Presenters at an RTCA symposium in Washington, D.C., last week warned that the FAA’s ambitious NextGen overhaul of the ATC system in the U.S. faces daunting challenges that must be addressed now to avoid delays and cost overruns in the future. But FAA officials speaking at the event also pointed to progress in deploying ADS-B (automatic dependent surveillance-broadcast) ground stations across the U.S. and redesigning airspace around the nation’s busiest airports as reasons to be confident that NextGen initiatives under way now will pay significant dividends by the end of this decade. “We’ve made good progress and we should all be proud of that,” said FAA director of surveillance and broadcast services Vinny Capezzuto, “but there’s still much work to be done.” A special aviation rulemaking committee formed in July has been tasked with exploring applications for use with ADS-B IN avionics, which can deliver operational information and other data to properly equipped aircraft. Panelists also debated how to integrate unmanned aerial vehicles in U.S. civil airspace and discussed the progress in speeding the deployment of controller-pilot datalink communications, which are predicted to be in wide use at most large hub airports and ATC centers by 2018.