Army Officials: Collision Between Drone and Cargo Plane Was Preventable
The mid-air collision between an Air Force cargo plane and an Army drone flying over Afghanistan earlier this week could have been prevented by a crash-avoidance system that the Army is testing, officials said.
The collision involved an Army RQ-7 Shadow UAV and an Air Force Special Operations Command MC-130.
“Had we been operating a ground-based sense-and-avoid system at the time of that incident, it would have been completely averted,” the Army’s deputy project manager for unmanned aircraft systems, Timothy Owings, told reporters during a briefing at the Association for Unmanned Vehicle Systems International conference.
The Army istesting the first phase of a ground-based radar and GPS prototype system to help remotely piloted aircraft fly safely in national airspace. Defense Department officials are eager to gain approval from the Federal Aviation Administration to fly unmanned systems in national airspace so troops can train at home bases.
The “sense-and-avoid” technology uses radar to detect incoming planes that breach the unmanned aircraft system’s airspace. When that happens, the system alerts the UAS operator who then lands the drone or moves it out of the way.
Though the investigation into Monday’s incident is still ongoing, Army officials at the conference shed some light upon what may have happened. In previous incidents encountered during training scenarios and other missions, the unmanned aircraft systems were operating according to flight plans, said Col. Robert Sova, the Army Training and Doctrine Command capabilities manager for UAS. At fault were pilots in the manned aircraft, he said, who either deviated from course or were not operating according to set procedures. “The UAS would have taken the procedure to get themselves out of harm’s way,” he said.
Officials do not want this incident to fuel perceptions that unmanned aircraft are unsafe. “It’s important to build that case base that we can, and will, operate effectively … to start operating more in national airspace,” he said.
But the mishap over Afghanistan potentially could set back prospects of military drones having unfettered access to commercial airspace. During three nights of flight testing in April of the first phase of the sense-and-avoid system, the Army flew the MQ-1C Gray Eagle at El Mirage, Calif., for just over 11 hours in the presence of FAA observers. Using the collision avoidance system, the skies were clear of conflicting air traffic 80 percent of the time, said Mary Ottman, deputy product director for UAS airspace integration concepts. On the third night, however, the aircraft experienced a software glitch that halted further testing. Detailed analysis concluded that the radar tracked every incoming aircraft properly. But a simulated radar track that was created to stimulate the oral and visual cues resulted in an error.
“The [ground-based sense and avoid] system performed properly, in that it saw an anomaly and alerted the user to the problem,” said Ottman. “The anomaly has been identified and corrected,” she added.
The Army recently conducted a test at El Mirage using a manned aircraft to verify that the system now functions properly. Officials are pursuing discussions with the FAA to resume flight tests.