On March 20, 1993, a Bell 47G5 (registration N7080J) operated by Soilserv, Inc. was involved in an aviation accident near Greenfield, CA. Investigators recorded the probable cause as: The pilot's failure to maintain adequate clearance from overhead powerlines while maneuvering in the spray field. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter collided with overhead powerlines while maneuvering in the northeast corner of a field being sprayed, resulting in an uncontrolled descent and ground impact.
What happened
The pilot was conducting an agricultural spraying operation when the incident occurred. At the time of the event, the aircraft was operating within the northeast corner of the designated spray field. The pilot reported navigating under a diagonal set of powerlines that crossed this specific area.
After successfully clearing the first diagonal set at the field boundary, the pilot initiated a climb to avoid a second, subsequent set of lines. During this maneuver, the aircraft failed to clear the uppermost wire of the obstacle. Following the initial contact with the wire, the helicopter lost control and descended rapidly before colliding with the ground.
The investigation
The investigation relied primarily on the pilot's account of the sequence of events. No mechanical failure was identified as a contributing factor prior to the collision. The primary finding was the insufficient clearance between the aircraft and the overhead powerlines during the avoidance maneuver.
Probable cause
The pilot's failure to maintain adequate clearance from overhead powerlines while maneuvering in the spray field.