Military GPS jamming disrupted a medevac flight before fatal New Mexico crash

Why it matters

Military GPS testing can affect civilian aircraft hundreds of miles away. This crash puts pressure on the FAA and armed services to reconsider how those exercises are scheduled, communicated and halted when crews report navigation failures.

A U.S. military GPS-jamming exercise disrupted the navigation system of an air ambulance before it struck a New Mexico mountainside on May 14th, killing all four people aboard, according to a National Transportation Safety Board preliminary report.

The sequence documented by investigators puts military electronic-warfare testing directly into the chain of events preceding a fatal civilian aviation accident. It does not establish that jamming caused the crash. The NTSB has yet to issue a probable-cause finding, and its preliminary report says its information remains subject to change.

WIRED reported on July 30th that the flight was operating while military units gathered for NAVFEST, an annual exercise at White Sands Missile Range involving technology for disrupting GPS and operating through similar interference. The case shows how testing equipment built for drone and electronic warfare can reach civilian aircraft far outside the immediate test site.

The Beechcraft C90 left Roswell Air Center at about 11:52 p.m. on May 13th for Sierra Blanca Regional Airport near Ruidoso. Generation Jets operated the aircraft and employed pilots Keelan Clark and Ali Kawsara. Trans Aero MedEvac employed flight nurses Jamie Novick and Sarah Clark. The crew was heading to Ruidoso to pick up a patient for transport to Albuquerque.

The night was clear and almost completely dark, with 0% moon illumination, according to investigators. The Capitan Mountains, which rise above 10,000 feet between the aircraft's eventual position and the airport, would have been difficult to distinguish from the night sky.

GPS fails during the flight

Minutes after departure, the crew requested an instrument-flight clearance and was assigned an altitude of 12,000 feet. At 12:00 a.m., an Albuquerque air traffic controller told the pilots that the aircraft was flying at 13,000 feet. The crew said it was correcting the altitude, had lost GPS capability and needed a heading.

The controller initially directed the pilots toward Ruidoso. The crew requested a GPS-based RNAV approach before switching to an instrument landing system approach because GPS navigation was unavailable. At 12:01 a.m., the controller asked an operations supervisor to have the military stop jamming.

The disruption extended beyond the medevac flight. Three other aircraft in the area reported losing GPS, and one needed additional help identifying a ground-based navigation aid. The medevac aircraft continued north for about 20 nautical miles while the controller handled other traffic and prepared to guide it toward the instrument approach.

The military stopped the jamming around 12:05 a.m., the NTSB said. About three minutes later, the crew reported seeing Ruidoso and asked to make a visual approach. The controller approved that request. The pilots then turned southwest toward the airport, placing the Capitan Mountains across their route.

At about 12:10 a.m., the air traffic control supervisor told the military that the aircraft was making a visual approach and that GPS jamming could resume. Tracking data again became less frequent around the same time, dropping from intervals of two to three seconds to about one minute.

The aircraft descended toward Ruidoso. Its final tracking point showed it at a GPS-derived altitude of 9,823 feet, traveling at 150 knots. It hit terrain at an elevation of about 9,950 feet, approximately 230 feet below a radio facility near the mountain summit. The impact and fire destroyed the aircraft and started a wildfire.

A warning covered hundreds of miles

The FAA had issued an advisory for GPS-interference testing at White Sands from May 12th through May 18th. The notice included the period of the accident flight.

The detailed notice warned that GPS, satellite-based augmentation systems and GPS-dependent surveillance could be unavailable within a 240-nautical-mile radius at altitudes from 4,000 feet above ground level through 10,000 feet. At higher altitudes, the affected radius reached as far as 366 nautical miles.

The crew's ForeFlight briefing contained the GPS warning, the NTSB found. It also showed that Sierra Blanca Regional Airport's automated weather observation system was out of service. Both available instrument approaches required a local altimeter setting and were listed as unavailable without one.

Those details leave investigators with several overlapping issues to resolve: the loss of GPS, the crew's transition between navigation methods, the decision to accept a visual approach on a moonless night, terrain awareness, the unavailable airport weather system and air traffic control's decision to allow jamming to resume.

Aviation experts cautioned against treating the GPS outage alone as a sufficient explanation. Retired airline pilot John Cox told the Associated Press that an aircraft should remain operable after losing GPS. Steve Arroyo, a former United Airlines pilot, said crews should be prepared to use ground-based navigation or fly visually, while noting that GPS provides valuable precision in terrain where navigation errors leave little margin.

The military interference nevertheless removed a navigation layer during a short-notice medical flight over mountainous terrain. It also increased the controller's workload by affecting several aircraft at once. The NTSB's final report will determine how much weight those conditions carried compared with the crew's decisions and other operational factors.