Improving offshore helicopter operability and safety

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Koning, J.
Reus, A. de
Zeilstra, K.D.S.
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Helicopter services have been used by the offshore industry for decades. Traditionally offshore production platforms were fixed. For drilling, installation and work-over, large and stable semi submersibles were deployed. Nowadays helicopters have to operate on FPSO’s, drillships and relative small well intervention and installation vessels. In countries around the North Sea, Civil Aviation Authorities (CAA) and helicopter operators are operating under a strict regime; for “small” vessels helicopters are only allowed to land and remain on deck if pitch and roll angles are less than 2° and the average heave rate of the largest wave is less than 1m/s for the last 20 minutes. MARIN technicians noted the sensitivity of offshore operations to these restrictions when they had to remain on standby at a Norwegian heliport for a week awaiting favourable landing conditions before flying to the destination vessel. The week wait sparked the incentive to investigate helicopter workability on ships and possibilities to extend that. A workability analysis for an 80 m light well intervention vessel operating offshore Norway, showed that the downtime for helicopter operations in winter time assuming good visibility may drop to 70 and 90% depending on the relative wave direction[1]. Helicopter availability is essential for an economic operation of these vessels as the alternative is to leave station and return to shore which can take days depending on the working area. The Helicopter Operations for Offshore Ships (HELIOS) project aims on decreasing the ‘downtime’ for offshore helicopter operations while at least maintaining the present safety standards. This is achieved by at first finding options to improve and optimize operations inside the existing standards and secondly by researching available “new technology” to increase safety and operability. Important conclusions are that: 1) Helicopter operability is dominated by “stability on deck” considerations. 2) Recent incidents suggest safety will be improved mostly by improving the pilot’s situational awareness during approach and landing. 3) Many technical solutions are available to improve safety and operability of the isolated stages in a helicopter operation. 4) A formal regulatory framework for helicopter ship operations is missing, so introduction of dedicated new technology can be done as it can be in the regular aviation world. 5) Actual introduction of technology requires technology pull from offshore oil companies in order to start certification procedures, enter trial and acceptation procedures with pilots and adopt new technology in the standing procedures. This paper highlights how safety could improve directly by increasing situational awareness during approach and landing and how operability could improve by raising on deck stability with deck lock systems and easing landing limits to the actual touch down limitations.