Aviation safety investigations & reports

Failure of main rotor system involving Sikorsky S92, VH-ZUQ, Broome, WA on 10 November 2016

Investigation number:
Status: Completed
Investigation completed

Final Report

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On 10 November 2016, a Sikorsky S-92A helicopter, registered VH-ZUQ, was scheduled to depart from Broome Airport, WA. During the start procedure, the flight crew reported feeling abnormal vibrations in the airframe. A member of the ground crew then showed the pilots an anti-flap stop that had broken off the main rotor head. Further inspection revealed that two anti-flap stops had been sheared off the main rotor head during start-up.

The anti-flap stop failure was a result of the collective not being lowered at the appropriate point during the start procedure. Several factors were found to have contributed:

  • A series of events resulted in the flight crew having more tasks to complete than originally planned, and less time in which to complete them. This resulted in time pressure on the crew.
  • The PM's unfamiliarity with the unique starting procedures in the S-92A compared with other helicopters contributed to the collective not being lowered in time.
  • The operator's standard operating procedures did not require any call outs for the lowering of the collective, which probably contributed to the collective not being lowered in time.

As a result of this serious incident, the operator conducted its own investigation, and produced 17 recommendations, including:

  • a review pf S-92A start procedures
  • more emphasis placed on the importance of lowering the collective within the engine start procedures
  • a review of certain aspects of flight preparation that contributed to the time pressure experienced.

This incident is an example of what can occur when pressure associated with on-time departures is compounded with the absence of clear operating procedures. It is important that pilots have detailed and specific instructions on which to fall back when they feel pressure beginning to build.

Part of Aviation Short Investigations Bulletin - Issue 60

Download final report
[Download  PDF: 199KB]
Alternate: [Download  DOCX: 331KB]

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General details
Date: 10 November 2016   Investigation status: Completed  
Time: 12:15 WST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): Broome    
State: Western Australia   Occurrence type: Propeller/rotor malfunction  
Release date: 24 May 2017   Occurrence category: Serious Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Sikorsky Aircraft  
Aircraft model S-92A  
Aircraft registration VH-ZUQ  
Serial number 920205  
Type of operation Charter  
Sector Helicopter  
Damage to aircraft Minor  
Departure point Broome, WA  
Destination Lombadina, WA  
Last update 14 November 2018