Cessna 210B accident near Opal, South Dakota, March 16, 2017

The NTSB's narrative final · quoted from the NTSB record

The pilot was making a personal cross-country flight to return the airplane to the airport where it was normally stored after the completion of an annual inspection. The route of flight passed near a grass airstrip that was adjacent to the pilot's ranch home, and the wreckage was located about 275 yards from the northwest end of the airstrip. No witnesses to the accident were identified, and it could not be determined whether the pilot was performing a low pass or had attempted a landing at the airstrip. Examination of the accident site indicated that the airplane impacted terrain in a nose-low attitude. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures. Although the reported wind at an airport about 19 miles from the accident site was from 360° at 16 knots, the wind at an airport 53 miles from the accident site was from 320° at 34 knots with gusts to 40 knots. Additionally, weather modeling identified the potential for moderate low-level wind shear (LLWS) and moderate clear air turbulence within about 100 ft of the ground, and the potential for light LLWS from 100 to 500 ft above the ground. Therefore, it is possible that the airplane encountered LLWS and turbulence that contributed to a loss of control. Further, the pilot had severe coronary artery disease, which placed him at increased risk of a cardiovascular event that may have resulted in impairment or incapacitation. The investigation was not able to determine if adverse weather conditions or an acute cardiac event contributed to the accident.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.