Bristow Helicopter crash: AIB identifies faulty Control Pushrod as possible cause

Faulty Control Pushrod may have accounted for the crash into Lagos lagoon of a Kikorsky S-76C+ Helicopter marked 5N-BGD on August 12, 2015 that killed six of the twelve souls onboard. The ill-fated Helicopter was operated by Bristow Helicopters, Nigeria.

According to preliminary report released in Lagos on Tuesday by Accident Investigation Bureau (AIB), the crashed   Helicopter had its’’Control Pushrod tube separated from Control rod end with the bearing and the Jamnut’’.

The report released by the Commissioner of AIB, Dr. Felix Abali further stated that ’’the Jamnut was loose and was not seating against the control rod’’.

The Helicopter manufactured in 2003, the AIB report said had ‘’no records of any deferred defects in the tech log’’.

It was reported that ‘’preliminary flight recorder data indicated that at 1000 ft and 120 kts,the helicopter sudden pitch up, and left roll with varying attitude of yaw, roll and pitch for 12 seconds until it impacted water at about 1531 hrs.’’

Meanwhile, following the outcome of the AIB preliminary investigation, Kikorsky Aircraft Corporation had since September 10, 2015 issued Alert Service Bulletin (ASB) 76-67-57 on all S-76 model Helicopters equipped with Control Pushrod Assembly P/N 76400-0034-059 and 76400-00014-071.

 Further Information and Investigative Action.

Future investigative activities will include, but not limited to, the following:

 · Metallurgical examination of the Main Servo Input Control Pushrod (MSICP).

 · Evaluation of the aircraft approved maintenance program.

 · Determination of the helicopter maintenance history.

· Follow-up examination of the engines and aircraft flight control components.

 · Detailed reconstruction of flight based on recorded data.

 · Analysis of the helicopter performance.

 · Interview of relevant personnel.

· The engines, Rotors and other components teardown will be performed overseas with the supervision of AIB investigators.

 · Review of Bristow Helicopters Maintenance processes, culture and maintenance error correction program.