A U.S. military GPS-jamming exercise was taking place when a medical transport plane lost satellite navigation before a fatal crash in New Mexico, according to information cited from the NTSB’s preliminary investigation. The Beechcraft King Air encountered navigation problems while approaching Sierra Blanca Regional Airport and later struck mountainous terrain, killing everyone aboard. The preliminary evidence indicates GPS interference contributed to a chain of events, but investigators have not issued a final probable cause. The NTSB’s final report is still pending.