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Investigation of helicopter incident - proposed measures to improve safety

The Petroleum Safety Authority Norway (PSA), assisted by the Civil Aviation Authority (CAA), has prepared a report in connection with the investigation of an incident in which the tail section of a helicopter got caught in the rope net on the helideck of the Transocean Searcher in January 2004. To stimulate improved safety for helicopter transport on the Shelf, the report describes cooperation issues linked to Statoil, Transocean and Norsk Helikopter (NHS) which can be improved.


The report deals with the helicopter incident in which the tail guard got hung up in the rope net on the Transocean Searcher on 8 January 2004. Statoil was the responsible petroleum operator, while Norsk Helikopter (NHS) supplied the transport services. The Transocean Searcher is owned and operated by Transocean.

There were no personal injuries nor damage to the helicopter in this incident. The rope net on the helideck was severely stretched. However, in the opinion of the PSA, the incident could have had significant safety consequences as the pilots could have lost control over the helicopter.

PSA follow-up
The PSA originally elected to investigate this incident simultaneously with two incidents linked to the Ringhorne facility; one wrong landing (6 November 2003) and one near wrong landing (19 January 2004), as all three of the above-mentioned incidents fell under the PSA's formal sphere of responsibility. With reference to the cooperation agreement between the PSA and the CAA, provisions were made for the CAA's assistance in the investigation.

During the process, the agencies concluded that two reports should be drawn up; one based on the incident on the Transocean Searcher and one based on the two incidents en route to/at Ringhorne. This work was completed in June, and the investigation report has been published on the PSA's web site.

General perspective
The report now made available has a broader perspective than the helicopter incident on the Transocean Searcher, since the PSA has also evaluated other helicopter incidents in order to be able to assess which issues may be of a more general character for helicopter transport on the Shelf.

The report also covers the course of events and failure causes involved in the incident, as well as discussions in relation to the interface between the PSA's and the CAA's spheres of responsibility. In some cases, the report also deals with factors that lie outside of the PSA's formal sphere of responsibility. This was necessary in order to be able to investigate the incident and its underlying causes in an overall context.

The report describes observations that relate to Statoil, Transocean, NHS, the authorities and the industry in general. It will also be sent to the CAA and OLF (the Norwegian Oil Industry Association) with a view towards further follow-up. As the report focuses on regulatory matters and general challenges for rig owners/drilling contractors, the report will also be sent to the Norwegian Maritime Directorate and the Norwegian Shipowners Association.

It emerges from the enclosed report that the Accident Investigation Board for Civil Aviation and Railways (HSLB) is investigating this incident - and the report is therefore also being sent to the HSLB. The PSA recommends that both investigation reports linked to the incident on Transocean Searcher be subjected to discussions and evaluations with a view towards improving helicopter safety on the Norwegian shelf.

Underlying causes
The report identifies examples indicating that risk analyses can be used in a more comprehensive and systematic approach so as to reinforce the basis for making decisions. This can apply to systems or solutions that are to strengthen the human, technical or organizational (MTO) factors as barriers. Acceptance criteria should be used when evaluating the analyses.

In incident investigations including helicopter incidents, the underlying causes linked to MTO factors should not only be examined in the specific incident situation. It emerges from several investigations that neither the helicopter contractors, petroleum operators or rig owners seem to search far enough back in the chain of events.

The helicopter contractors, rig owners and petroleum operators should intensify the focus on near-misses where failure of barriers dominate. It may be just as important to investigate this type of incident as incidents that have actual consequences. The challenges in these contexts seems somewhat greater on the part of the helicopter contractors than with the petroleum operators and rig owners. The consequence of this could be that underlying causes are not identified.

Transocean did not investigate the incident on the Transocean Searcher, nor did it participate in the investigation carried out by the helicopter operator. Since Statoil did not conduct an independent investigation, but chose to participate in NHS' investigation, there were no provisions for employee participation in the process.

The investigation revealed that there is a potential for improvement in the system for transfer of experience and information between the involved companies. This relates to enhancing the level of competence and improving safety.

It emerges from the report that the communication between the helicopter crew and the helideck personnel was not adequate, taking the incident into account.

The investigation showed that recording and measurement of weather and motion data can be improved as a basis for satisfactory route reports and planning of the helicopter transport.

The PSA believes that safer helicopter transport can be achieved if this topic becomes a more distinct element in the drilling contract, so that the rig owner bears more responsibility for following up the petroleum operator's HSE objectives in connection with the helideck and helicopter transport.

Examples of measures
In this investigation report, the PSA has mentioned examples that are intended to be input for discussion of alternative solutions/measures. This is not common practice. The intention of this departure from common practice is to stimulate improvements in helicopter transport on the shelf in an overall context.

The proposed measures deal with the following areas in a general perspective:

  1. The industry's guidelines and procedures should be evaluated, in part in connection with risk analysis and risk management, transfer of experience, follow-up in design and operations/maintenance, and factors linked to obtaining and using weather observations.
  2. The petroleum operator, rig owner, helicopter contractor and interaction among these parties should be considered, including as regards factors linked to flow of information between the helicopter contractor and operating company/shipping company, need for expert helicopter competence, motion data requirements on the facility, need to develop the MTO aspect in connection with investigations and focus on HSE in contracts.

Chapter 10 of the report provides a detailed overview of the proposed measures.

The PSA asks Transocean, Statoil and OLF to provide a written response to selected sections of the report by 30 August 2005.

Contact in the Petroleum Safety Authority Norway:
Inger Anda, press spokesperson
E-mail: inger.anda@ptil.no
Tel.: + 47 970 54 064