Casualties unknown

2003-06-13: Bell 47-G4 (N9017N) — Porterville, CA

Porterville, CA, US

On June 13, 2003, a Bell 47-G4 (registration N9017N) was involved in an aviation accident near Porterville, CA. Investigators recorded the probable cause as: loss of control for undetermined reasons. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

While en route to a field for aerial pesticide application, a helicopter suddenly pitched nose down and impacted the ground. Post-accident examination found no preimpact anomalies.

Introduction

A helicopter engaged in aerial pesticide application experienced a sudden nose-down pitch and impacted the ground during a flight to a destination field. The accident occurred while the pilot was navigating near an intersection of two roads.

Sequence of Events

The pilot departed from a service truck in a southwest direction, heading toward a field located 2 miles southwest of the truck. While crossing an east/west road, the pilot executed a wide left turn, proceeding northbound. At the intersection of the east/west road and a north/south road, the helicopter maneuvered upward and over power lines that were parallel to the east/west road. Subsequently, the helicopter turned left approximately 90 degrees to the west, followed by another left turn of 90 degrees to the south. During this maneuver, the nose suddenly pitched down, and the helicopter impacted the ground. The wreckage site was located half a block north of the intersection.

Wreckage and Examination

A post-accident examination of the airframe and engine revealed no preimpact anomalies. No specific mechanical or structural failures were identified that could explain the sudden pitch-down event.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20030618X00893. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.