Amateur-built VANS RV-8A N131RP accident near Lucas, Kansas

Probable cause

The noninstrument-rated pilot's inadvertent entry into instrument meteorological conditions, which resulted in his spatial disorientation and a subsequent loss of airplane control.

NTSB analysis

The noninstrument-rated pilot was flying the accident airplane in a trail formation behind another airplane as the airplanes maneuvered between cloud layers about 7,500 feet mean sea level. The lead airplane pilot estimated that the cloud layers were at least 4,000 feet above and 1,000 feet below the airplanes and that visibility was about 4 to 5 miles. While en route, the accident pilot lost sight of the lead airplane and asked the lead pilot to relay his heading. The lead pilot reported his heading and indicated that he saw the accident airplane about 1 mile behind and 800 feet below the lead airplane (about 200 feet above the lower cloud layer). Shortly after, the accident pilot again asked for the lead airplane's heading, and the lead pilot reported his altitude but could not visually acquire the accident airplane. No further radio transmissions were received from the accident pilot. A witness reported hearing the airplanes circling overhead, the sound of impact, and then one airplane flying overhead. He added that the weather was rain and low clouds. Ground scar and airplane damage were consistent with the accident airplane impacting terrain in a 60-degree left turn at high speed.

The accident pilot's last aviation medical examination occurred about 11 1/2 years before the accident. On the medical application, the pilot reported that he was being treated for coronary artery disease. This medical certificate was not valid for any class 2 years later, and no record was found indicating whether the pilot had obtained another medical certificate. The condition of the pilot's body did not allow for a thorough autopsy, and medical impairment could not be determined. Due to the airplane's last known proximity to a cloud layer, it is likely that the pilot was attempting to visually acquire the other airplane while he descended into a cloud layer. The pilot's inadvertent and unexpected entry into instrument meteorological conditions likely resulted in his spatial disorientation and subsequent loss of airplane control.

Text from the NTSB. Open the NTSB docket for CEN13LA439 for the full record.