What happened
On July 29, 2019, an Aérospatiale AS350B, registered JA9252, crashed into a paddy field in Chikusei City, Ibaraki Prefecture, during a pesticide spraying mission. Operated by S･G･C Saga Aviation Co., Ltd., the aircraft was performing its 15th spraying pass of the day.
Earlier that morning, heavy haze had delayed the flight schedule. As the haze cleared, the pilot attempted to catch up on the workload. To avoid flying directly into the sun, the pilot adjusted the flight path to a southeast heading. While flying at approximately 12 meters above ground level, the pilot spotted power lines ahead and to the left. In an attempt to avoid a collision, the pilot applied a right aft cyclic input. During this maneuver, the aircraft's vertical stabilizer made contact with a power line, causing the rotorcraft to lose stability and crash. The impact resulted in the destruction of the aircraft and one minor injury to the captain.
The investigation
The Japan Transport Safety Board (JTSB) examined the flight history, meteorological conditions, and the configuration of the accident site. Investigators reviewed the pilot's recent flight experience and fatigue levels, noting that while the pilot's sleep schedule was irregular due to the nature of spraying operations, he had slept seven hours and did not report fatigue.
The investigation also focused on the visibility conditions and the placement of hazard signs. While the pilot had conducted a site survey prior to the mission, the hazard signs near the power lines were installed directly under the outermost lines at intervals exceeding 100 meters, rather than the 30 to 50-meter intervals recommended by safety guidelines. Furthermore, investigators analyzed the sun's position, which was approximately 42 degrees high, creating significant backlighting that likely obscured the power lines.