On October 5, 1997, a Hiller UH-12C (registration N49983) was involved in an aviation accident near Bennington, VT. Investigators recorded the probable cause as: The failure of the cyclic control due to an improper modification by the pilot/owner. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter rolled right and struck the ground after the cyclic stick detached from the pilot's controls during a hover demonstration. The stick had been modified by attaching a military-style cyclic via a repaired joint, but maintenance records did not indicate who performed the modification.
Incident Overview
A certificated flight instructor (CFI), who also owned the helicopter, was demonstrating hovering techniques to a student pilot. During the demonstration, the student pilot attempted to hover the helicopter, at which point the helicopter began to roll to the right. The CFI reached for his controls, but the top of the cyclic stick detached. Consequently, the helicopter continued to roll right and collided with the ground.
Examination Findings
Post-accident examination revealed that the cyclic stick had been replaced with a military-style cyclic. The owner reported that the stick had been cut down by removing a section, and the cyclic separated at the repaired joint. A review of maintenance records did not disclose who performed the modification or when it occurred.
What happened in the 5 Oct 1997 Hiller UH-12C accident near Bennington, VT?
A helicopter rolled right and struck the ground after the cyclic stick detached from the pilot's controls during a hover demonstration. The stick had been modified by attaching a military-style cyclic via a repaired joint, but maintenance records did not indicate who performed the modification.
What aircraft was involved and where did it happen?
The accident on 5 Oct 1997 involved a Hiller UH-12C, registration N49983, at Bennington, VT.
What was the probable cause of the accident?
The failure of the cyclic control due to an improper modification by the pilot/owner.
A SkyWalk Join't 3 paraglider crashed into the ground near Las Vizcachas, Chile, on September 1, 2024. The pilot and passenger sustained serious spinal…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2024-09-01DGAC Chile
A Cessna 172N struck electrical cables while on final approach to land at Aucó Aerodrome in Chile. The pilot was uninjured, but the aircraft sustained damage…
A Bombardier DHC-8-402 suffered a tail strike during landing at Puerto Williams on September 9, 2024. All 76 occupants were unharmed, but the aircraft…
A MYD JS-MD 3 glider veered off the runway and struck a wall at Vitacura Aerodrome on January 6, 2025. The pilot was uninjured, but the aircraft sustained…
A recreational paraglider flight in Puchuncaví, Chile, ended with the pilot sustaining serious injuries after a rapid descent and impact with a hillside on…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2025-03-29DGAC Chile
A Tecnam P2006T landed on its belly at an aerodrome in Poland after the crew failed to confirm landing gear deployment. The incident resulted in no injuries…