A medical transport plane crash that killed four people in New Mexico this spring has been linked to a U.S. military GPS jamming exercise, a preliminary report released by the National Transportation Safety Board shows.

The medevac plane, operated by Generation Jets, crashed about 12:15 a.m. MT on May 14 near Lincoln in the southeastern part of the state, the NTSB wrote in its report released Aug. 5.

The town is along U.S. Route 380 about 60 miles west of Roswell.

The aircraft, a Beechcraft King Air 90, was traveling from Roswell to Sierra Blanca Regional Airport near Ruidoso, New Mexico, when it crashed, NTSB investigators said. The plane and air crew were both based at Roswell Air Center (ROW), the report said, and the two passengers on board were flight nurses employed by Trans Aero Medical Services.

The plane lost communications and radar, and did not arrive as scheduled, Lincoln County officials said in a news release at the time.

According to the NTSB preliminary report, the aircraft left ROW at 11:52 p.m. MT on May 13 to pick up a patient for transport to Albuquerque.

“GPS jamming activities that encompassed the area around the accident flight were being conducted by the United States military during the time of the flight,” investigators wrote.

Airplane’s radio transmission ‘stepped on by other radio traffic’

Prior to the crash, the report reads, a pilot reported they had “a visual on Ruidoso,” but their radio transmission “was stepped on by other radio traffic.”

The plane, investigators said, then experienced a loss of GPS navigation capability.

According to investigators, other planes in the area also experienced similar GPS issues the same day of the crash.

Who died in New Mexico medical transport airplane crash?

Trans Aero Medevac previously identified the victims as pilots Keelan Clark and Ali Kawsara, and flight nurses Jamie Novick and Sarah Clark.

“Together with their families, friends, colleagues, first responders, healthcare partners, and community members, we will celebrate their lives, recognize their service, and remember the lasting impact they made on so many,” the emergency service transportation company that serves southeastern New Mexico and Western Texas wrote.

The crash caused a weeks-long wildfire in the Capitan Mountains that the U.S. Forest Service reported spread to nearly 5 acres.

As of Aug. 8, NTSB investigators had not yet determined the probable cause of the crash or any contributing factors to the accident. A final report is expected to be released in the coming months.

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at nalund@usatoday.com and follow her on X @nataliealund.