The FAA must implement changes to the way it is funded before it can afford to embrace the myriad technologies that are envisioned for the Next Generation Air Transportation System, according to senior FAA staffers. Appearing before the Senate aviation subcommittee, Charles Leader, director of the Joint Planning and Development Office, told committee members that the controversial system of user fees and tax increases now under consideration by Congress for FAA reauthorization is a key element of FAA modernization. "Modernization and moving to NextGen is inextricably linked to changes in the FAAs financing system," Leader said. "We need to establish the financing of our current and future operations based on actual costs and investment requirements that will realize tangible benefits and increasing efficiency." General aviation groups and even the Government Accountability Office -- have dismissed the need for a wholesale change in the way the FAA is funded, saying there's plenty of money available under the current system of ticket and cargo taxes and the existing fuel tax levied on GA aircraft. As we've reported previously, the FAA claims the current airspace system is at capacity and requires a multi-billion-dollar injection of new technology to cope with increasing demand. Automatic Dependent Surveillance-Broadcast (ADS-B) is a pivotal technology identified in the FAAs plan, along with more satellite-based navigation functions like area navigation (RNAV) and required navigation performance (RNP), as ways to pack more airplanes into the system. But he also said the various systems can't be implemented in isolation. "It is important to understand that NextGen is a portfolio program," he said. "The technologies described above, and those that will be defined over the next several years, are interdependent, creating a series of transformations that will truly modernize todays system."