NTSB Identification: CEN10CA251
14 CFR Part 137: Agricultural
Accident occurred Saturday, May 15, 2010 in Baraboo, WI
Probable Cause Approval Date: 10/21/2010
Aircraft: ROBINSON HELICOPTER R44, registration: N570MD
Injuries: 1 Uninjured.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

According to the pilot, he had just departed a gravel road (loading zone) to complete an aerial application to an alfalfa field. Shortly after departure, he executed a right turn and one of the helicopter spray booms contacted a stand of 2-1/2-foot-tall alfalfa. The helicopter then began a descending right spin. Subsequently, the spray boom dragged on the alfalfa, resulting a dynamic rollover. The main rotor blades contacted terrain and the helicopter "cartwheeled" onto its left side. Examination of the helicopter revealed damage to the main rotor blades, tail boom, tail rotor, and fuselage. The pilot recommended the following: "Ensure adequate altitude before initiating turns, and exercise more caution when over tall grass or crops."

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot's failure to maintain clearance with crops while maneuvering during aerial application.

Full narrative available

Index for May2010 | Index of months