billingham. he is the director at the gao. gilligan: thank you madam chairman. since the early 1990's, we have upgraded on the airspace system. primarily supporting porter security. the list of the potential uses is expanding. the economic impact has been estimated to grow to more than $82 billion by 2025. the faa has taken steps towards integration, including the six test sites, and recently issuing the new rules. first, the status of the sites. second, how other countries are integrating it into their airspace for commercial purposes. third, critical next steps for integration. regarding the test sites in december 2014 we reported problems with the working relationships and three vacations between the faa and the test sites. for example, some of the operators reported they were not receiving guidance from faa on the kind of research needed to support integration, or how to report. officials at the faa tell us the situation has improved in part because the faa and the sites made a dedicated effort to work together through activities such as meetings and informa