An overview of the outputs from the SJA is given in Table 1. In the SJA, we systematically review the offset rescue technique by dividing the work into tasks and reviewing each task, to assess the hazards associated with it. In Table 1, the offset rescue operation is split into the following five sub-tasks:

1.

Reconnaissance

2.

Leaving the rig site and arrival at the scene

3.

Preparation of patient

4.

Leaving the scene and evacuation, underslung, by the helicopter to the rig site

5.

Retrieval of climber(s)

These sub-tasks are the same tasks highlighted in the procedure for the offset technique.

The results from the SJA are based on feedback from five pilots, four HCMs and five emergency physicians. The crew member composition includes highly experienced to less experienced crew members. The dialogue with the different crew members was organized by the authors, consisting of a professor in risk management together with a subject-matter expert HCM and an emergency physician.

Before the dialogue with the different crew members on potential hazards for the different steps of the offset technique, we organized some training sessions related to static rope evacuation. A full training session included (1) a traditional static rope rescue operation with a 30-m and a 60-m rope, (2) an offset rescue technique with a 30-m and a 60-m rope, and (3) an offset rescue technique in really steep terrain, using a 60-m rope. All the training scenarios with the use of the offset technique were conducted in complex terrain, requiring the double attachment procedure [8]. All training missions were conducted in accordance with approved procedures, limitations and risk analysis for static rope rescue missions.

Some crew members did all five training runs, but some only participated in some of the runs. All the crew members that gave input to the SJA participated in at least one of the offset training runs.

In the risk analysis, we focus only on potential hazards associated with the offset rescue technique. Attention is not given to the risks of the different hazards identified. The reason for this must be seen in relation to the aim of our study, whose focus is on the procedure for the offset rescue technique and an evaluation of the same. We then need to gain insight into the extent to which different identified hazards are eliminated or considered, in the way the procedure is described. The classification and categorizations of risks for the identified hazards are then not relevant, given the main aim of our study.

It can be pointed out that hazards which are solely of theoretical interest are omitted from the analysis. This is to avoid making changes to the existing procedure to avoid hazards that are solely of theoretical interest. All the results are shown in Table 1. The main findings from the analysis are given below and categorized for each task of the offset rescue operation.

Sub-task 1: reconnaissance

In the reconnaissance phase, a choice is made as to how the rescue operation should be executed. When deciding upon evacuation by the use of a static rope, one must decide on the length of the rope to be used—one which provides the pilot with good visual references—and, further, on the type of evacuation procedure to be used—the traditional one or the offset technique. Based on the SJA, the choice of rope length has been identified as being more critical when using the offset technique than when using the traditional underlying rescue operation. Two main arguments for this were identified. In an offset rescue operation, a too short rope may contribute to the HCM not reaching the scene. This may happen as the rescuer cannot make ground contact given the helicopter’s offset location. There may also be situations where the length of the rope is sufficient in itself but where the HCM still cannot get to the scene, as dragging him/her to the scene proves too heavy for the climber. To make the work for the climber less heavy, the flight height must be reduced, which is not necessarily possible due to the terrain. This was identified as a problem in one of the training runs.

Sub-task 2: leaving the rig site and arrival at the scene

Compared to the traditional static rope evacuation, it is the arrival at the scene that is different when using the offset rescue technique. During the traditional static rope evacuation, the HEMS crew can arrive at the scene directly. When using the offset technique, you need help from a person at the scene to establish this contact. This can be done with help from volunteer rescue climbers, a person close to the patient or the patient him/herself. In this step of the offset technique, several hazards may occur, as shown in Table 1. Most hazards will just lead to more time being spent before reaching the scene and thereby more time spent before evacuation of the patient can start. But, without the offset technique, one could not gain access to the patient from the helicopter.

From Table 1, we see that there are some situations that may arise during offset operations that affect the safety of the crew members. First, one safety issue which might occur is if the HCM does not complete a final check of his/her personal protection equipment, i.e., harness, attachment to static rope or offset throw line. This hazard is very unlikely to occur, due to the established checklists, safety barriers and routines before a rescue mission is executed. Second, there is a risk of the helicopter being positioned too close to the terrain, which might pose a serious hazard for the whole helicopter crew. During a rescue mission in cooperation with climbers, rappel ropes might also pose an additional hazard for the helicopter. Third, there is a risk of the offset throw line accidentally becoming entangled with a fixed object at the accident site. The weak link on the throw line is designed as a safety barrier if this should occur.

Sub-task 3: preparation of patient

In the offset technique, the helicopter and the HCM may lose contact with the scene. This will happen if the rescuer disconnects from the helicopter during the offset operation. This should not be done, as is clearly described and specified in the procedure for the offset technique. This aspect should also be highlighted in the briefing between the crew members before an offset rescue operation starts.

In addition to this, by using the offset technique, one will sometimes end up in a situation where the HCM is connected to both the helicopter and to the scene at the same time, due to complex terrain and use of the double attachment procedure. Critical situations may then arise if the helicopter is not able to maintain a steady hover. This might also be a hazard in a traditional static rope evacuation when using the double attachment procedure. Should this emergency occur, the helicopter has the possibility to disconnect the rope from the helicopter, hence allowing for a fly away. Disconnecting the rope from the helicopter represents a serious hazard for the HCM hanging at the end of the rope and is only to be used in an emergency as a last option.

Sub-task 4: leaving the scene and evacuation, underslung, by the helicopter to the rig site

Using the offset technique, the HCM and patient can leave the scene autonomously using a controlled pendulum. If using the short tag line when leaving the scene, there is a need for a climber to control the free-running Munter hitch.

In cooperation with climbers, it is important that the climbers are thoroughly briefed on the offset technique in advance. In one of the training runs, where a controlled pendulum was not possible due to obstacles in the evacuation axis, a situation was identified where the climber did not follow the offset procedure: he/she did not control the Munter hitch on the short tag line when the HCM was leaving the scene, allowing for a pendulum. There can be several reasons why one does not follow the procedure. One reason could be that the climber was not thoroughly briefed in advance. Another reason is that the extent of the job task itself is complex, which contributes to difficulties in following the procedure as intended. A third reason is that one does not fully understand what was conveyed in the briefing. The procedure in itself is not difficult, but we discover that it can be fruitful to explain during the briefing not only what to do but why things should be done as described in the procedure. A fourth and probably most likely reason is that most climbers are not used to operating in a helicopter rescue environment. This has been observed in several similar situations and might have affected the overall stress level of the climber, allowing for an adverse event to happen.

During the risk analysis workshop, it was highlighted that the use of the short tag line is of special importance if obstacles are present when leaving the scene and in the evacuation axis (e.g., a canyon/gully), underslung, by the helicopter to the rig site. Without the use of the short tag line, there will be a risk of a strong pendulum movement when the HCM and the patient leave the scene, which may have an impact on the safety of both the rescuer and the patient, due to the terrain.

Sub-task 5: retrieval of climber(s)

After leaving the scene and evacuation, underslung, by the helicopter to the rig site, one needs to retrieve the climber(s). This can be done by using the offset technique or by the climbers themselves. What happens after having flown out of the scene with a patient will not have an impact on the offset procedure. All hazards that may occur during a possible retrieval of the climber(s) will be taken care of by conditions that are covered in the sub-task ‘Leaving the scene and evacuation, underslung, by the helicopter to the rig site’.