However, such analysis was simply unreliable because drone flight patterns differed entirely from those of normal airplanes; thus, the U.S. early warning aircraft's analysis of the drone's position was essentially a futile effort.
But when the early warning aircraft tried to analyze the drone's flight trajectory, they couldn't determine its potential location. They did, however, stumble upon an unexpected boon: because the air was filled with a large amount of volcanic ash, the drone was unable to avoid it. As it flew, volcanic ash gradually covered the drone's body. Over time, more ash accumulated on the drone.
So even though the drone was completely stealthy to radar on its own, once it was coated with volcanic ash, the situation reversed. On the radar of the U.S. early warning aircraft, the volcanic ash began to reflect radar waves. By analyzing the radar echoes from the ash on the drone's body, they surprisingly managed to capture the drone's whereabouts.