My 1954 Cessna 180 was mostly stock when I bought it. That didnt last long. I quickly added a STOL kit, wing extensions and bigger tires. As a result, the stall speed went down, useful load went up and, to a degree, the pilots operating handbook, POH, became a work of fiction because it no longer matches the actual airplane. This outcome is not uncommon.
Much of todays GA fleet consists of stock airplanes that have undergone substantial modifications over the years. Prospective buyers can peruse numerous planes of the same model year all they want, but they rarely will find two with the same airframe. Changes can include-but are not limited to-additional fuel capacity, turbocharging, STOL kits, vortex generators and many, many more. These modifications all have one thing in common: They will fundamentally change the airplanes performance.
