Accident Overview
On February 25, 2020, at approximately 1030 central standard time, an Air Tractor AT-602 (registration N5197Y) was substantially damaged during an accident near Dumas, Arkansas. The commercial pilot, who was the sole occupant, was not injured. The aircraft was being operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight.
Sequence of Events
According to the pilot, after completing a low-level aerial application operation over a field, he executed a trim pass on the north side of the field with about 495 gallons (approximately 4,133 lbs) of product in the hopper. While flying from west to east at a speed between 160 and 180 mph, the five-blade metal propeller impacted a galvanized metal bracket attached to the top of a 35-foot-tall wooden power line pole. The bracket measured about one foot wide and two feet long. The impact caused one propeller blade to separate at approximately midspan.
Following the impact, the pilot reported "extreme" vibrations throughout the engine and airframe. Oil from the engine coated the front three windshield panels. The pilot attempted to clear the oil using the windshield wiper system, but was unsuccessful.
Emergency Landing
The pilot maneuvered the aircraft to perform an emergency landing onto an east-west oriented dirt road, located about half a mile north of the wooden power line. The hopper load was not dumped before the landing. Due to reduced visibility from the oil contamination, the pilot landed while looking out the left window. During the landing sequence, both wings struck the ground, and the airplane came to rest over a ditch. The aircraft sustained substantial damage to both wings and the rudder.
Pilot Report and Contributing Factors
The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. While the wooden power line pole was previously identified by the pilot, he stated that he did not know about, nor did he see, the metal bracket attached to the top of the pole. The pilot further noted that he did not believe the glare of the sun—which was positioned 39° above the horizon at an azimuth of 143°—was a factor in the accident.
Aircraft Information
The Federal Aviation Administration (FAA)-approved Air Tractor AT-602 Airplane Flying Manual (AFM) discusses general procedures for low-level aerial application flights. However, the AFM does not contain guidance regarding post-obstacle strike actions for obstacles commonly encountered in such flights (e.g., wires, poles, towers, or trees) or emergency hopper dump procedures. Such guidance is not required by regulation.