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Jacks of All Trade; How Cropdusting Stopped Being Limited to Dusting Crops

You can throw the word cropduster at anyone and they will know what you are referring to; However, depending on their level of agricultural exposure, they may come to think of the latest and greatest Air Tractors hauling sophisticated pesticides, or they may recall the famous scene in North By Northwest where the biplane bears down on Cary Grant's character. They might think of the aircraft or the pilots operating such machines, which truly defines the relationship between both with such interchangeability. Both are accurate in their own way, and although either mental pictures help define the term, they don't really explain its origin.

Lt. John A. Macready and his groundbreaking Super Jenny

In 1921, Lt. John. A. Macready and his modified Curtiss JN-6 Super Jenny applied lead arsenate dust over catalpa trees under the close supervision of the Ohio Department of Agriculture. The trial proved successful and the government pursued the endeavor by creating a small fleet of customized Curtiss biplanes to dust the cotton fields of the Southern states. In 1923, the first commercial dusting of crops took place, by no other then Huff-Daland Dusters Inc... the precursor to Delta Airlines!

So here we have it; the simple etymology of a well-known word born in recent history. Even though we have since mostly moved away from applying dry dusts and mostly rely on liquid solutions for aerial applications, the old title stays, and with it the pioneering spirit of those first flying farmers.

Along with the endearing old-timey feeling of the title, however, comes a darker side. Aerial applicators are often burdened with the facts of the past. Some will look at the plane and pilot combo and picture dealers of death: a symptom of having dealt with extremely volatile chemicals that were since discovered to have dangerous environmental consequences. The most famous chemical in our part of the world likely being dichlorodiphenyltrichloroethane... more commonly know as DDT. Though the product was discovered in the late 1800s, its use was popularized during the era of the Second World War as it was hailed as a miracle-cure for fighting the spruce budworm infestation in Ontario's forests.

'Budworm City' was established in the early 1950s near Upsalquitch Lake and used as a base for DDT spray operations in northern New Brunswick. (D.C. Anderson.)

Though DDT might only bring to mind the lyrics to a Joni Mitchell song for some (or the Counting Crows depending on which generation you hail from-), it received the public's attention after a number of potential symptoms were linked to the levels of DDT found in human and animal bodies. Unfortunately, due to the wide varying spectrum of symptoms and the incredible persistence of the product in the environment, combating the residual effects is a not only a complicated endeavor, but a very long, ongoing battle. Despite DDT getting banned in Canada back in 1985, with its last recorded use in 1990- there are still remnants of the product in the environment today.

Protesters at Bayer's Berkeley campus, protesting the production of neonics

This is not a single one-off situation either, the current hot topic of conversation is the use of neonicotinoid pesticides (often referred to as neonics) in Canada. What raised the red flag for neonics was a high level of incidents involving pollinators. Though this has been significantly reduced with implemented mitigation techniques, the study is ongoing and I expect further restrictions will be put in place before a total ban is considered.

I share this unfortunate history, not to perpetuate the idea that aerial applicators are poison-pushers, but to highlight that research is ongoing, that chemical technology is continually improved upon and that we are becoming more environmentally conscious as the years go by. We must acknowledge the lessons of the past to ensure we move away from the damaging practices and move to more sustainable systems.

For example, the war against the spruce budworm and gypsy moth caterpillars is ongoing in Eastern Canada, but the chemical of choice these days is the organically certified bacillus thuringiensis subspecies kurstaki (Btk); this bacterium naturally found in soil produces a protein crystal during the spore-forming stage of its life-cycle. These crystals, once ingested by the target pest, destroy the walls of the larvae's stomach due to its alkalinity, causing death within 3-5 days. The beauty of this product is its effectiveness is only against lepidopteran insects (i.e. the aforementioned invasive pests!) and its general harmlessness against not only humans, but mammals, microorganisms, and the environment!

Forestry work, spraying Btk against the spruce budworm infestation in Eastern Canada

Chemical use is always a hot-topic for discussion and nearly always the reason for bad light to be shined on our profession, so rather then continue down the avenue of well-rehearsed debate and rehash the need for responsible pesticide use, I rather share with you the other facets of the industry that stole my heart.

What else do aerial applicators do, other then apply pesticides?

Having grown from the title of cropduster to aerial applicator, the name change alone seems to imply a broadened spectrum of ability. So what else do aerial applicators do other than dust crops as cropdusters did? (Try saying that 3 times fast!)

Aerial Seeding

Something that always brings me much joy is sharing the fact that aerial applicators can also bring life to an area! This is usually separated into two different categories; cover crop and forestry.

This aerial seeding practice was started in New-Zealand in the 1930's, by a man called Alan Prichard. Inspired by his tossing out grape seeds out of the open cockpit, he invented aerial seeding in the difficult mountainous terrain of the country with the use of a Miles M.11 Whitney Straight. The dispersal system, a simple seed-sack and a chunk of downpipe, the first hopper and spreader combo! The fields seeding in those personal tests ended up being indistinguishable from hand-sewn fields. The rest is history!

Loading cover crop seed into the hopper of the Ag-Cat for aerial seeding.

But what is cover crop, specifically?

The concept of cover crop is to keep fields covered; the conventional practice involves planting a crop following a harvest. The advantage of aerial seeding is the ability to get a crop started BEFORE the harvest of the previous crop has taken place. For example, consider this rye planted within a thriving corn field;

Rye cover crop planted via aerial seeding within corn.

The purpose of intermingling such crops and the boons of cover crop are less about being able to harvest another commodity and more about preserving and improving soil quality! Well-planned cover crop can help the soil in a myriad of ways, such as reduce erosion, conserve soil moisture, suppress weed growth (reducing the need for herbicides) but most importantly, it can add nutrients to the soil, such as nitrogen, reducing the need for fertilizing and it is also preventative in the face of nutrient leaching. Of course, there is also the possibility of the cover crop in question being used as grazing/pasture, silage, etc!

Piper Super Cub used in forestry seeding. Note the dispersal system beneath the aircraft behind the main landing gear.

In the realm of forestry, aerial seeding is used for reforestation. When lumber is harvested and woodlots decimated, aerial seeding is often an ideal means of replanting remote locations. For example, in Northern Ontario, it is not uncommon to use aircraft to replant previously harvested land, plantations with poor success rates, where soil is too thin to plant by hand, or even forest-fire devastated areas.

Typical forestry seeding block; note the scarification lines from prior cultivation

The seeds of choice tend to be jackpines, black and white spruce, even white pine. When using aerial seeding, the areas will often be monitored for growth and in 10-15 years, mechanical means will be used to clear brush and give the saplings the best conditions to thrive in. Already nearly 100 years old, the practice is now well-developed well-researched. It is also not limited to fixed-wing operations but involves rotary too! It is a wonderful way to help repopulate our forests.

Lake Restocking

In headlines that never cease to make me smile, you see folks stunned to see plane-loads of fish being dumped into various lakes. Though every time this situation is shared by the media, everyone seems to think it is a new thing. The reality is that stocking lakes is a very old practice that used to involve barrels on horseback!

A load of young trout being stocked by air into a lake in Utah

However, not all lakes are accessible by road, so what better job for a quick, hopper-equipped aircraft to do then replenish the local fish population? Following the recommendation of marine biologists and other relevant experts who monitor local fish populations and the conditions of the lakes, hatchery-born fingerling or yearling fish are loaded into the tanks of spray aircraft and subsequently dumped from the emergency/fire gate. Despite falling from altitudes of 50-100 feet, the fish have a tremendous survival rate (although, I certainly bet they are a little confused!)


New-Zealand, 1953, a repurposed Tiger Moth getting loaded with fertilizer for topdressing.

Topdressing is an ancient practice, simply with the option to be done with very modern equipment. To top-dress means the application of something without working or mixing it in. So when topdressing soil, it is adding manure, compost, or other material layered on top of the soil. When speaking of aerial applicators, this usually refers to the practice of applying fertilizers. We once again have the aforementioned Alan Prichard to thank for this development, as he added fertilizer to his seeding trials from 1939-1943. However, the first commercial aerial topdressing did not take place until 1949.

Modern Turbo Thrush, and Ag-Cat, fitted with dry material spreaders for topdressing or seeding.

Currently, the most common practice for topdressing either involves adding liquid fertilizers to pesticide solutions, such as fungicides or insecticides that were prescribed for application, or the application of NPK (nitrogen, phosphorous, and potassium) granules with a dry material spreader. The advantage of aircraft in this case, much like cover crop seeding, is the ability to spread the granules or spray into tall crops such as corn, something that some ground-based equipment are unable to do. Salt-based granular fertilizers will sit atop the soil until ground moisture or rainfall comes to dissolve the granules and spread the nutrients into the topsoil. Granular and liquid formulations have different advantages.

Topdressing is a practice that takes place both in agricultural and forestry projects!

Aerial Firefighting

The much more dramatic facets of aerial applications, and one of the most easily recognizable is our incredible aerial firefighters. This is one of the most diverse fleets in the aerial application world, from specialty-built machines, to custom retrofits, from single props to quad-engines to jets, from wheeled-aircraft to floatplanes to amphibious machines, as well as helicopters, of course; there are all kinds of flying machines in the air today to help combat devastating fires all around the world.

A DC-10 Air Tanker dropping a load of fire retardant

Aerial firefighting aircraft, often referred to as waterbombers or airtankers, have seen their budding beginnings as early as 1916, as ideas were thrown around and tested, from creating actual water-bombs made of wax-papered sacks or tossing water barrels à la Donkey Kong, most of these first endeavors were unsurprisingly abandoned, but paved the way for ongoing trials.

The year 1956 was an important year for the advancement of aerial firefighting techniques and trials as a raging fire season in California had the American government create Operation Firestop, which mobilized and modified many WWII-era surplus aircraft into a myriad ways in an attempt to fend off Mother Nature's anger.

Canadair CL-215

Canada's most important contribution came in 1966 with the decision to move into production of the aircraft that became known as the Canadair CL-215; the only dedicated waterbombing aircraft designed at the time. The first CL-215 flew in 1967 and production was continued for 33 years, creating a world-wide based fleet of 125 firebombers. Albeit its difficult beginnings, the CL-215 is now considered quite the legendary aircraft, and since then, the lineage has continued with the Canadair (become Bombardier become Viking Air) CL-415, a turbine powered amphibious water bomber with a full EFIS avionics suite.

Viking CL-415 dropping a load of water

Air tankers can drop water, water enhancers (foams or gels) as well as specially formulated fire retardants. Some will be onloaded at their airport bases, whereas amphibious machine such as the CL-215 can scoop up a load from natural bodies of water! Though most firefighting aircraft use a fire gate installed in the belly of fuselage, some helicopters use bucket systems such as the Bambi Bucket!

Firebomber dropping water on vehicle accident on remote Labrador highway

Although firebombers are usually deployed onto raging forest fires, turf fires or field fires for quick action, they have also been called in to act upon vehicle fires in remote locations, especially agricultural equipment in the fields.

Aerial firefighting is an incredible way to reach the target in an expeditious manner, limit the devastation, and helps create a fireline around the flames, to buy time so that the crews on the ground can encircle the area with firebreaks. Contrary to popular beliefs, the goal is rarely to completely extinguish the fire but typically to support ground operations in holding the line or protect assets or property.

A firefighting helicopter equipped with a Bambi Bucket assisting ground crews.

It takes a special courage to fly towards an inferno, in the heat, the turbulence, and the obscurity of the billowing smoke.

Whatever the future may hold

Though many still affectionally use the term cropduster, the career of the modern-day aerial applicator has evolved in so many ways; from the latest in aeronautical engineering with the new generation of spray-planes and firebombers, to the complexities of chemical technology and its eco-conscious turn in development, to the safety-oriented mentality of operators and crew members today. What the future holds likely will continue around the trend of improving dispersal technology to minimize instances of spray drift, less volatile yet increasingly effective chemical technology, and more safety features to protect our low-flying brethren, as well as better aircraft performance.

Unmanned aerial vehicle (drone) for crop spraying

However, the newest contender in the field are unmanned aerial vehicles (drones). Removing the pilot and the potential endangerment of human life in these fast paced and highly complex environments while being able to more specifically target pests are the possibilities appearing on the horizon. Drone technology has developed by leaps and bounds in the last few years and I anticipate that it will continue to do so as well as develop its commercial potential in every industry.

Despite the incredible rate that technology evolves, I do not believe manned aircraft will be retired in my lifetime.

However, just in case, I'll be sure to enjoy my time in the seat of my workhorse.

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