FRESH FEATHERS: The birdman of Argyle breathes new life -- and a dose of steroids -- into weary ag birds

ARGYLE, Minn. -- The sight of a banged-up Thrush S2R ag plane sitting unused at an Arkansas airstrip may not stir up any emotion in most people, but to Lindley Johnson's eyes, it is a bird that can take to the skies again, faster and more reliabl...

ARGYLE, Minn. -- The sight of a banged-up Thrush S2R ag plane sitting unused at an Arkansas airstrip may not stir up any emotion in most people, but to Lindley Johnson's eyes, it is a bird that can take to the skies again, faster and more reliably than ever.

He is the owner and president of Johnson Airspray Inc., a small but successful family firm near Argyle, Minn., that takes worn-out or banged-up ag planes and completely refurbishes them, hangs freshly overhauled Walters turbines on their beaks and then sells them for about half the price of a new one.

They call their planes "Walters conversions,"

but to the ag-flying public, they are known as "Johnson conversions." The planes spray crops throughout the Red River Valley, various states of the Union, and even in Australia.

Lindley Johnson began flying as an aerial applicator in 1959. In 1973, he partnered with aircraft mechanic Rodney Peterson, and they began buying used two-seat Bell helicopters to convert into ag sprayer platforms.


"We bought them military surplus and then built them up," Johnson says. "They were just the small ones like the G3B1s" bubble-canopied helicopters.

They sold these to spray outfits until 1984, when Johnson bought Peterson out and renamed the outfit Johnson Airspray Inc.

Today, with Johnson children and grandchildren working at Johnson Airspray and Argyle Chemical, another of his businesses, he's a busy man. Among his offspring are ag pilots, plant managers, chemical loaders and one plane fabricator, his granddaughter, Chelsey, whom he calls "Rosie the Riveter."


In the early 1990s, Johnson decided on a major engine upgrade, called a "re-power," for his own spray plane.

"We got tired of the radial engines quitting, so we decided to go to turbines," he says.

The turbines that are available in the United States, such as the Pratt & Whitney, would sell for around $400,000, he says. The Walters, made in the Czech Republic, has a long-lived and sound reputation.

"Walters has been building since 1911," Johnson says. "You know, they were a Communist nation before, and they used to build the MiGs that flew in Korea."


Johnson has since used them to re-power several other aerial applicators' aircraft as well as his own five-plane spray squadron, based in Argyle and Grafton, N.D.

Turbines basically are jet engines that turn propellers. Planes with these engines are commonly referred to as "turbo-prop" aircraft. Their power plants have far fewer moving parts and therefore are more reliable and require less maintenance than the old radial piston engines, which have not been manufactured for several decades.

In aircraft engines, especially those in ground-hugging ag aircraft, reliability equates to the safety of the pilot, a key selling point for the Walters conversions.

Another is maintenance intervals. An aircraft engine's age is gauged by operating hours instead of miles driven. The Federal Aviation Administration has strict requirements for the number of hours an aircraft engine can run before

it must be pulled from the plane and completely torn down and overhauled. This is an expensive proposition for any flier, including Johnson, so the longer

an engine can go between overhauls, the better. A radial engine requires rebuild every 1,000 to 1,200 hours.

"With a turbine, we have to start doing something with them at about 2,500 hours," Johnson says. "So you're doubling the life. Of course, the overall costs are more for the turbine than they are for the radial, but the radials are getting spendy also."

A Walters turbine overhaul runs about $100,000, while a radial overhaul runs nearer $40,000, he says.


The Walters turbine also turns out more than 650 horsepower, a valuable commodity to ag pilots when they have to haul back on the stick to clear the trees at the edge of a field.

"You can use the whole seat, you don't have to sit on the edge," he says, laughing. "You don't have to work to keep the airplane up in the air. You're not fighting the airplane, and so you're a lot more relaxed and you don't get as fatigued."

Johnson either sells the old engine as is or has it overhauled and then sells it. To do the engine conversions on ag planes, Johnson had to get a Supplementary Type Certificate approved by the FAA. The engine itself already was an FAA-approved power plant, but the installation onto ag planes also had to be approved. Johnson now is certified to install Walter turbines on Thrushes, Air Tractors and Ag Cats, and Johnson Airspray is a certified installation center for the Walters turbines.

New feathers

When the Johnson team isn't doing re-powers on clients' planes, they keep themselves busy with whole-plane refurbishments.

They start with a worn-out ag plane, such as an old Ag Tractor 301. It may have a slightly bent section of frame from a rough landing or just a worn-out engine or controls.

"We'll take the airplane and strip it down completely to the frame," Johnson says.

The frames are made of lightweight tubing, which can be straightened or welded, as needed, up to a point. His operation currently has four airframes in various stages of rebuilding.


"If they're bent up too bad, or if they're really rolled up, it makes no sense," he says. "It costs you more to put them together."

Ultimately, everything is repairable, he says, but what he prefers to buy is a low-time airframe that is straight and rust-free.

"Just a tired, old bird will work for us," Johnson says. "As long as it's straight, it's better for us."

Once the airframe is straight, it gets sandblasted and powder-coated.

After that, the buildup begins. Every component is checked for wear and tear, and those that should be replaced are. While there are thousands of parts to every plane, Johnson puts the scope of this work into less than technical terms.

"We replace the bearings, and la-de-da, de-da," he says.

This may include a new set of digital flight instruments and a choice from several Avia propellers, from low noise to high "pull."

The plane may get some other performance upgrades as well. Johnson Airspray already has done several fuel tank extensions, opening up room for 88 extra gallons of fuel in the wing tanks and increasing chemical hopper capacity from 400 to 500 gallons.


The Johnson crew also designed a larger intake scoop for the big air-breathing turbine. They call it the Johnson ram air induction pressure cowl, and it looks like a big mouth under the propeller nose of a plane.

"It forces more air into your engine, is what it does," Johnson says. With his cowl, "you're really going to pound it in."

The entire front end of the plane is fiberglass, and on its side is an access panel that allows easy changing of the air filter behind the ram air cowl. It even uses a less-expensive style of air filter.

"They're about $300, and in the aviation business, that's pretty cheap," Johnson says. "Most of them -- like the factory ones -- their installation ones probably run $1,000 or better."

Kenny Halvorson in Thief River Falls, Minn., builds the cowl pieces for Johnson Airspray, whose owner appreciates his talents.

"I always say, 'You don't have to be a rocket scientist in this business, but you do have to know smart people,'" he says.

The last step is to hang a freshly overhauled Walters turbine on it, and put it up for sale.

Johnson also must have a license to recertify a once-grounded aircraft for flight.


"I have an 'I.A.,'" which is an inspector's authorization to sign off on the repairs, he says.

By the time it's cleared to fly again, the once-tired ag plane looks new, flies faster than new and has a stronger engine that's good for 2,500 flying hours. This, Johnson sells for about $400,000, half of what a new ag plane costs.

There are more than 30 of the Johnson planes, about half of which are fully refurbished, in the air these days. Despite the shaky economy, business is brisk.

"Actually the airplane sales are as good as they've ever been in the U.S.," he says. "Everybody's sold out."

Still, whenever he sees one of his freshly rejuvenated ag planes lift off to try its new feathers, he takes pride in what he and his outfit have accomplished.

"Everything's a new experience, you know? Everybody's got to take a little pride in their work," Johnson says. "That's what it's all about."

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