NTSB Preliminary Report Notes GPS Jamming in King Air Crash

The NTSB has released a preliminary report on the May 14 crash of a Beechcraft King Air C90, registered as N249CP, that killed all four occupants during an air ambulance flight in New Mexico. Operated by Generation Jets under Part 135, the airplane departed Roswell Air Center (KROW), bound for Sierra Blanca Regional Airport (KSRR) in Ruidoso to pick up a patient for transport to Albuquerque, the NTSB said. The two pilots worked for Generation Jets; the two passengers were flight nurses with Trans Aero MedEvac.

Before takeoff, the crew’s briefing noted that the military had scheduled GPS jamming across the area and altitudes the flight would cross, the report said. About eight minutes after departure, the crew informed controllers at Albuquerque Center that they had lost GPS capability and needed a heading. Controllers asked the military to stop the jamming. Three other aircraft also reported losing GPS around the same time, the agency noted.

Recorded ADS-B data from the King Air thinned to roughly one-minute intervals during the jamming, returned to intervals of two to three seconds after that request, and thinned again after controllers told the military it could resume jamming, the report said. Investigators also noted that the airplane’s onboard Spidertracks unit recorded a GPS altitude about 600 feet higher than its ADS-B altitude, and that the ADS-B record contained large gaps.

The crew reported Ruidoso in sight and accepted a visual approach in clear conditions on a dark, moonless night. Descending toward the airport, the King Air struck terrain in the Capitan Mountains at an elevation of about 9,950 feet msl, 730 feet east of and 230 feet below the range’s summit radio facility. A post-crash fire spread into a nearby forest.

At the destination, the airport’s automated weather observation system, which provides the local altimeter setting, was out of service, with no current observation or forecast available, the report said. Both of its published instrument approaches to Runway 24—ILS and the RNAV—are unauthorized without that setting, so with the system down, neither could be flown.

As a preliminary report, the document presents factual findings without analyzing them, identifying a probable cause, or connecting any factor to the accident. The NTSB typically issues a final report, including a probable cause, within two years after an accident.