A 51-year-old northwestern Minnesota man who has long chafed over aircraft flying over his property pierced a small airplane with gunfire, and the shooter explained that he was on an anti-terrorism mission, according to charges.

Chad L. Olson, of Fertile, was charged Friday in Polk County District Court with four felony counts: second-degree attempted murder, second-degree assault and two counts of first-degree criminal damage to property. Olson was arrested Friday and released on $15,000 bail before a court appearance Tuesday.

Messages were left with Olson and his attorney Tuesday seeking a response to the allegations.

According to the criminal complaint:

A pilot told a sheriff’s deputy that he flew his single-engine Cessna on Oct. 6 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 was being withheld by the Sheriff’s Office, returned to the Crookston airport without any difficulty. While cleaning his plane the next day, he spotted a bullet hole near the rear of the aircraft close to the fuselage. He estimated the damage at $20,000.

The deputy detected entrance and exit holes from what he suspected was gunfire from a high-powered rifle.

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 said.

Matthew Hegre told the Sheriff’s Office he was at Olson’s property on Oct. 6 and heard a gunshot as a plane flew by. Hegre said he then saw Olson holding a 30-06 rifle. Hegre said he saw Olson fire the rifle three times, but didn’t see him aim at the plane.

Hegre said Olson told him to not say anything. But Hegre told a sheriff’s investigator he saw Olson shoot at a plane in the spring and did so three other times during the summer. Hegre said Olson explained to him that “he was using lethal force to defend himself because the airplanes were engaged in terrorism.”