Jump to Content

Final Report

Summary

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

Read report

 
Share this page Comment