The effects of an experimental military weapon have been tied to a New Mexico plane crash that killed four people this year, according to a preliminary NTSB probe. The disaster marked the first time that GPS jamming contributed to the crash of a civilian aircraft in the U.S., according to WIRED. The accident has sparked concern about the impact of new military tech—which is increasingly being trialed to combat enemy drones—on civilian aviation. NTSB’s preliminary report detailed the events that led to the crash. Experts told the Daily Mail that GPS disruption alone shouldn’t cause a plane to crash since pilots can rely on ground-based or visual navigation.