A judge has ruled that a man whose gunfire struck a small airplane flying over northwestern Minnesota is severely “delusional” and unable to stand trial.

Chad L. Olson, who turns 52 on Thursday, has been ordered by Polk County District Judge Jeffrey Remick to be housed and receive treatment at the state-licensed Northwest Regional Corrections Center in Crookston.

In the meantime, the judge has put on hold the prosecution of Olson on charges of second-degree attempted murder, second-degree assault and two counts of first-degree criminal damage to property. Remick on Tuesday scheduled a May court date for further review of the case.

Olson, of Fertile, who has long chafed at aircraft flying over his property, pierced the airplane with gunfire on Oct. 6 and explained that he was on an anti-terrorism mission, according to the criminal complaint.

Remick’s ruling that Olson was mentally incompetent to assist in his own defense came after the defendant was examined by a doctor Oct. 31.

Dr. Charles Chmielewski concluded that Olson has a case of “delusional disorder … with multiple episodes, quite severe,” the judge’s ruling read.

Pointing to a concern that Olson might hurt himself or others, the doctor recommended that the defendant be moved to the corrections center, a secure treatment facility.

At the time Olson was arrested, he objected to his placement, the judge’s ruling noted.

A pilot told a sheriff’s deputy that he flew his single-engine Cessna from the Crookston airport to nearby Fertile and was on his third or fourth “touch-and-go” landing and takeoff when he heard a “twang” while flying over a greenhouse.

The pilot, whose identity has remained undisclosed by authorities, returned to the Crookston airport without difficulty. He estimated the damage to his plane from the rifle gunfire at $20,000.

Olson, who lives under the flight path of the plane, was known by authorities for making several complaints about low-flying aircraft. In mid-May, one of Olson’s neighbors reported hearing gunfire after an airplane flew by.

A Federal Aviation Administration (FAA) worker told the Sheriff’s Office that Olson had been harassing the agency with complaints about planes flying over his property. Olson told the FAA he “may have to use lethal force if he felt threatened by the airplanes,” the charges against him read.

Another man, Matthew Hegre, told the Sheriff’s Office that Olson explained to him that “he was using lethal force to defend himself because the airplanes were engaged in terrorism.”