The Super Cub is arguably irreplaceable as are a certain number of other aircraft. Super Cub's (and Cubs) ability to do the things they do is almost unmatched, especially if you factor in the era that it was developed, many decades ago before the technology of/and availability of modern materials and manufacturing.
Like Piper, Taylor, Jamoneau, a few gentlemen designed another aircraft that is as irreplaceable as the Super Cub; the Hughes 500. The link below references the development of the Hughes 500.
More than a few veterans of Southeast Asia owe many thanks to the OH-6 (Hughes 500). Like the Cub, it is in a class by itself and continues to be an amazing unique aircraft.
vertical-rewind-unconventional-origins
Like Piper, Taylor, Jamoneau, a few gentlemen designed another aircraft that is as irreplaceable as the Super Cub; the Hughes 500. The link below references the development of the Hughes 500.
More than a few veterans of Southeast Asia owe many thanks to the OH-6 (Hughes 500). Like the Cub, it is in a class by itself and continues to be an amazing unique aircraft.
vertical-rewind-unconventional-origins