Eurocopter France EC135T1 N135NW

Summary

On 3 January 2005 at about 20:46 local time, a Eurocopter France EC135T1 registered N135NW was involved in an accident near Casa Grande, Arizona, United States. 2 people were on board and one 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

3 January 2005 at 20:46

Classification

Accident

Location

Casa Grande, Arizona, United States

Coordinates

32.9547, -111.7669

Aircraft

Eurocopter France EC135T1

Registration

N135NW

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Instructional

Phase of flight

Not recorded

Route

Mesa → Casa Grande

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX05LA060

1 person had minor injuries.

the separation of a main rotor control link due to improper maintenance installation.

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

Read the full NTSB narrative

Following the in-flight separation of a main rotor control link, the pilots lost control and the helicopter hit the ground hard and rolled over. The pilots reported that as they turned base in the traffic pattern for landing at the airport, the helicopter pitched up violently and rolled to the right, followed by a hard roll to the left. Both pilots got on the controls and tried to regain control of the helicopter. The pilots lowered the collective and started down for a landing. During the descent, the pitching and rolling continued intermittently with the roll attitude reaching beyond 60 degrees. As the helicopter neared the ground, the pilots flared and the helicopter hit the ground in a tail low attitude and rolled over. A post accident examination of the helicopter, and examination of maintenance records by a Federal Aviation Administration inspector, occurred on site and after recovery. During the course of the examination it was determined that maintenance personnel had removed cyclic control links from the cyclic control levers to check the ball joints for excess free play during an inspection. The links are attached to the cyclic levers with bolts and castle nuts with cotter pins through the castle nuts as a safety locking device. The right lateral cyclic control link was found broken. The nut on the upper bolt was 1/4-inch away from the side of the attachment point. There was no evidence of the cotter pins having been added to the castle nuts after the link inspection/reinstallation.

Quoted verbatim from the NTSB record.