Aviation Accident Summaries

Aviation Accident Summary WPR19LA168

Brewster, WA, USA

Aircraft #1

N955TC

Sikorsky UH19

Analysis

The pilot-in-command (PIC) was evaluating another pilot as a new job applicant. While the applicant-pilot was manipulating the helicopter controls, the PIC heard a “bang” and noted an overspeed indication on the tachometer. He subsequently took control of the helicopter and performed an autorotation that resulted in a hard landing, which substantially damaged the helicopter. The Federal Aviation Administration and operator surmised that the main drive line system clutch and torque converter failed, which resulted in the engine overspeed. However, the operator did not respond to investigators or submit a NTSB Form 6120.1, Pilot/Operator Aircraft Accident Incident Report, nor was a follow-up examination of the helicopter able to be scheduled and performed by the NTSB investigator. Due to the operator’s lack of cooperation during the investigation, the NTSB investigator was unable to definitively determine the cause of the accident.

Factual Information

On May 28, 2019, about 1710 Pacific daylight time, a Sikorsky UH-19D helicopter, N955TC, was substantially damaged when it was involved in an accident near Brewster, Washington. One pilot received minor injuries, while the second pilot was uninjured. The helicopter was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as an evaluation flight. The day after the accident, Federal Aviation Administration (FAA) inspectors interviewed the pilot-in-command (PIC) who informed the inspectors that the purpose of the flight was to evaluate the other pilot as a “new job applicant” for cherry drying flights. The applicant-pilot was flying the helicopter when the PIC heard a “bang”, observed the over-speed on the tachometer and saw the “applicant-pilot” frozen on the controls. The PIC took over the controls and executed an autorotation from about 20-50 ft agl. The helicopter subsequently landed hard, separating the tailboom from the fuselage and collapsing the landing gear, which resulted in substantial damage. The applicant-pilot was uninjured but remained in the hospital and was discharged the next day with no forwarding address or phone number. The FAA inspectors and the operator surmised that the main drive line system clutch and torque converter failed, which resulted in the engine over-speed. The NTSB investigator attempted to contact the operator to discuss future examination of the helicopter and to obtain the NTSB Pilot/Operator Aircraft Accident/Incident Report Form 6120.1. However, all attempts to contact the operator were unsuccessful, and the proposed follow-up examination of the helicopter by the NTSB was not performed.

Probable Cause and Findings

A reported mechanical malfunction and a hard landing for reasons that could not be determined based on available evidence.

 

Source: NTSB Aviation Accident Database

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