TB 30 EPSILON N759F accident near Apache Junction, Arizona

Probable cause

The pilot’s controlled flight into the mountainous terrain due to diminished depth perception as a result of the shadowing effect from the sun’s position. Contributing to the accident was the decision by all three pilots to fly low altitude around the mountainous terrain.

NTSB analysis

The formation of three airplanes departed about 2 hrs and 20 minutes after sunrise to fly to an airport for lunch. The accident airplane was loaded with the pilot and a passenger, a full load of fuel, and an undetermined amount of baggage when they took off. The accident pilot, flying in the No. 2 position, intended to continue flying a solo cross-country after lunch. The flight planned to fly at low altitude around a local mountainous area en route to the lunch location. The No. 3 pilot reported that, during departure and before flying around the mountains, the accident airplane was having difficulty keeping up with the other two airplanes.

Several witnesses observed the airplanes flying to the south along the west side of the mountains at a low altitude. They reported that the lead and No. 2 airplanes were close together, flying similar profiles, while the No. 3 airplane was further behind.

Both pilots reported they struggled with depth perception when flying around the mountains. The No. 3 pilot reported that just before the accident, he observed the No. 2 airplane pass under his airplane from right to left toward the terrain. The nose of the airplane pitched up and down several times, but the trajectory of the airplane did not appear to change. He said the pilot of the No. 2 airplane did not make any radio calls or report any problems before the accident.

A home security camera, facing east, captured the moment the No. 2 airplane impacted terrain. No airplanes were identifiable in the video. The video showed the west facing slopes of the mountains were shadowed and terrain features were not defined.

It is possible the airplane was not performing as well as the other two airplanes due to its loading, but the evidence was insufficient to say whether that could have been a factor in the pilot’s ability to avoid the terrain. The evidence is consistent with the shadowing effects resulting from the positioning of the sun creating depth perception difficulties for the pilot. The pilot likely failed to recognize the significance of rising terrain in front of the airplane until there was insufficient time to avoid it, resulting in controlled flight into terrain. Contributing to the accident was the decision by all three pilots to fly at a low altitude around the mountainous terrain.

Text from the NTSB. Open the NTSB docket for WPR23FA223 for the full record.