Piper PA-24-250 N7471P accident near Black Canyon City, Arizona

Probable cause

The pilot's decision to continue VFR flight into instrument meteorological weather conditions which resulted in controlled flight into terrain. Contributing to the accident were low ceilings, reduced visibility, and mountainous terrain.

NTSB analysis

The pilot departed under visual flight rules (VFR) for a planned cross-country flight. Recorded radar data revealed that about 50 miles east of the accident site, the flight was at a pressure altitude of 8,500 feet mean sea level (msl) with a flight path on west-southwest heading. The radar data depicted a descent from 6,900 feet to 5,700 feet msl at the last recorded radar target. The last radar target was located about 0.32 miles southeast of the accident site, at 5,700 feet msl. Review of recorded radio communications between the pilot and the Air Route Traffic Control Center (ARTCC) revealed that at about 25 minutes prior to the accident, the pilot informed the controller that he was “going to be drifting down just a little bit lower to stay under the clouds." The wreckage was located within mountainous terrain at an elevation of 5,488 feet msl. Wreckage and impact signatures at the accident site were consistent with a level attitude at the time of collision with terrain. Examination of the airframe and engine revealed no anomalies that would have precluded normal operation. Review of recorded weather data from weather reporting stations surrounding the accident site revealed multiple layers of low clouds over the accident site during the time frame of the accident. Visible and infrared satellite imagery surrounding the time period of the accident depicted a broken to overcast layer of stratocumulus to nimbostratus clouds over the accident site. A weather reporting station located approximately 3 miles west of the accident site at an elevation of 5,250 feet reported wind from 216 degrees at 22 knots, gusting to 35 knots during the time period of the accident. Coupled with saturated conditions and 100 percent relative humidity and no temperature dew point spread, this is consistent with the station being in the clouds with instrument meteorological conditions (IMC) existing. A review of the radar and satellite imagery confirms low overcast conditions over the station and accident site. A second weather reporting station located approximately 8 miles northeast of the accident site at an elevation of 2,960 feet msl, also reported high relative humidity at 80 percent, which supported low level clouds and potential mountain obscuration in the area.

Text from the NTSB. Open the NTSB docket for WPR10FA005 for the full record.