His second project was a similar biplane design using a rotary Gnome engine. This was a step up from the Model T and had a proven track record used by early birdmen like Bleriot in his English Channel crossing (and, later, women like Harriet Quimby). The Gnome generated 50 horsepower, a great improvement, but it also had its drawbacks, like a horrible screeching sound and propensity for catching fire at awkward moments. After extensive tests, Pietenpol, not pleased with the results, called the Gnome a “growler,” and it likely never flew.​

He decided to try another tactic and bought plans for a Lincoln Sport Biplane from a popular magazine called Modern Mechanics and Inventions Flying Manual published by Fawcett and whose popular aviation writer, E. Weston “Westy” Farmer, was influential in covering the world of “homebuilt aircraft.” By now it was the late 1920s and successful designs like Edward Heath’s Parasol and O.C. Corben’s Baby Ace were being built both as finished aircraft and in kit form by their companies, and plans were being sold to those confident in their abilities as craftsmen. But these designs required some complex construction skills and equipment to manufacture welds or fabricate intricate control mechanisms that were beyond the scope of the average builder. Of course, these parts could be purchased separately by mail, a practice Pietenpol eventually offered for his own designs as well. But the Heath and Corben models also mainly recommended aircraft powerplants which were less available and much more expensive (though each manufacturer did offer plans for using motorcycle engines). Unlike Pietenpol, experimental aircraft designers thought that automobile engines were simply too underpowered. Aviation was still in its infancy in America.

Bernard Pietenpol’s big break occurred in 1930 when aviation editor “Westy” Farmer attended a fly-in in Minneapolis, Mn. In previous columns in Modern Mechanics and Inventions Flying Manual, Farmer had declared that he was not a big fan of using automotive engines in aircraft and specifically said that Ford’s Model A engine was not usable at all. Pietenpol decided to make the flight in his Air Camper up to Minneapolis to prove the editor wrong. In fact he had Finke fly a second Model A powered airship to the fly-in. Once face-to-face with Farmer, Pietenpol told the crowd, “I believe that this is the safest plane for the beginner that has ever been built.” He made such an impression on Farmer, and the rest of the crowd, that Modern Mechanics and Inventions Flying Manual published his Air Camper plans serialized in four 1931 issues. That really put Bernard Pietenpol, the Air Camper, and Cherry Grove on the aviation map. Letters arrived in bunches.

Bernard Pietenpol offered fatherly advice to his customers. For example: “If you realize that you are not capable of building a good ship, then do not try. Either buy a ship or have someone build it for you that can. Don’t build an unsafe ship.”

He also had his views about aircraft safety when it came to flying. “I do not believe in stunting, it is the cause of nearly all accidents. I believe in safe and sane flying only. My advice is, do not stunt much or take unnecessary chances.”

Unlike some of his fellow homebuilt pioneers, Bernard Pietenpol actually built very few airplanes at his Minnesota airfield/worksite, perhaps only 23. Like aircraft designer Burt Rutan decades later, Bernard Pietenpol made more of a business of providing plans for his designs. During the 1930’s, he sold thousands of sets of plans to eager builders all over the country as well as many overseas. Assembly kits were also available and he sold hundreds of them, along with his availability as a friendly personal “consultant” to any builder’s question, no matter how small. For example: “There is no point in using a lot of nails. The strength lies in the gusset plate and gluing.”