 17 AT-502 with a PT6A-34AG. Many 502s of that vintage were powered by PT6A-15AGs, but due to the elevation, Carl opted for the PT6A-34AG configuration.

Dan Schellenberg started flying the AT-502 and admits it took him quite some time to adapt from the lesser performing 450 HP Stearman, which the Schellenbergs sold after the Air Tractor acquisition. This transitioned Air Dusters Inc. back into a one plane operation until Dan’s son, Jason, could begin flying.

Air Dusters’ AT-502 has just taken on a load and is about to taxi behind the company’s AT-402A for a formation photo shoot.

Carl Schellenberg passed away in 2011 after over 50 years operating Air Dusters, Inc. Carl was involved with the flying service until his last days and witnessed the beginnings with 450 HP Stearmans to the technologically advanced Air Tractors.

Jason Schellenberg started his flying career at an early age. Instructed by his dad, Dan. Jason soloed at 16 and then immediately earned his private and commercial licenses by 18. HIs first season was in 2005 in a Weatherly 620B. Jason flew the Weatherly for seven seasons and during that time had to execute several forced landings. With Carl’s help, Jason earned his Airframe and Powerplant mechanic ratings in 2010. Jason went on to earn his IA rating in 2019. “I know my gramps [Carl] would be proud,” comments Jason.

In 2012, Dan and Jason decided to sell the Weatherly and upgrade to a 2001 AT-402A powered by a PT6A-11AG.

Air Dusters Inc.’s typical season runs from April through October. April brings traditional herbicide on wheat and insecticides on alfalfa. They transition to more fungicide applications as the year progresses and have quite an intense “Sunflower Run” to battle the head moth and seed weevil. For sunflowers, applications need to be made as soon as the flower opens.

An unusual amount of Air Dusters’ applications are made inside the KDEN (Denver International Airport) Class B airspace within a stone’s throw of the runways. “Until a few years ago when I started, I never realized how challenging flying within DIA’s airspace could be until I had to do it, with its many power transmission lines, multiple active runways and trying to get in a word ‘edgewise’ at the fifth busiest airport in the U.S. My dad has sprayed close to a couple hundred thousand acres there and never once complained to me about it! It sure keeps you on your toes, that’s for sure,” says Jason.

(L-R) The Schellenberg family: Dan and Cindy and Jason and wife Shelly, with the Schellenberg kids Cael, Braden, and Carly.

Air Dusters’ ground crews are seasonal, but the rest of the operation is all in the family. Dan’s wife (and Jason’s mom), Cindy, handled the accounting for Air Dusters for many years. Cindy’s daughter, Stacy, took over for her around 2007. Stacy’s son Harley is working on the ground helping keep the airplanes flying.

Both aircraft, the AT-502 and the AT-402A, are outfitted with SATLOC Bantam GPSs and CP Products CP-11 nozzles. The AT-402A is also outfitted with the new AFS carbon fiber coated aluminum booms and check valves made from Celcon (semi-crystaline thermoplastic). The booms have a black fiber carbon coating on the inside and outside. This is supposed to extend the life of the booms and eliminate corrosion problems.

“We went with the AFS carbon fiber coated booms because our aluminum hardware was corroding and leading to plugging our nozzles, especially with our low volume herbicide applications. Although we use a stainless steel pump, we wanted to give the lighter AFS booms a try and see if that would solve our problems. So far, all good,” reports Jason. “We run low volume applications for herbicide whenever we can. My uncle and dad stumbled upon realizing that low volume herbicide worked much better than high gallonage applications.”


The AT-402A is also outfitted with the new AFS carbon fiber coated aluminum booms and check valves made from Celcon (semi-crystaline thermoplastic). The booms have a black fiber carbon coating on the inside and outside. This is supposed to extend the life of the booms and eliminate corrosion problems

Today’s workload is 100% liquid. The aircraft operate off a 2,500-foot runway at 5,000’ MSL. Dan and Jason have conditioned themselves for this type of flying. Generally, they reduce the load when the outside air temp reaches about 80°F.

Jason is a state director with the Colorado Agricultural Aviation Association. Dan and Jason are members of the National Agricultural Aviation Association, too. Jason and his wife, Shelly, have three children, Carly, Cael, and Braden,  who all have an interest in aviation and farming and someday may continue the legacy of their great grandfather. Jason graduated from the Leadership Training Program in 2019 and plans to continue with his involvement in the state and national associations advocating for the industry.

Working day in and day out at high elevations are sure to give some ag pilots pause. Unless a pilot has flown from higher elevations, it would be difficult to understand the challenges flying at higher elevations can bring, from longer take offs and landing rolls, to more gentle turns when loaded. From the early days of ag aviation in the late 1950s when Carl Schellenberg was fighting the Stearmans to get off the ground, to today when Dan and Jason are letting the turboprop Air Tractors do what they do best, making operating “hot and high” just another day at the office.




Jason Schellenberg patiently waiting for the hopper to fill in the AT-402A.


There may not be any mountains in sight in this photo, but be assured that the field elevation is 5,000 MSL and that requires plenty of experience to fly “high and hot”.


Dan and Jason approach the airstrip for a formation landing in the Air Dusters’ Air Tractors.


Jason Schellenberg