SAR Technology - Risk Management Service
Risk Management Planning -

Walking the Tightrope

Risk management in search and rescue is essentially a balancing act. When the search manager is asked to initiate a search he has been given the mandate to find and rescue the subject, for which the primary driving force is to reduce the degree of risk or harm to the missing person.

Contrarily, in order to meet the goal of reducing the risk to the subject, the search manager must generally, to some extent, put the search teams ‘in harms way’, as there is generally a greater or lesser degree of risk involved in deploying searchers into a mountainous or wilderness environment. Thus we have an inherent balancing act, as we have to weigh the level of risk we are willing to expose the searchers to, in order to reduce the degree of risk experienced by the subject.

A search manager tasked with conducting a SAR operation in a remote wilderness location is faced with a range of risk-management choices that will, ultimately, tend to put the desire to reduce the risk to the subject, who is generally considered to already be in a high risk situation, in direct conflict with those of the responders, who will have to be put into at least some level of risk, in order to conduct a successful search. From the outset it has to be recognized that there is generally always risk involved at some level in SAR operations, with the important question being, how can these risks be balanced and mitigated, while still conducting a useful and effective search?

Total Mission Risk

Risk management in search and rescue should be considered as a complete entity, as a Total Mission Risk, which includes not only the risks involved in deploying the searchers, but also the risk it is expected that the subject is experiencing. Classically the SAR response has primarily focused on the risk to the searchers “myself, my team, the subject”, in that order, but the very mandate of being asked to rescue the subject creates the necessity of including the risk to the subject in the equation of Total Mission Risk.

Traditional thinking has generally focused on reducing the risk to the searchers, as this is relatively easy to manage, rather than on reducing the risk to the subject, which appears to be unmanageable, as the subject is much harder to locate and hence, help. Nevertheless, in some limited ways, it is possible to reduce the potential or actual risk to the subject, which will then typically also reduce the risk to which the searchers will be exposed when they attempt to conduct a successful rescue. For example, placing signage, directional stringlines, using sound or visual attractors, are all techniques that can be used to encourage the subject to move from a higher risk environment, to a lower risk area. If the subject has been found but cannot be immediately rescued due to extreme terrain, poor weather conditions or approaching darkness, then dropping a survival kit, including clothes, food and a radio, can significantly reduce the level of  risk to the subject. Once the subject has been stabilized in this manner a rescue effort  can then be undertaken when conditions improve, providing a much safer rescue environment for the searchers. In this manner the Total Mission Risk can be significantly reduced for both the searchers and the subject. As discussed later the timing, number, sequence and the personnel skill mix of field team assignments can also be used to reduce the Total Mission Risk.

Loading the Scales

At one extreme of the search manager’s risk balancing act we could put the all searchers at very high risk, say with hundreds of searchers, of various skill levels, moving through steep and dangerous terrain. This would probably increase the chance of finding the subject, who is also exposed to this high-risk environment. Cleary the balance between putting hundreds of searchers into this high risk environment, to potentially save one person exposed to the same risk, is not reasonably balanced, as much of the Total Mission Risk is heavily weighted at the expense of the searchers.

At the other extreme of the risk balancing act all of the searchers could be asked to limit their searching to only low-lying meadows and valley bottoms, where they would be exposed to very little risk. This would certainly result in a much safer search, from the searchers perspective, but the subject, who is much more likely to be exposed to harm in the high risk, steep areas, would still remain at serious risk. The Total Mission Risk would have been significantly reduced – all the searchers would probably go home safely – but the balance would have been weighted heavily at the expense of the subject, who would absorb almost all the risk and, most probably, suffer eventual harm. Employing this overly cautious approach to risk balancing would probably fail our mandate to seriously attempt to try and rescue the subject.

The choices at the two extreme ends of the mission risk environment are reasonably clear. During a SAR mission in a mountain region with heavy recent snowfalls and avalanches occurring on a regular basis the decision is generally that everyone must ‘sit tight’ until the storm blows over and the snow has had a chance to stabilize. On a summers day, at low elevation in rolling hills, it might be considered quite safe to put all members of the SAR teams, including trainees and even members of the public, out to search the hills, as, at any time, they could all simply walk out, without real risk, to the nearest adjoining road. This would be essentially no different from anyone taking a short walk in the local woods.

The goal of the search manager should therefore be to balance the trade off between the risks he asks the searchers to accept with the expected benefit of significantly reduced risk, and hence potential harm, to the subject. Where possible every effort should be taken to identify and reduce the Total Mission Risk, by choosing strategies that can reduce the risks to either the searchers or the subject. These strategies do not necessarily require either that the searchers or the subject absorb a greater proportion of the risk, i.e. by simply adjusting the balance of risk, but can, preferably, reduce the overall Total Mission Risk.

Perspectives on Risk

Much of the thinking regarding our approach to risk comes from our backgrounds, our upbringing, the kind of recreation we enjoy, our age, sex, - males typically take much more risks than females, our family status – single, married, parents, and, of course, our personalities, which can range from the cautious and conservative, to the more thrill-seeking tendencies of ‘adrenalin junkies’. In this regard a disproportionate number of SAR responders fall into the latter category, with large numbers coming from the fire, police and ambulance services, as well as many climbers, skiers and large numbers of outdoor enthusiasts. Managing these generally thrill seeking, and often ‘Type A’ personalities, can be a real challenge for the search manager, who has to balance these energetic ‘go get ‘em’ attitudes - and their often quick burn-out rate, with the sustained and measured effort often required to resolve a long and technically challenging search.

At a more specific level SAR responders tend to fall into two general camps, those who come from a mountaineering background and those who do not. The former appear to accept more risks as being an intrinsic part of SAR operations while the latter, which generally also includes the responsible agencies, do not. An interesting part of the philosophy of SAR responders with a mountaineering background is that their approach to risk is not necessarily derived from an acceptance of increased risk, but from an understanding that risk can sometimes be reduced by what would be considered bold, or even risky, actions by their non-mountaineering SAR colleagues. A simple example would be the option, late in the evening, to bivouac on a wilderness mountainside to avoid darkness. If the forecast predicted an abrupt change in weather, with low cloud and rain, the SAR responders with a mountaineering background would probably be tempted to continue with the descent, to avoid the future risk of travel in bad weather, while their non-mountaineering colleagues might be tempted to bivouac and wait out the bad weather. In an alpine environment the former approach might well be the safer, although bolder, approach, while in the non-alpine environment the latter might be the safer approach. It all depends on how long the SAR team would have to wait in their bivouac site, how steep or vegetated the terrain was below and what the difficulty would be in navigating that terrain in bad weather. Experience over decades has taught mountaineers that speed and apparent boldness, i.e. the drive to move fast in a high-risk environment, is generally safer in the long run, than slow travel, which increases the exposure to actual risk from such objective hazards as storms, avalanches, rock falls and hypothermia.

Finding the Balance

The real difficulty in balancing off the risk-benefit issue comes in the gray area where there is some to moderate risk, much of which depends on the terrain, current weather conditions and varying skill levels of the available SAR responders. In general the higher the objective risk the greater the combined team skill level required to ameliorate that risk. For example, Himalayan climbing requires that all members of  the team have a very high skill level, to be able to travel relatively safely in the high-angle ice and snow environment. Searching in this high risk environment requires that all members of the team have a very high degree of skill. On the other hand searching grassy fields in a rural area may not require any major skills beyond basic navigation and clue protection. As such perhaps only one member of a larger team, say up to ten people, may actually require solid SAR skills for the team to be able to conduct an effective search. In this environment there is very little risk in searching the grassy fields with a high proportion of only slightly skilled, or perhaps even general public, personnel. Given that the more people deployed the greater the probability of finding the subject, the risk-benefit of employing primarily unskilled searchers in the grassy fields provides very little risk to the searchers while adding a considerable benefit, i.e. the significantly increased probability of finding the subject. Between these two extreme scenarios it seems reasonable to argue that field SAR teams should have an increased proportion of highly skilled searchers in the more difficult or dangerous terrain, and an increased proportion of less skilled and trainee members, including, if necessary, a high proportion of slightly skilled personnel and members of the general public, in the search areas of low risk. This approach maximizes the number of searchers, at all skill levels, that can be deployed, which increases the probability of a successful search and therefore reduces the risk to the subject, which is, eventually, directly proportional to the number of searchers deployed.

Unfortunately, unlike medical illness statistics and actuarial tables, there are few absolutes, such as defined risk probability factors for SAR, that we can use to balance the trade-off between the risk to the searchers and the resultant benefit, i.e. the level of risk reduction, to the subject. We do not have the data to determine that there may be, for example, a 1 in 5,000 chance of a broken ankle after 7 days of forest searching by 100 searchers. There are, however a few general rules that can be used to at least guide our decision making. The first is that risk will increase in direct proportion to the number of searchers deployed. Risk will also increase in direct proportion to the total time that these searchers are deployed. Therefore risk will increase in direct proportion to the total man-hours of search effort. In perverse but absolute contrast, the risk of harm to the subject will potentially decrease in direct proportion to the number of searchers and the total time that these searchers are deployed, as these factors directly increase the probability of finding the subject. In other words the acceptance of more overall exposure to risk by the searchers directly decreases the potential risk to the subject, i.e. the swing of the risk balancing act.

How can we balance these two diametrically opposing risk factors in a way that reduces the exposure to risk by the searchers, while improving the chances of successfully finding, and therefore reducing the risk, to the subject?

Reducing the Risk

The first factor to consider are the experiences of the mountain rescue community, who have long understood that objective risk can be reduced by minimizing the time and number of persons exposed to risk. In practical terms this requires fast and immediate action by small numbers of generally well-skilled searchers. This ‘hasty search’ technique has long been recognized as one of the most effective search techniques, requiring minimal manpower, to conduct a preliminary, but often effective, search. Under these conditions, in only moderately risky, non-alpine terrain, the search teams could be supplemented with a small proportion of somewhat less skilled members, e.g. trainees, to increase the probability of finding the subject.

The second technique requires maximizing the number of searchers deployed while the weather conditions remain favorable, i.e. safer. If a current spell of good weather is about to end then it is most probably safer, with less Total Mission Risk, to deploy as many people as possible, including lesser skilled searchers, into the search areas, before the weather begins to change for the worse. As the probability of detection is also much greater in good weather and clear visibility it is probably better to deploy all of the searchers, including the less skilled members, rather than deploying a smaller group of highly skilled searchers, who would not be able to cover nearly as much terrain. The probable outcome of the second option, although it might initially appear to be safer, would likely be an unsuccessful day’s searching and the need to then mount a major search the next day, with far more searchers, in much worse weather.  Clearly this would be a much more risky operation for both the searchers and the subject they are attempting to find.  In other words we cannot look at just the immediate risk of sending, say less skilled searchers into the field today, but we must also consider what would be the risk consequences in future days if we do not send these less skilled searchers into the field today. There is a high probability that this would soon lead, cumulating over the next few days, into a significant increase in the Total Mission Risk. Having to deploy large numbers of searchers for multiple days into even moderate risk environments, is, therefore, very likely to increase the Total Mission Risk. Ambulance attendants instinctively understand this when they are pre-stationed to respond to large-scale public gatherings, such as rock concerts, demonstrations or major-league sporting events.

Removing SAR personnel, as much as possible, from the highest risk environment is generally beneficial at reducing risk, of course, although it may be to the detriment, in terms of reduced probability of detection, to the subject. Helicopter searching is often an excellent way to remove the searchers from the areas of highest risk and also permits a fast response, reducing the chance of the search being overtaken by bad weather and it’s resultant risks. Deploying searchers in multiple helicopters, as soon as a favorable ‘weather window’ appears, has often been very effective at finding the subject, while removing much of the risk associated with having to deploy searchers, either immediately, or after over many days, into these moderate to high risk environments.

Tightly Coupled System

Another somewhat less obvious, but high risk factor, is the inappropriate use of ropes to provide the appearance, but not necessarily an actual, enhanced degree of safety for the SAR responders. Mountaineering literature is full of incidents of groups of roped climbers falling to their death, where one members slips and the others are unable to prevent the group from being pulled off the mountain at the same time. From Edward Whymper's ‘The Day the Rope Broke’ during the 1865 first ascent of the Matterhorn, to the 2002 three-person fatality on Mount Hood, including the subsequent crash of the  rescue helicopter. An unanchored rope, being used as a traveling belay by moving members of the team, can easily provide an illusion of safety that quickly evaporates into a ‘tightly coupled system accident’ when a fall begins. In practice, rope slack, hard snow conditions and the very brief time available to react, frequently result in the belayer being unable to hold the team against the considerable forces developed during the fall. It is therefore not surprising that SAR rope techniques, unlike their mountaineering equivalent, emphasize fixed belays and dual rope systems, to provide a relatively secure degree of rope safety. The general concern with rope-work is that unanchored or overly complex rope systems i.e. ‘tightly coupled systems’, can behave in unexpected and risky ways, that may affect more than one participant, and often the whole party, when sudden or unusual loads are applied.

Climbers, including searchers, traveling over dangerous terrain, can reduce the risk to the party by using either fixed rope anchors, or, where necessary, by traveling untied from each other, to reduce the chance of a one-person accident from becoming a multi-person tragedy. Traveling untied certainly appears to be, and is, a dangerous practice, but it may be less risky than putting the entire party under the illusion of safety, of what has been called a ‘suicide pact’, if they are tied together and moving in steep terrain where speed is required and no reliable fixed rope anchors are available.

Safety for the responding search teams can also be improved by making a close and careful inspection from the air, of the terrain in which the search teams will travel. During a major SAR incident it is recommended to first fly each of the primary search routes, carefully inspecting these route for potential hazards, documenting detours around the hazards and recording potential exit routes. Where possible digital pictures of the entire route should be taken and copies of these images given to the field teams during their safety and assignment briefings. During the actual search operation helicopter support may also be used to help guide and direct the search teams from above, as well as to provide additional supplies at designated landing zones.

The subject of the search may also benefit from the strategic deployment of the helicopter during team movements and searching operations. Experienced SAR pilots will fly each of their travel routes twice, once on the way out, and then again following the same route on their return. During the initial fly-over a subject hidden in the trees will probably hear the helicopter but may not be able to move to an open area in time to be seen by the passing helicopter. If the pilot then later returns along the same travel route, for example along a drainage system, then the subject will have had some time to move into the open and possibly be seen by the pilot and search crew returning along the same path. This technique involves very little additional risk to the search helicopter but is of considerable benefit to the subject.

Reducing the size of the search group, when following a route or trail, generally also reduces the level of risk to the party as a whole. A review of avalanches fatalities to two school parties in the Canada’s Selkirk mountains have resulted in recommendations to reduce the number of people traveling in each group, to both increase their traveling speed and to reduce the risk of a major, multi-person, tragedy. For both SAR responders and backcountry recreationalists, smaller parties are usually faster and therefore safer than large groups. Smaller parties generally have more collective wisdom than individuals, such as a subject traveling alone, and typically make safer, more rational, decisions.

Playing the Risk Lottery

Unfortunately small search parties, while safer for the searcher, also have a limited probability of detection and may not be successful in finding the subject. At some point, when these ‘hasty searches’ have been completed, the search manager will be faced with the decision of whether he should ramp up to a major, large-scale, search response. The implementation of the large scale search, involving large numbers of searchers over many days, are often considered to be the ‘last resort’ search option, as they are very manpower intensive and expose these large number of SAR personnel to increased risk. At some point this type of major search effort becomes essentially a ‘risk lottery’, whose risks can only be somewhat mitigated by stationing a medical response team ready for immediate deployment to assist either hurt searchers or the subject. This rapid response medical team will generally help to reduce, but only slightly, the Total Mission Risk. However, under the circumstances where all other search techniques have failed, a large-scale search is often necessary, as it is probably the only remaining search technique available for finding the subject.

Subject Survivability

After some period of time during an extended search the question will inevitably arise as to whether the risk of continuing the search outweighs the benefits of probably finding the subject alive. This is a crucial decision that soon becomes a major turning point in the determining the future level of effort, and the subsequent level of risk, to be accepted. A major factor in this discussion centers around how long the subject is likely to survive. A number of factors have to be taken into account when making this important determination. These factors include the nature and difficulty of the terrain, the daytime and nighttime temperatures, whether the terrain is dry and desert like, or cold, windy, with snow on the ground, blizzard conditions etc., The subject’s clothing, general health or any pre-existing medical condition are also important factors in determining their likelihood of continued survival.

Stories of survival frequently center around the subjects need to find water. This is a primary factor in deciding whether the subject is still likely to be alive. If the probability is reasonably good that water is available, even as snow, then there is a very reasonable chance that the subject could survive for a number of weeks, assuming they have not succumbed to injuries, falls, hypothermia etc. There have been very many cases where the subjects have easily survived for a week, in both summer and winter conditions, and often with very few ill effects. After being missing for only a week a great many subjects are still very much alive! Certainly a search should at least continue for perhaps two weeks or more, when the subject has probable access to water, or snow, and could make a shelter. Missing persons who shelter in tents, snow caves, bow-beds, lean to’s or other makeshift shelters can often survive for quite a long time, certainly into the weeks, especially if water and meager food sources are available. Too often there is pressure to shut down the search when the searchers initial enthusiasm has waned, which is often after about a week to ten days, despite the fact the subject could quite easily still be alive. The most common argument in favor of calling off the search after this time is a perceived lack of survivability of the subject, usually justified as being ‘too great a risk to the searchers’. This argument should be resisted as the subject, with water, could very easily remain alive for at least two to three weeks or longer.

Major Search Strategy

Given that a subjects survivability does eventually decrease with time, as does their detectability, either visually, or by movement, tracks, heat or sound, then the best approach to planning a successful search is to provide a major search effort immediately following the initial hasty search. The risk to the subject is minimized by this approach, as the subjects condition is generally better and their detectability by sight, sound, heat, movement and scent, are also generally greater. This greater detectability translates into fewer searchers being required to cover the same search area, in a shorter period of time, thus reducing the overall risk to the total search effort. In other words if the search is ramped up quickly there are greater benefits in terms of both increased subject detectability and fewer risks to the searchers, who are still alert and fresh. The subject, at this time, is also likely to remain in reasonable condition. This quick ramp up to a major search reduces the Total Mission Risk for both the subject and the searchers, compared to the slower, gradually escalated search, where the subjects condition will be steadily worsening, along with their deteriorating probability of detection. Ultimately the slower, gradually escalated search option would eventually require even more searchers for even longer periods of time. This slow escalation would be a considerably poorer search strategy that would create an increased and highly unbeneficial, Total Mission Risk.

Once it has been determined that the subject is no longer likely to be alive the search manager has to make the decision as to whether to call off the search or to continue it as a search for a deceased person. If the search is called off there are no longer any benefits for the subject, who is assumed to be deceased, and the risk is essentially reduced to zero for the searchers, who will not be deployed to any new search assignments. If the search is continued then the only remaining benefits are for the family of the deceased, whose pain and suffering could be reduced by the recovery of the subject’s body. Of course this benefit is substantially less than that of finding the subject alive. A such the risk balance should then be adjusted so that the searchers are exposed to less risk, as there is also less benefit now, only the reduction in the families sorrow, compared to that of finding the subject alive. Under these circumstances a search for a body is typically conducted in a more conservative and cautious fashion, where less Total Mission Risk, which would be entirely weighted onto the searchers, is considered acceptable.

Recovery Operations

If a body is found during the search effort, before or after the assumption that the subject would likely be deceased, then the search manager would probably use the same strategy, of reducing the risk to the searchers, to minimize the Total Mission Risk. If there are poor field conditions, such as limited daylight, bad weather or high risk terrain, the search manager may elect to postpone the body recovery until daylight or weather conditions improve, or until a more experienced field team can be deployed to the scene of the accident. This strategy, conducted after the body has been found, again reduces the Total Mission Risk, which is entirely borne by the searchers during a body recovery operation.


In summary it can be seen that risk is always present, to a greater or lesser extent, during search and rescue operations. However by considering the concept of Total Mission Risk we can balance the proportion of risk borne by both the searchers and the subjects, depending on the expected benefits at that time, especially when the benefit is still a live-person rescue. In addition to simply balancing the risks involved we can also employ planning strategies and field tactics than can reduce the overall Total Mission Risk. By employing these strategies and tactics we can eliminate the higher risk alternatives and employ techniques that can contribute towards a faster and safer search. The benefits of employing these techniques include a safer operating environment for the searchers and an increased chance of a successful live find of the missing person.  

  Risk Management Calculations
The example below calculates the approximate risk to a SAR responder in typical ground-search terrain.
It does not apply to other higher risk scenarios such as mountaineering or swift-water

Risk Terms: A micromort is a unit of risk defined as one-in-a-million chance of death from a day to day activity.
e.g. Rock Climbing = 3 micromorts per climb.

Mountain Hiking:           1 in 15,700 chance of death annually.
Recreational Climbing:  1 in 1,750 chance of death annually.
Assuming SAR activities have a risk factor half way between these two activities then...
Ground-SAR Activities: 1 in 8,725 chance of death annually (estimated).

SAR Responder's Individual Risk Calculation:
A SAR responders micromort (risk of death from a one day SAR activity) is an estimated 0.6 micromorts
from 3 x (1750/8725) = 0.6 micromorts or 1 in 1,666,666 per day of searching.
(This is slightly less risky than downhill skiing which is about 0.7 micromorts or 1 in 1,428,571 per day of skiing).
e.g. For 7 days of ground searching the Total 7-Day Risk to a single searcher is 7 x 0.6 = 4.2 micromorts or 1 in 238,095

Example SAR Total Mission (All Searchers) Risk Calculation:
For 15 ground searchers per day for 7 days
7-Day Total Mission Risk = (15 searchers x 7 days x 0.6 micromorts per day) = 63 micromorts.

Total Mission (All Searchers) Risk 
= (1,000,000/63) or 1 in every 15,873 missions of this size.

Setting a Total Mission Risk Limit
It is possible to decide on a preset Total Mission Risk Limit, for example 1 in every 10,000 missions of a specific size.
The total searcher-hours to reach that limit can then be calculated.
The mission's total searcher-hours are then monitored until they reach the calculated Total Mission Risk Limit.
This permits a pre-determined risk safety factor to be set for any mission of a specific size.


Copyright Martin Colwell,   SAR Technology Inc.

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