During the last two decades new types of air transportation vehicles have been developed. Integration of new aircraft types in controlled airspace requires implimintation of new surveillance technologies on board to ensure the safety of air transportation. On-board transmitter of Automatic Dependent Surveillance-Broadcast (ADS-B) will be required for any airspace user soon. ADS-B is considered the main safety system in the next generation of civil aviation. Performance of new flight vehicles requires minimizing size, reducing power, increasing functional level, and minimizing total costs. In the paper, we study potential of cheap software-defined radio like HackRF One to support low-cost on-board ADS-B equipment for civil aviation. We create a library of classes in C++ for automatic ADS-B message generation based on input data. Also, developed library was integrated into a separate software block in GNU Radio Companion. Developed block could be easily used in a variety of applications including on-board transmitter to support ADS-B.