Many "Icarus V"s were built from plans sold by Kiceniuk and it was also commercially produced by Free-Flight Systems, Inc. of Sylmar, California. The Icarus series, especially "Icarus V", were instrumental in the development of the modern 'rigid wing' hang glider. Although its performance was astounding, the foldable, portable Rogallo flexible wings retained their popularity because the Rogallo wing dramatically reduced difficulty in storage, transport, assembly and repair. In addition, the flexible wing could always be redesigned to improve the performance far more easily than a rigid wing could be designed for portability. Hang gliders eventually evolved to a slender efficient wing like that of the Icarus V while retaining the portability of the Rogallo wing.