On May 12, 2004, a Robinson R22 BETA (registration N2301F) was involved in an aviation accident near Winsted, MN. Investigators recorded the probable cause as: The failure of the main rotor drive belts for an undetermined reason, and the pilot's misjudged flare during the autorotation. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter was damaged during a forced landing in a corn field after the pilot heard a loud bang, smelled rubber, and received a clutch warning light. Examination revealed two damaged drive belts.
Incident Overview
A helicopter sustained damage during a forced landing in a recently planted corn field. The pilot reported hearing a loud bang, smelling rubber, and receiving a clutch warning light. The pilot then autorotated the helicopter to a safe landing. The corn field had corn approximately 2 inches tall and featured rolling terrain.
Damage Description
Following the landing, the tail rotor and aft section of the tail boom were found separated from the helicopter. The landing skids were bent outward and upward.
Drive System Examination
An examination of the main drive system was conducted. The drive system consists of two independent belts, each having twin V's. These belts run in four groove pulley sheaves attached to the engine and clutch. One of the belts was split between the two V's for approximately half of the belt's circumference. The second belt was shredded. Examination of the actuator revealed no anomalies, and no other anomalies were found with respect to the drive system.