A Jet for Dusting Crops
The PZL M-15 Belphegor, the only mass-produced biplane in history, is the next plane on our list. The Belphegor was invented in Poland in 1972 as a way to more efficiently crop dust farms in Soviet-run countries.
Crop dusting, however, is more of an art than most people realize, requiring maneuvers and twists to guarantee that all of the crops are covered in chemicals to aid them. Meanwhile, the Belphegor had jet power, making it extremely difficult to do what a crop duster is meant to do! The plane was considerably more expensive to buy than the planes it was supposed to replace, thus it was not only difficult to navigate but also redundant.