PPRuNe Forums - View Single Post - Super Puma down central North Sea Feb 2009
Old 28th Feb 2009, 19:42
  #320 (permalink)  
JimL
 
Join Date: May 2003
Location: Europe
Posts: 900
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Unlike some I have not yet seen the narrative of this accident however I feel obliged to comment on the thread and the appearance of a lack of awareness of existing limits from, what appear to be, experience flight crew. Let's deal with the ARA first:
Absolute limits are 300ft/night and 200ft/day with an additional proviso that the MDH cannot be lower than deck height plus 50ft (to provide a small cushion below the cloud base).
With an ARA to a circling manoeuvre, the limits are 300ft by day and 500ft by night. The MaPt is 0.75nm at which point, if the destination has not been acquired, a go-around must be flown (a reduced MaPt can be accepted if it provides equivalent safety).
The procedure with the OIP at 1.5nm 'should' provide some lateral clearance from the target even if the 'turning missed approach' procedure is initiated late. The segment from the OIP to the MaPt should be flown level.
If not on an ARA the cloud break procedure (en-route descent to VFR) by night requires a visibility of 5km and a minimum cloud base of 1,200ft and by day 1,500m and 600ft.

The geometry of the procedure is such that even with a 3 degree slope, the 0.75nm point will be at 238ft plus the height of the helideck; this almost inevitably ensures that there will be a level segment before visual manoeuvring to the deck occurs (unless the procedure is not flown as published). The geometry of the procedure was provided to ensure that there was an adequate time to transition from instruments to visual flying. Even so, normal crew procedures should ensure that at least one of the crew is monitoring the key instruments - even during visual manoeuvring (at night).

Any procedure must take account of the fact that there might not be complete visual contact with the perimeter lights if the deck is on the upwind side of the platform.

There is no freedom to fly below the VFR limits. The transition from IFR to VRF must be conducted either as an en-route descent with the VFR limits or as an ARA - in accordance with the published procedure.

The 'shiny arsed committee members' who were involved in the provision of the ARA did so at the behest of IFALPA and under the auspices of ICAO - they were all current offshore practitioners. The offshore VFR limits were also produced by a group of experienced pilots who understood very well the dangers of offshore flying both by day and by night (Northern and Southern North Sea, Norway and Holland).

I would suggest a toning down of the rhetoric as well as a period of reflection on both the accident (when details become clearer) and current requirements (as reflected in the Operations Manuals (OM)). It might also be useful to recognise that the Operator writes and owns the OM - not a faceless committee in Europe.

Any new SOPs must take due cognisance of the fact that not all fleets have the capability of the EC225 - the additional dangers of the human factors element of complex automation should also be part of any consideration.

Finally, with any point in space procedure there will be a visual manoeuvring element - not to understand that will lead the unwary into danger. There will always be the need for competent handling skills in helicopters unless you wish to operate only to airfields. Then what would be the point?

Jim
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