Many people called the Stearman Model 75 the “Pilot Maker,” and for good reason. The biplane introduced more of World War II’s “Greatest Generation” to flight than any other airplane.

The popular name for the U.S. Navy’s version of the Model 75 was the “Yellow Peril.”

The Army Air Corps’ Stearman planes were called “The Kaydet.”

A surprising number of the Stearman company’s most-produced plane are still flying today, and many of the survivors — they’re between 63 and 73 years old – will make their way to Galesburg Municipal Airport in September for the annual National Stearman Fly-In.

The event is the largest annual gathering of its type in the world. The colors and the sounds of these vintage warbirds are a treat for the senses.

Here’s a bit of history about how it all came to be:

As war clouds gathered in the last half of the 1930s, both Army and Navy officials realized they would need a new trainer to produce the pilots needed for the coming conflict. Both branches conducted their own trials for a trainer, and amazingly both selected the Stearman Model 75. Its rugged construction and its handling qualities were well-suited to teaching soldiers and sailors to fly.

Times were turbulent in the aircraft industry, too. On Aug. 15, 1929, designer- manufacturer Lloyd Stearman’s company became part of United Aircraft & Transport Corp., which consisted of United Airlines, Pratt & Whitney Engines, Standard Props, Boeing, Hamilton Aircraft, Sikorsky Aircraft and Vought Aircraft.

The Model 75 traces its roots to Stearman’s Model 6 “Cloudboy” (YPT-9), which he designed in 1930. Ten were built starting in 1931.

In December 1930, Stearman – unhappy with the conglomerate — resigned from his namesake company. He remained on the board of directors for a short time, but soon moved back to California and became the president of Lockheed Aircraft Co.

In 1933, Stearman Co.’s chief engineer, Mac Short, and engineers Jack Clark and Harold Zipp used a rough sketch of the “Cloudboy” as the basis for the Stearman Model 70. Refinements to the Model 70 became the Model 73 (NS-1), which was sold to the U.S. Navy – the first Stearman design sold to the military in quantity.

On Sept. 26, 1934, government trust-busters broke United Aircraft into separate airline and manufacturing entities.

More refinements to the Model 73 produced the Model 75.

The Stearman company became a subsidiary of Boeing Aircraft Co. on April 1, 1938. The division’s Wichita, KS, factory built 8,428 of the Model 75 biplanes, plus enough spare parts to assemble another 2,000, from 1935 until February 1945. The last Stearman came off the assembly line hardly noticed, eclipsed by a celebration in another factory across town where Boeing employees completed the 1,000th B-29 bomber.

It’s not clear exactly how many Stearmans are around today, aviation historians say. The federal registry lists about 2,000, but many of those are little more than a few unassembled parts. Some exist just as a piece of paper. Knowledgeable enthusiasts estimate about 1,000 Stearmans around the world are still flying.

After World War II, Stearmans were sold as surplus. A single plane could be bought for $500. Many were converted for use as crop dusters and were working airplanes until newer, more powerful craft began  replacing them.

Many of the survivors have been restored to their original colors — blue fuselage and yellow wings for “The Kaydet,” and mostly all-yellow for Navy planes. Others wear custom paint schemes and sport larger engines, cowls and wheel pants selected by their owners.

The price of Stearmans today ranges from $70,000 up, depending on condition, quality of restoration, time accumulated on the airframe and engine, and other factors.

In addition to the military planes, a handful of earlier Lloyd Stearman’s civilian designs dating from the late 1920s often can be found at the Fly-In.