The Federal Aviation Administration is “significantly behind schedule” in its attempt to meet Congress’ September 2015 deadline for integrating commercial drones into U.S. airspace, according to an audit report. The report by the Department of Transportation’s Inspector General warns that the FAA will miss the deadline for adding drones, also known as Unmanned Aircraft Systems (UAS) to America’s National Airspace System (NAS). “FAA’s delays are due to unresolved technological, regulatory, and privacy issues, which will prevent FAA from meeting Congress’ September 30, 2015, deadline for achieving safe UAS integration,” the report said. “As a result, while it is certain that FAA will accommodate UAS operations at limited locations, it is uncertain when and if full integration of UAS into the NAS will occur.”