Piper J-3C-65-8 The Piper J-3 Cub aircraft was designed in 1937 and produced continuously until early in 1942. Beginning in 1939, nearly 75 percent of the primary trainers in the U.S. government's civilian pilot training program were J-3s. In 1942 Piper ceased producing civilian aircraft and began producing the militarized version of the J-3, identified by the Army Air Forces (AAF) as an L-4. An AAF L-4 is on display in the museum's World War II Gallery. The J-3 on display is further identified