Primary finding
Probable cause
the commercial pilot's failure to maintain clearance from terrain. Related factors are sun glare and rising terrain.
Investigator assessment
Analysis narrative
The pilot stated he was involved in aerial application of herbicide. He reported he was making a spray run on a westerly heading with the sun in his eyes and the airplane impacted rising terrain. The pilot stated the terrain rose sharply and he did not notice the increase in terrain elevation.
Source record
Factual narrative
On March 14, 1994, at 1830 central standard time, a Grumman G164A, N9686, operated by Max Birney Aerial Spraying, Inc. impacted rising terrain during an aerial application swath run in the vicinity of Sublette, Kansas. The pilot, the sole occupant, reported no injuries. Visual meteorological conditions prevailed for the local flight, no flight plan was filed. The flight operated under 14 CFR Part 137, and originated from a private airstrip in Sublette, Kansas approximately 1815. The pilot reported he was flying on a westerly heading during an herbicide application spray run. He stated the sun was in his eyes "...setting on the horizon..." and he did not observe an increase in terrain elevation. The pilot reported the landing gear struck the terrain and the airplane "...flipped...end over end...coming to stop right side up." The pilot's safety recommendation was to fly higher during spray runs. -