Eurocopter AS-350BA C-GGLM

Summary

On 29 May 2006 at about 19:00 local time, a Eurocopter AS-350BA registered C-GGLM was involved in an accident near Goshen, New York, United States. 2 people were on board and 2 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 May 2006 at 19:00

Classification

Accident

Location

Goshen, New York, United States

Coordinates

41.3742, -74.3431

Aircraft

Eurocopter AS-350BA

Registration

C-GGLM

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Camden → Glen Falls

Aircraft damage

Substantial

Weather

VMC

NTSB number

NYC06LA121

2 people had minor injuries.

Improper maintenance of the hydraulic pump/coupling, which resulted in a failure of the hydraulic flight control system. Factors included the substandard materials of the hydraulic pump drive shaft and coupling, and the pilot's failure to maintain an adequate airspeed during the landing.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

About 45 minutes into a cross-country flight, the helicopter experienced a hydraulic system failure. The pilot subsequently elected to perform a precautionary landing in a field. During the landing attempt, the pilot slowed the helicopter and it began to yaw left. The pilot attempted to correct the yaw, but was unable to overcome the "stiffness" of the right anti-torque pedal. The helicopter continued to yaw left, landed "hard," and rolled over. Examination of the helicopter's hydraulic system revealed that the hydraulic pump drive shaft splines and the attaching drive coupling splines were severely worn, to the point that they could no longer drive the hydraulic pump. Metallurgical hardness testing of both the drive shaft and the coupling revealed that the surfaces of the splines were below the manufacturer's specified hardness. Examination of the grease found trapped between the remaining portions of the hydraulic shaft pump splines revealed that it was hard packed and gray colored, suggesting that it had been in place for a significant period of time. The minimal amount of grease observed in the coupling sleeve did not satisfy the "generously filled" description referred to in the manufacturer's service bulletin, and required by a subsequent airworthiness directive. Examination of the helicopter's maintenance records revealed that since the issuance of the airworthiness directive, the helicopter had not been in compliance with either the calendar or flight time requirements. The helicopter's flight manual cautioned pilots operating the helicopter without hydraulic assistance, "Do not attempt to carry out hover flight or any low speed maneuver. The intensity and direction of the control feedback forces will change rapidly. This will result in excessive pilot workload, poor aircraft control, and possible loss of control."

Quoted verbatim from the NTSB record.