This is not the first helicopter type to get airborne inadvertently (happened on the EC225, which has a collective lock, the S76 as already mentioned, and even the Bell 212 which does not have a parking brake!).
The S92A Rotor Head is fitted with elastomeric bearings. Without hydraulic pressure the collective will rest in a mid-range position. Despite a Note in the RFM this has not prevented the helicopter
'jumping the chocks' during single pilot engaged rotor ground runs by several S92A operators, until the appropriate SMS training corrected the error of not lowering the collective as hydraulic pressure builds.
Thus a collective lock cannot be fitted to the S92A.
The operator did not have a policy of covering the collective lever whilst applying the Parking Brake on the S92A, and following this incident a Global Standard has now been adopted on all helicopter types.
Originally Posted by coning angel
From the story I heard last night, they were lucky!
You were obviously told the story
'send three and four pence we're going to a dance'. The actual story was
'Send re-enforcements we're going to advance'