Cessna 140 N9474A accident near Sonora, California

Probable cause

The pilot’s failure to maintain clearance from trees during approach for landing.

NTSB analysis

The pilot performed an uneventful cross-country flight to take the passenger to a business meeting. He intended to complete the trip during the day (and return to the home airport by 1700), so he would not have to fly at night. Radar data indicated the airplane stopped at four airports before departing for the final leg to the home airport. The final stop included fueling the airplane with approximately 20 gallons of 100 low-lead aviation fuel and departing at 1702.

The airplane flew on a northbound heading for about an hour, varying its altitude between 2,000 and 3,000 ft mean sea level (msl) as it continued toward the home airport. When the airplane was about 1.5 nautical miles (nm) from the runway, it turned slightly to the right, consistent with a straight-in approach. It descended gradually until track data were lost about .75 nm from the approach end of the runway. The airplane impacted a tree with its left wing and then continued about 300 ft before coming to rest inverted between two trees.

The accident occurred 39 minutes after sunset and 11 minutes after dusk.

A witness near the accident site reported that he was working on his ranch when the daylight started to fade. He estimated it was around dusk when he heard a loud bang. He looked toward the noise and saw the airplane for about 3 seconds before he heard another bang, followed by silence. Prior to that, he heard the airplane's engine and noted it was not making any unusual sounds.

A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

The fact that the pilot did not want to fly at night indicated some apprehension on his part, and his night flying experience could not be determined. It is possible the pilot was distracted by the night conditions and unaware of what the approach to the airport looked like at night. He likely did not see the tree along the flightpath before the airplane’s impact.

Text from the NTSB. Open the NTSB docket for WPR20FA086 for the full record.