Thanks Peter - my questions were rhetorical to highlight the decision to take one course of action when a safer one might have been called for.
ANFI,
This is a point that should be addressed at the operator.
In the Alert Bulletin that has been issued by SAFRAN it is stated that:
"Subject to Service Bulletins Mo. 292 73 2166 and No. 292 73 3166, modification TU 166 is currently applied to new engines and upon first return of module M03 to a Repair Center on all ARRIEL 2 variants.
Modification TU 166 (SB No. 292 73 2166) is applied to the ARRIEL 2 variant upon receipt of parts sent to the operator during replacement of the HP turbine and an approved technician or upon first return to a Repair or Maintenance Centre.
Application of modification TU 166 is mandatory on the ARRIEL 2 single-engined fleet. We remind you that modification TU 166 on single-engine helicopters is overseen by our NORIA teams and is subject to Mandatory SB No. 292 73 3166 which requires TY 166 to be applied before November 18, 2012..."
There is an implicit assumption in this message that twin-engine helicopters operate with engine-failure accountability. If that is not the case, and it was not in this accident, isn't there an obligation on the Operator to apply the modification as though it were a single
or to ensure operations are flown in PC1 or PC2e?
There is a
hint of this in the report when it questions why the Approval to operate with Exposure was not withdrawn when the failure rate showed an alarming trend (probably exceeding the 1:100 000 reliability rate). That would have been rendered unnecessary with the application of TU 166.
The engine failure was the main cause of this accident; however, there is a chain of human factor precursors that turned what should have been a heart-stopping moment for crew and passengers into a fatal accident (to crew and passengers).
When the IHST and EHEST started their work on re-analysing accidents, it confirmed the fact that the largest proportion of accidents were Human Factor related. That is the reason why EHEST integrated HFACS into their list of contributory causes.
I'm still astounded that this is a sleeping thread; is it because it is easier to comment on a R22 rescuing a radio controlled plane than read an accident report and question matters which are germane to continuing health in offshore operations.
Mars