The Government Accountability Office (GAO), Congress’s watchdog, said on Monday that the Federal Aviation Administration (FAA) has not completed risk assessments or updated security documentation to address spoofing and jamming of radio and GPS signals, and lacks real-time detection for all spectrum-related threats, according to Reuters and The Guardian.

Hackers could transmit fraudulent clearance cancellations and cause delays and safety risks, the report said. Senator Ron Wyden called the technology used by air traffic controllers ‘incredibly insecure’; the FAA said it agreed with the report’s nine recommendations.