(first posted 7/23/2017) “Knee-high by the Forth of July” is a saying that’s become obsolete out here in the Middle West, the heart of corn and soybean country in the USA. In fact, the corn’s usually pushing 6′ tall (1.8m) by July 4, and will often exceed 12′ (3.6m) in height at maturity. The more common saying these days (taken from the musical Oklahoma!) is “High as an elephant’s eye by the Forth of July.”
Technological improvements in agriculture have enabled much higher productivity over the past 70-80 years, with average corn yields in the US increasing from around 30 bushels/acre prior to the 1940s to 140 bushels/acre and even higher today (a farming friend is disappointed if he doesn’t get “200 bushel corn” off our excellent soil here in Illinois).
One of the tools a farmer uses to maximize yields is aerial application of herbicides, insecticides and fungicides, and this is a common sight around here in July and August as the corn has gotten too tall for ground-based sprayers. These aircraft are often referred to as ‘crop dusters,’ but that’s not accurate, as the product they apply these days is in liquid form.
I’d be remiss to not acknowledge the controversy over the use of chemicals in farming – personally, we use organic methods ourselves on our small farm, but I also recognize that large-scale grain and bean production wouldn’t be feasible without it. There are plenty of other forums out there if you’d like to debate that, so we’ll stick to the aircraft itself from here out.
The first documented aerial application happened in 1906, when a tethered hot-air balloon was used to sow seeds. The first heavier-than-air application of pesticide occurred in 1921, when a Curtiss JN-6 “Super Jenny” was used to apply lead arsenate dust on catalpa trees in Ohio to kill sphinx moth larvae. Deeming the experiment a success, Curtiss biplanes were again used to dust cotton fields near Tallulah, LA in 1922 for the control of boll-weevils. A year later, Huff-Daland Dusters, Inc. (eventually to become Delta Airlines) began offering aerial application services on a commercial basis. Unmanned aircraft like the Yamaha R-MAX remote-control helicopter are beginning to see use for spot aerial application today as the technology continues to improve.
On the cutting edge of technology are electrostatic spray systems (photo is of a ground-based system), which set up a magnetic field over the crop canopy, and the aircraft spray booms are configured with one wing’s boom having a negative charge and the other a positive charge. This is very similar to modern auto paint systems which use a similar technique to ensure thorough and even paint coverage, even in the nooks and crannies of a vehicle as it moves through the paint booth. Electrostatic spray systems are currently very expensive, but as they use roughly ⅓ the volume of spray, with substantially higher effectivity, they will certainly become more widespread in the future.
Most of the fixed-wing aircraft used for aerial application today are turboprop-powered, but one of our local applicators still operates our subject 1967 Aero Commander S-2D, powered by a Pratt & Whitney R1340 “Wasp” nine-cylinder radial engine of 1,340 c.i.d. (21.95l) displacement. Depending on which variant it is, it likely produces between 500-600hp. The engine design dates back to the 1920s and was used on aircraft such as the Ford Tri-motor, Lockheed Vega, and the North American T6 trainer. It has a very distinctive sound, so I always know when to run outside to grab photos. The S-2D can carry 400 gallons (1,514l) of product (enough to cover upwards of 200 acres), and modern GPS guidance systems can achieve 6″ accuracy on the spray pattern, which has helped dramatically reduce the number of spray drift complaints in recent years.
The Aero Commander has an interesting history, as its parent company and name have changed a number of times. LeLand Snow designed his first purpose-built crop duster in 1953 and called it the S-1, using it as his own personal aircraft for hire. A refined version called the S-2 was built around 1956, and Snow began manufacturing them for interested pilots in the area. Despite having two aircraft completed and orders for 39 more, Snow was financially strapped and needed capital to continue. After talking with city representatives and local businessmen in Olney, Texas, the townsfolk put up the cash he needed to continue, which in turn gave their town a boost in the middle of difficulties resulting from ranching and oil businesses being on the decline.
The bet made by the town paid off, and Snow produced over 370 aircraft through 1965 (by then called the Aero Commander), when he sold the business to Rockwell-Standard Corporation, staying on as General Manager at the Olney facility. The aircraft became known as the Rockwell Thrush Commander during this time, and was continually being improved. When Rockwell told Snow he would have to move to Albany, Georgia if he wanted to keep his job, he didn’t have to think long about his answer, and stayed in Texas, working on a new ag aircraft design that would become the Air Tractor.
Ayres Corporation acquired the production rights to the Aero Commander, along with the Albany facility in 1977 and produced the aircraft as the Ayres Thrush until filing for bankruptcy in 2001. The rights were subsequently sold to Thrush Aircraft, who still manufacture the aircraft today under the Thrush name in a number of specialized models.
Ag flying is demanding and fairly high risk – there have been two crashes (one fatal) in our area since we moved here 15 years ago. But it’s also one of the last old-school ‘stick and rudder’ forms of down-in-the-weeds flying one can legally do (often compared to flying a fighter jet), and I envy these pilots every summer as I enjoy my own private air show.
A very necessary but very hazardous proposition. A friend of mine left engineering to become a crop duster as it was much more lucrative. He came back within two years.
Not surprised. Engineers, by and large, are not “excitement junkies” A new pocket protector is big news. It was probably more fun than he could handle, regardless of the money.
Living in the heavily-populated East Coast, agricultural equipment is one aspect of the mechanized world about which I know practically nothing. During my 2- or 3-times-per-year visits to the rural Midwest, I often see fieldside equipment that bewilders me. Often times, I look up this equipment to learn its purpose, but crop dusters are one thing that I’ve never read about — so reading this was extremely interesting. For example, I never knew why crop dusters were called “dusters.”
The average corn grain yield chart was interesting too. It reminds me of a story my wife’s family told to me. They used to farm, and had two small farms in Mid Missouri — one 12 acres and one 40 acres. The 12-acre farm was so fertile that it produced greater overall yields than the 40 acres, but eventually it became surrounded by subdivisions. They sold it a while ago, and it now contains a few dozen houses. With good farmland facing that sort of fate, it’s a good thing that yields are going up.
Back to the Commander, it’s great to see a 50-year-old aircraft still being competitive in it’s field (no pun intended). It would be a like seeing a 1960s Mack R Series still hauling gravel. Pretty amazing. I definitely learned some new stuff today — thanks!
Aircraft have a much longer lifespan than cars and trucks. It’s much more expensive to introduce a new design or model, and there’s far fewer units sold to amortize the cost. So decades-old plane designs and individual units are common, and not exceptional, especially with smaller planes like these.
Because no one wants planes falling out of the sky, certification is a major obstacle to minor changes. Incremental and superficial improvements often aren’t worth the ruckus.
Drop by Coal Harbour airport in Vancouver and you’ll see several De Havilland Beaver floatplanes doing scheduled flights up and down the coast. They were built from 1947 to 1967 – check out the Art Deco controls.
Beautiful ! .
Form follows function .
-Nate
Terrific information for those of us who are not savvy. Thanks.
Ed writes: “It has a very distinctive sound, so I always know when to run outside …”
Here in the crowded Northeast hearing a radial is a rare occurrence.
I do look up when I hear the distinctive sound of a Piaggio P.180 Avanti that seems to come and go from nearby Morristown Airport (NJ). That same sound used to come from the low aspect ratio Beechcraft Starship, but alas I think most have been returned to Beech for use as parts for those few survivors.
My latest “look up” sound now comes from military Ospreys that fly over my home in twos and threes. The have a rather unique sound, like helicopters, but not quite.
Thank you the information on modern crop “dusting”. The experts are telling us to eat more veggies, so this helps.
And, perhaps a movie quote is a good way to end this reply: “That’s funny… that plane’s dusting crops where there ain’t no crops!”
I heard, then saw, a Starship overfly our apartment in Norcross, Georgia some years ago. It was a hauntingly beautiful sound.
If you still live in the Norcross area, there is one at PDK that has been there for about 2 months and it flys pretty frequently. I had to look it up after hearing it take off for the first time.
We’ve been away for over 15 years, but the one I saw was almost certainly inbound for PDK. I was based at LZU (part owner in a Cessna 172).
Yes, the Ospreys do indeed have a unique- and extremely LOUD- sound. A couple months ago President Trump made a visit to Snap-On Tools World Headquarters, which is about a half mile from my house. Three Ospreys made a trial landing there on the Saturday before his visit. They came over my house at very low altitude; the whole house shook!
For those who may not have heard one (close up), the Piaggio Avanti’s distinctive (external) noise signature is because the props of its two turbine enginines are in the pusher position, one behind each wing.
This means they’re operating in a much more disturbed airflow than normally located props. This unscientifically speaking, adds a much more tearing / rasping tone to the prop noise. And has, supposedly, led to attempts to ban them at some airports – I’m not sure with what outcomes.
Very good and informative article .
My middle Brother is a Flier, he also like acrobatic Gliders and managed a deal on a used crop duster to use as a tug to get his Glider Club’s gliders up .
It has this HUGE engine but since the removal of the tank, pump and sprayers, it has lots of excess power and goes like stink .
If ever you get the opportunity to fly in a small aircraft, GRAB IT .
When I travel in Central Cali. I occasionally run across some crop duster getting ready to fly his biplane with radial engine, I always stop to listen .
-Nate
“Knee High by The Fourth of July” is accurate in Maine. Planting before Memorial Day has risks of frost. Very interesting article.
I used to see a lot of crop spray aeroplanes operating in cotton country in western NSW they fly below the channel banks under the power lines and often at night when its cooler guided by a Suzuki Jimny with a flashing light at either end of the cotton paddock, they used air trucks specially designed for this sort of activity with wings resembling a Stuka dive bomber crashes did happen but not frequently most pilots and ground guidance crew quit due to chemical poisoning not crashes.
iirc, Grumman made a cropduster for years. Following Grumman’s naming convention, it was dubbed the “Ag-Cat”
There are probably still scores of Stearmans out there doing the same job.
Those of us who saw “Mad Max, Beyond Thunderdome” may recall the bizarre airplane that appeared in a couple scenes. It was an Aussie built cropduster, the Transavia PL-12.
I wonder if that or a similar model is the one I saw maybe 25-30 years ago. I do remember that it had a 454 Chev engine (possibly aftermarket alloy block/heads)
The one in the film appears to have a Continental flat six. I have never seen such a comic-looking thing, as if from a Pixar film.
Thats not it but similar they didnt dump chemicals or fert like a Fletcher top dressing plane they had spray heads along the wings, I probably have the name mixed up, similar planes were used on tomato crops in NQLD We only saw them in the dark early mornings on the cotton while waiting to start work at first light it was illegal to spray when humans were about.
That would be fun to watch.
When I hear radial engines around my house it’s usually a B-25 or a Harvard (T-6 Texan)
The usual maker of “look up” sounds at my home is “Yankee Lady”. She is owned by a museum at Willow Run, which is a about 10 miles from my home. If Paul works his way back here in maybe 5 years, we can stop buy the museum, which should be settled into it’s new home: the remaining hanger section of the Ford B-24 plant at Willow Run.
I have 3/10 hour in my log book in the EAA’s Aluminum Overcast B-17G (from back in the late 1990s when you could still sit left seat and log your trip – nowadays you only get to ride in the back).
I heard, then ran outside to see it flying right over the farm a few years ago, which was super-cool.
The annual Stearman Fly-in is held about an hour from us in Galesburg, IL, and I enjoy seeing them fly over all week, often in multi-ship formations.
B-17 simply glorious polished up like that. Is it the lack of military colour, the boyhood toy associations (hard to believe real folks were ever in those bubbles), is it a hangover of the lack of consequential insight from then (rat-a-tat, crash, burn, repeat through the living room doorway, noises spitting from mouth), is it innocence or am I wilfully discarding the true role of this bird as a killing mechanism, simply because the aesthetics and the sounds and WW2 “Flying Fortress” associations are overaweing? Often ponder this conundrum with military hardware of all sorts, without coming near to an answer. Then, just spent 10 mins after the video showing my youngest son footage of the Harrier jump jet doing its’ unnerving calisthenics. Exciting, and, like a ghoul arising, frightening too.
Most jealous of your B-17 flights, Mr Stembridge.
B-17 simply glorious polished up like that. Is it the lack of military colour,
iirc, once the allies had air superiority over Germany, they stopped using the heavy camo paint on the planes. It saved weight, which could be redeployed to increase bomb or gas load.
…am I wilfully discarding the true role of this bird as a killing mechanism,
I think most people understood why the 17s were doing what they were doing. What the Germans did to themselves in the 30s was one thing. When they overran most of the rest of Europe and started imposing their theories of eugenics on everyone else, it became everyone else’s business. I had a school teacher in the 60s who was a teenager in the Netherlands during the occupation. He talked about the fear whenever a German was near as they always gave him a fishy look due to his black hair. One day, he was with two friends when some German soldiers came after them. They ran. The Germans caught one of his friends. He never saw that friend again.
Most jealous of your B-17 flights, Mr Stembridge.
You can’t get any stick time on “Yankee Lady”, but you can go for a ride. The museum put together this promo film.
My dad has lived his good Catholic father-of-six life from age 5 here at the other end of the world from his birthplace in Berlin, a place he fled in 1939 because his WW1 war hero dad was considered Jewish. I have very personal reasons to be thankful Hitler was defeated (in which process Australians played significant roles in the air). I am not, for many reasons, going to enter the minefield of “what the Germans did to themselves” vs “totalitarian domination of a nation”, not least of which is my background – my surname itself is a German word, after all. My pondering has nothing to do with whether a machine ended up on the “right” side of history but more a nagging discomfort over admiration for any machine whose purpose is, one way or another, to cause death. Call it Catholic Jewish guilt, the one with the lot.
As I can’t fly a plane, I’d be happy to be a dreaming passenger on the Lady one day.
PZL in Poland produces Dromader plane which originates in Commander licence. Also in PZL produces strangest agricultural plane ever – Belphegor – a jet biplane. Story about that: I once read that Polish representative of aero industry goes to Moscow (according to plans Poland should produced agricultural planes for whole “east block”) with plans of modern planes but throw them away to toadying for Russians – which at the time didn’t even thought about designing agricultural planes. Except one engineer which name I don’t remember who should rather write Sci_Fi novels than designing anything.
When I was flight training back in the late 1990s, I made a solo cross-country flight from Atlanta, GA to Valdosta, which happens to be where Charles Lindbergh taught himself how to fly in a surplus Curtiss Jenny.
Lined up along the runway were dozens of Polish crop spraying aircraft, in various states of disrepair. I asked about them at the FBO office and they said a group of investors had bought and imported them, only to find out the cost to certify them was essentially going to bankrupt them. IIRC, the engines were of a make and type that was already certified, so they sold those and left the airframes to rot.
The story I had read about the PZL M-15 Belphegor is that it was designed to replace the Antonov 2 (also a biplane). The biplane configuration provided the necessary lift for the specified load whereas a monoplane would have had a longer wingspan. Jet fuel is less expensive than aviation gas so a jet engine was used. The result was a unconventional and ungainly looking aircraft that unfortunately did not live up to its expected potential.
I recall a Piper Pawnee cropsuster that flew out of a local airport. Lots of power in a lightweight maneuverable plane is the name of that game.
I heard the music of some radial engines lumbering through the sky over my house. I believe it was a B-17 visiting for a few days. Unfortunately I didn’t get a glimpse.
There’s a golf course near our place that is beside a grass airfield. They use a Pawnee to tow the gliders up.
Normally I dislike golf, but having the Pawnee coast by 200 feet overhead every 10 minutes on it’s way to pick up another glider sure helps. 🙂
Our little local airport has a Texan, and a couple of Stearmans, so I get to hear that great radial sound once in a while.
The biplanes usually do a nice flyover for the beginning of our July 4th parade.
In the late 40s and early early 50s when modified Stearman PT 17s were the crop duster plane of choice , operators bought hundreds of Vultee BT13s from the war assets commission for a few hundred bucks each. They canibalized the P&W 985 to replace the Continental R670 on their Stearmans, thus greatly increasing performance and payload.
They also refitted the Vutee’s wider tires and better brakes. One article I read said it was not uncommon to see stripped Vultee airframes pushed off into the weeds around rural airports.
As a aviation enthusiast l’ve seen countless airobatic acts at numerous shows in the St Louis bistate area. Yet the one that left my jaw hanging open occurred this spring in the corn field near my house. The field is only a1/4 mile wide, trees on one side and a road with power lines on the other. These obstacles were perpendicular to flight path of a turbine ag spray plane. I’m driving down the road watching the plane make passes on this field on the deck at maybe 80 or more knots staight at the trees,snap to a near vertical climb ,rolled it over at about 150 agl for a near vertical dive in the opposite direction all within about the planes wing span. Near the power lines the incredible power of the turbine allowed him to climb and manuever with with very little forward airspeed.On the last pass he shot under the power lines and across the road 4or 500 ft ahead of me.then pulled up to clear the neighbors house and trees. I was like, did I really just flipping see that.
My brother is an A&P. Works on war birds too. Flys to air shows in them too. He calls me if their departure or in bound will pass over where I work. When ever I hear that reverberating sound in the sky I yell round engine and me and 1/2 dozen guys at work run outside.
Speaking of cropdusting, there’s a funny Jack Benny Program circa 1962 with guest star Raymond Burr.
https://www.youtube.com/watch?v=b5nn1RZe8Wc&t=1038s
Jack Benny and Raymond Burr does a funny skit where Burr is in charge of a group of motley cropdusting pilots and Benny plays an ambitious General of the cropdusting squadron.
But you gotta watch the beginning of the show to see how funny Raymond Burr can be, followed by Burr reeanacting a dramatic World War II Air Force scene (at 9:00) that sets the stage for the funny skit with Jack Benny (beginning at 14:20).
A few years back, I was on my way down to Rehoboth DE on Route 1 and there was a bit of a traffic jam below Dover AFB, which isn’t unusual on a trip to the beach, but this day, it was in a different area on the road. When we finally got to the source of the slowdown, what we saw was a similar sight to what Rich C describes above. Power lines on one side of the field, trees on the other, and a very skilled pilot flying what looked to be a very modern biplane (something like a Pitts) spraying this field of soybeans I think. What a show! Although I’m an aviation buff, I don’t know my crop dusters (other than the aforementioned Curtis Jenny ;o), or I’d ID the plane for you.
As to radial engines, yeah… whenever you hear one, you HAVE to look up. Around here, whenever I hear this sound, most of the time it’s either an AT-6 or some other old warbird or trainer flying into Glen L. Martin Airport (KMTN) in eastern Baltimore County, or a guy who flies his Stearman out of Harford County (0W3) tooling around. Back in 2004, I got the pleasure of hearing the latter’s 7-jug Continental up close and personal, when I got about 35 minutes of stick time, albeit from the front hole, on an hour long flight in this bird….
Electric Field, not Magnetic…
Was quoting from the web site of the company that makes the system – magnetic was their word, not mine…
Not sure what company you looked at, but I googled aerial electrostatic spray to see what came up. As I understand it the spray nozzle puts an electrostatic charge on the spray droplets. So either electrons are taken off or put on. Since charge must be conserved, it makes sense to take the electrons off of the spray on one wing and deposit it on the spray of the other wing.
Found it: http://spectrumsprayer.com/news_1.html
“A big reason for the increase in production efficiency of today’s aerial applicators is a technology 25 years in the making by engineers at Texas A&M University. Spectrum Electrostatic Spray Systems set up a magnetic field over the crop canopy with negative charged spray particles jettisoned from one side of the 60-foot boom beneath the plane’s wing, and positive charged particles from the opposite portion of the boom.”
I read the article, but I think that the magnetic field is more advertising hype than reality, although it is true that moving charged particles create a magnetic field. The charge on the spray droplets will enhance their effectiveness.
The 1906 hot air balloon caught my attention. One of the early reports of “UFOs” was a blimp-like vehicle seen over a Texas cattle ranch in 1895. Maybe it was just a crop duster, unadvertised and thus unexpected.
Very interesting article. I live in the Midwest corn country, and see planes doing this fairly often at certain times of the year. Great fun to watch.
We live near the Orange (Massachusetts) Municipal Airport (KORE on your Sectional) which has the advantages of being quite rural while simultaneously having an uncharacteristically long main runway – nearly a mile. We have the privilege of having several “round-engine” aircraft which frequent our airspace: a Stearman, a WACO, and an occasional visit from a Beech Staggerwing that used to be home-based in Vermont though not seen recently. My wife and I are magnetically drawn to the window, or better still outdoors, to scan the sky for air traffic when we hear the distinctive sound of a radial aircraft engine. We love air traffic in general, but round engines are best as well as being a nostalgic sound from my past. We don’t have cropdusters here, but we’ve got some real classics around here. In fact not more than a few hours ago, a pre-war biplane lazily flew over, silhouetted against the bright afternoon sky. It don’t git much better’n that!!
Perhaps they were on their way to or from OSH… We have aerial applicators in Middle TN (where we moved after I retired), but fields are much smaller here than in the Middle West, and our area is fairly heavily wooded, so I hear them more than see them. There’s an ANG station in the vicinity, so I’m more likely to see Chinooks on refueling training flights these days.
Back in my banner towing days I was looking for a larger more powerful airplane to pull a large sky sign a customer wanted. One of the aircraft I looked at was a 1959 Snow S2C. That one had a R985 at 450HP and we were within $500 of a deal. I passed and never bought a bigger plane than the ones I was flying.
A few years later I found out a tow operator in Ocean City acquired it and one of the pilots ran it off the runway.
Interesting ~
My idiot middle brother is a glider fanatic and belongs to a glider club Down East, they needed a tug to get them aloft and he found a sweet deal on an old crop duster ~ after removing the HUGE tank, pump and sprayers it was so powerful it never noticed the weight of gliders being towed .
This is my goofball brother who parked a glider in a tree once and owns a Mooney aerobatic monoplane .
-Nate