This accident and others during the 1990shighlight a troubling trend where knowledgeabl(avalanche aware) people made decisions thatended in a negative outcome. In fact thisaccident shares many common themes (steepslopes, fresh snow, signs of instability, norescue gear, etc.) with other avalancheaccidents. Every year these same themesreoccur. Only the names of the victims change.It has been said in aviation that there are no naccidents, only variations upon reoccurringthemes (Braithwatie, 1999). This samestatement can be said about avalancheaccidents.

It is well established that avalanche victims aregenerally their own worst enemy. Nine-in-tenavalanche victims (or someone in their group)trigger their own avalanche (McCammon, 2000Atkins, 1994; Logan and Atkins, 1996). Thesame mistakes are being made repeatly (Fesle1980; Fesler and Fredston, 1984; Atkins, 1994Most avalanche accidents can be prevented(Fesler and Fredston, 1984; Logan and Atkins,1994). Because the same mistakes are beingrepeated this implies there are no newavalanche accidents, only variations uponrecurring themes.

"This was inappropriate and irresponsiblebehavior... it was dangerous to myself and

.others."

McCammon (personal communication, 2000)recently reviewed avalanche accidents in theUnited States (1980 to 1986) and in Canada

. (1984 to 1996). He found "In recreationalaccidents where the group had prior avalanchetraining, a stunning 89% had evidence thedanger was high." Furthermore he found adisturbing statistic: "Only 46% of these groupS

46

"Life is short, the art long,opportunities fleeting, experiencetreacherous, judgment difficult."

- Hippocrates

1. INTRODUCTION

On January 22, 1999 a 45 year-old Aspen,Colorado man was buried and killed in a verysmall avalanche he triggered outside of theAspen Highlands Ski Area. The night before theaccident the victim and a friend spoke aboutskiing the backcountry outside of the ski areabut agreed the avalanche conditions were toodangerous. The backcountry avalanche dangerwas rated "high" and a warning issued by theColorado Avalanche Information Center was ineffect. They decided to leave their transceiversand shovels at home. The next day the lure offresh powder led the victim to venture outsidethe ski area. He completed two runs andexperienced extensive instability with shootingcracks and collapsing snow. For his third run hisfriend (from the night before) joined him. Neitherman carried avalanche rescue year. Afterleaving the ski area boundary both menexperienced shooting cracks and collapsingsnow. They triggered a small soft slabavalanche that buried the victim. With no rescuegear it took almost an hour to find the man.Twelve days earlier the victim had been caughtskiing in a closed avalanche area. Four daysbefore his death the local newspaper publisheda "public apology" written by the victim.Regarding skiing in a closed avalanche area, hewrote:

ABSTRACT: A review of fatal United States avalanche accidents in the 1990s shows terrain, weather,and snow pack conditions are generally contributory factors to fatal avalanche accidents; human factorsare the primary factor. Human errors are made in terms of judgement, skills, and knowledge. This paperdiscusses the human factors and errors that might mitigate decision-making errors. The relevantinformation for this study came from 10 years of accident reports, media reports, and interviews collectedand compiled by the Colorado Avalanche Information Center. By identifying and understanding thedynamics of human errors perhaps new or improved pedagogical tools and/or procedures can bedeveloped in improve the safety of people in avalanche terrain.

KEYWORDS: Human factors, human errors, avalanche fatalities, avalanche accidents, naturalisticdecision making.

Dale Atkins *Colorado Avalanche Information Center, Boulder, Colorado

HUMAN FACTORS IN AVALANCHE ACCIDENTS

* Dale Atkins, Colorado Avalanche InformationCenter, Boulder, CO 80303; tel: 303.499.9650;fax: 303.499.9618; email: caic@rmi.net

with prior avalanche training took pre­cautions ...."

Another clue supporting human factors cor,nesfrom the results of a recent survey by Jamiesonand Geldsetzer (1999). The pair surveyedexperienced avalanche workers about. .unexpected skier-triggered avalanches I~phes

weather and snowpack are n?t ~ecessarllyprimary factors in avalanche incidents.

The literature and basic research s~owsavalanche accidents are not a terrain: weather,or snowpack problem; avalanche accIdents area human problem.

Since avalanche accidents are a humanproblem it begs the question of not "How" but"Why do avalanche-aware people let themselveshave avalanche accidents." This question is notnecessarily new. Fesler (1980) asked a similarquestion; his solution focused on route selection.The differences between how and why mayseem minor, or unimportant, but how and whyare not synonymous. How refers to the manneror cause, e.g., "How did the airplane crash?"The airplane flew into the ground, or 'Whatcaused the avalanche?" The victim traversedonto a steep, wind-loaded slope. Why refers tothe purpose or reason: Why did the pilot fly intothe ground, or why did the skier enter the steep,wind-loaded slope? The answer can likely befound in the cognitive skills (informationprocessing) of the victims.

2. DISCUSSION

2.1 Naturalistic Decision Making

To determine the nature of decision-makingerrors in avalanche country by avalanche-awarevictims I have considered that avalanchedecision-making is a type of "naturalisticdecision making" (Klein, 1998; Orasanu andMartin, 1998).

~n ~~turalistic decision making (NOM) anIndIVIdual has some level of domain expertise inreal world context. Their context involves limitedtime,. dynamically changing conditions, goalCO~fll?!s, and information sources of varyingreliability. NOM usually involves recognizing aproblem, evaluating the situation to define thenatu~e of the problem, and determining aSOlutIO~. Additional options may be consideredbut their evaluation is typically not exhaustive(Orasanu and Martin, 1998; Klein, 1998).

47

Naturalistic decision-makers tend to "satisfice,"or chose a solution that meets their needs(Simon, 1956; Orasanu and Martin, 1998).These decision makers act according to theirunderstanding of the situation, and the source oferror is the decision maker's knowledge base orin the process of reaching a decision (Orasanuand Martin, 1998)."

2.2 Potential Problems and Caveats

For the accident evaluator identifying errors innaturalistic contexts can be difficult for tworeasons (Orasanu and Martin, 1998). First thereis often not a single "correcf' or "besf' solution,e.g., mountain climbers choosing to move or notmove during a storm. Second, outcomes are notalways reliable indicators of the quality of thedecision. In some situations even the bestsituation will be overwhelmed by conditions thedecision-maker has no control. Besides thedifficulty of recognizing errors there somecaveats about the following results that must betold.

Avalanche accidents are infrequent; follow upinvestigations and reporting are even lessfrequent. The sample size of avalanche accidentreports is very small. Accidents if investigatedare investigated differently in different regions,and avalanche accidents are usuallyinvestigated by an individual rather than by acommittee. Personal biases can creep intosingle-investigator reports. There are no checksand balances for the interpretation of the data.Also there are no clear working definitions forthe concepts of human factors in avalancheaccidents, so some latitude must be consideredwhen examining these results.

3. RESULTS

During the 1990s there were 190 reported fatalavalanches that killed 234 people. Of thosekilled varying amounts of demographic andpersonal information were known on 217victims. Of these victims some information aboutthe skill level and avalanche awareness level of82 victims was also known. Of these victimsavalanche-aware victims were involved in only41 fatal accidents.

"Good jUdgment comes fromexperience, and experiencecomes from bad judgment."

- Barry LePatner

10 15 20 25 30 35number of accidents with known cau...

25

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2015

number of accidents

10

skill

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IJ!.F'IW

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Figure 2 shows judgment is the most commonhuman error made in avalanche accidentsinvolving these avalanche-aware victims. Thepattern and values are similar to those found inthe aviation industry. (It can be assumed thatuntrained victims would have a reversed trendwith knowledge as the significant human errorfollowed by skills and judgment.)

I judgement Ps••EmJm_._._.26

I ~

! 2 knowledge IB--, ~

C~

I.' ~no em><

Working definitions for these human error typeswere taken from Webster's Dictionary:• Judgement: the ability to come to opinions

things.• Knowledge: all that has been perceived or

grasped by the mind: understanding.• Skills: ability in such an art, craft, or science

accidents but are the primary factor in fatalaccidents (figure 1).

Figure 2. Human errors in fatal avalancheaccidents, 1990/91 to 1999/00 (n=41).

Figure 1. Primary factors causing fatalavalanches, 1990/91 to 1999/00 n=41).

It is important to note from figure 2 that in fivecases there was no apparent error. In otherwords the victims (or groups) were makingnecessary and appropriate decisions andprecautions and still got into trouble. These fivegroups were the four involved in terrain-causedaccidents (climbers on technical routes inAlaska) and one group of skiers in a snowpack­caused accident (see figure 1). Dealing withavalanches is dealing with uncertainty and

48

0% 0% 40%

0% 1% 32%

9% 5% 12%

novice intermediate advancedActivity Skill Level

Table 1 shows that 73 percent of the victimskilled during the 1990s had at least someavalanche awareness training, and many victimshad a considerable amount of avalancheawareness training. This is consistent with the70 percent of backcountry victims found byMcCammon (2000) to have possessed at leastsome avalanche awareness training.

Table 1. Relationship between avalanche­awareness training and activity skill-level ofbackcountry travelers, U.S. avalanche fatalities,1990/91 to 1999/00 (n=82).

3.1 Skills and Knowledge

A review of fatal avalanche accidents involvingavalanche-aware victims in the 1990s showsthat human factors are not just a contributor to

3.2 Human Factors and Errors

For the purpose of this study I defined "some" ashaving attended at least one evening-typeawareness program and/or having someinformal training with friends while traveling inthe backcountry. Books or videos sometimessupported this training. The "advanced" levelrequired at least three seasons of recreating orworking in avalanche terrain along with theattendance of several awareness-type programsor the attendance of at least one multi-daytraining program. Again books or videossometimes supported this training. It is importantto point out that using these criteria does notimply competency at the "advanced" level. Insome fields (medicine, engineering, chess,music, etc.) an individual with only three or fouryears of experience is often considered a noviceMyer, 1992).

Table 2. Human factors, Fredston and Fesler,1994.

sometimes accidents will happen to the best

trained.

The role of human factors in avalancheaccidents is not new. Fesler and Fredston(1994) introduced the concept and now manyavalanche awareness educators includemention of human factors in their training.Fredston and Fesler noted 15 different humanfactors (table 2) that were major contributors toavalanche accidents:

7+

1916

50 r----------------~45 . 43

40

35:l~ 30

~ 25 21

~ 20

.:! 15

number of fatal accidents increases when groupsize consists of seven or more members. Itshould not be construed that small groups (2 or3 individuals) are the most dangerous. Groupsof 2 or 3 are probably the most common size forgroups heading into the backcountry.

Research in risk taking show that small groupsof 2 or 3 are more cautious than an individual(Wilde, personal communication). However,large groups are more risk accepting-known asthe "risky shiff' (Stoner, 1968) or less risk-awareresulting in greater danger to the group.

10

- laziness- money considerations- poor planning- tunnel vision- peer pressure- poor communication- fatigue

-attitude-money-ego-denial-indecision-haste-complacency-summit fever

A review of the 41 fatal accidents involvingavalanche-aware people during the 1990sproduced a smaller list (figure 3) presents asimplified list of human. Several factorsidentified by Fredston and Fesler (e.g., ego,denial, haste, and summit fever) are actually theresult or consequence of attitude. The categoryof attitude can be further sub-divided into threesubclasses: (a) anti-authority, (2) impulsivity,and (c) invulnerability.

party size

Figure 4. Frequency of fatal accidents comparedto party size, 1990/91 to 1999/00 (n=146).

Lastly, from figure 4 one might infer that whensmall groups (2 or 3 people) have an accidentand one person is buried there are too fewpeople to effect an efficient rescue.

4. CONCLUSION15

pooreorrmunication

r'IOerrOl' ~~~~~ .J

attitude ;'Eil1i__:'_B1l12j __agement

i cemplacency~

When investigating avalanche accidents themost consequential question is not one of slopeangles,snowfall, winds or weak layers, but oneabout the victim's cognitive skills: 'What

To prevent avalanche accidents and to savelives there needs to be a better understanding ofthe dynamics of human errors and how theylead to accidents. To achieve this knowledge weneed to improve accident investigation andevaluation methods and techniques.

Human factors are the cause of most avalancheaccidents involving avalanche-aware people.Staying alive is not as simple as being able torecognize avalanche hazards. The problem isseldom a lack of information regarding terrain,weather, and snowpack. The problem is howthat information is processed. However,sometimes even the best decision or solutionwill be overwhelmed by conditions beyondhuman control.

49

201612number of inatanC*S

rigure 3. Frequency of human factors identifiedIn avalanche accidents involving victims withsome or advanced levels of avalancheawareness training. (n=41. Responses total~o~e than sample size due to some accidents

aVlOg mUltiple factors.)

3.2 yroup Size

~rger gro~ps are more difficult to manage into~hmountarns ~nd. woup size may be important

e safety of Individuals. Figure 5 shows the

L

Association for Search and Rescue. Chantilly,VI.

Apter, M., 1992. The Dangerous Edge: The .Psycologyof Excitement. New York. The FreePress.

Beighley, M., 1995. Beyond the Safety Zone:Creating a Margin of Safety. Fire ManagementNotes. Volume 55, Number 4. 21-24.

Braithwaite, G. 1999. "Shaken but not Stirring?The 'need to know' basis of aviation safety."Australasian Regional Air Safety Seminar.

Fredston, J., and D. Fesler, 1984. Snow Sense:A Guide to Evaluating Snow Avalanche Hazard.1st ed. Alaska Department of Natural ResourcesDivision of Parks and Outdoor Recreation.Anchorage, AK. 48 pp.

Fredston, J., and D. Fesler, 1994. Snow Sense:A Guide to Evaluating Snow Avalanche Hazard.4th ed. Alaska Mountain Safety Center,Anchorage, AK

Fesler, D. 1980. Decision-making as a functionof avalanche accident prevention, Assoc.Committee on Geotechnical Research, NationalRescearch Council, Canada, TechnicalMemorandum 133, Ottawa, Canda, 128-136.

Klein, G. 1998. Sources of Power: How peoplemake decisions. The MIT Press. Cambridge,MS. 320 pp.

Laudan, L. 1994. The Book of Risks: FascinatingFacts About the Chances We Take Every Day.New York: John Wiley & Sons, Inc.

Logan, N. and D. Atkins. 1996. The SnowyTorrents: Avalanche Accidents in the UnitedStates, 1980-1986. Colorado Geological SurveySpecial Publication 39. Colorado GeologicalSurvey, Department of Natural Resources.Denver, Colorado. P. 234.

Mayer, R. 1992. Thinking. Problem Solving.Cognition. 2nd ed. New York: W. H. Freemanand Company. 387-417.

McCammon, I. 2000. The Role of Training inRecreational Avalanche Accidents in the UnitedStates. Proceedings of the International SnoWScience Workshop (in pUblication,) Big Sky,Montana.

50

5. REFERENCES

Lastly, overconfidence is a major human error inavalanche accidents (figure 4). People generallyover estimate their ability to recognize risks, orthey over estimate their ability to handleproblems if an accident should occur.Fortunately teaching people to reduce theiroverconfidence is easy, but it is seldom done inavalanche education. Instructing individuals orgroups to stop and consider reasons why one'sjudgement might be wrong can reduceoverconfidence. (Pious, 1993; Koriat,Lichtenstein, Fischoff, 1980)

By identifying and understanding the dynamicsof human factors perhaps new or improvedpedagogical tools and/or procedures can bedeveloped in improve the safety of people inavalanche terrain.

• What do people know?• What do people think?• What do people do?

It will take time to learn more about humanfactors in avalanche accidents, but fortunatelythere are already several techniques used bythe aviation industry, fire fighting and militarythat we can adopt to mitigate human factors anderrors in avalanche accidents..

One is to increase experience and situationalawareness by training to recognize human-errortrends so to prevent an accident from occurring(Orasanu and Martin, 1998). Another techniqueis to use mental simulations so decision makerslearn to consider options, the disadvantages oftheir selected outcomes, and the likelihood ofvarious outcomes (Orasanu and Martin, 1998;Klein, 1998). This requires more role-playing orsmall-group exercises in avalanche education.These exercises should even be included in themost basic awareness talks.

Atkins, D. 1999. U.S. Avalanche Deaths in the1990s, Part I: Trends. National AvalancheSchool. Incline Village, Nevada.

Atkins, D. 1994. Report of the United StatesDelegation to the International Commission forAlpine Rescue. Gieranger, Norway. National

interfered with the person's judgement at thecrucial moment." Australian aviation accidents'expert Graham Braithwaite suggests the need todiscover:

Phillips, K. 1996. "Keeping the Skies Safe: AnExamination of Helicopter Rescue Accidentsand Safety." Colorado Search and RescueAcademy, Granby, CO.

Rinn, E. 1999. "Aviation Accidents." TransportCanada. Canadian Avalanche AssociationWorkshop for Mountain Professionals. May, 7.

Siovic, P., Fischhoff, B., and S. Lichtenstein,1979. "Rating the Risks." Environment, 21, 14­20,36-39.

Stoner, J. 1968. Risky and Cautious Shifts inGroup Decisions: The influence of of widely heldvalues. Journal of Experimental SocialPsychology, 4, 442-459.

Taylor, J., Stewart, T. and B. Downton, 1979."Perceptions and Drought in the Ogalla AquiferRegion." Environment and Behavior, 20(2), 150­175.

Tobin, G., and B. Montz, 1997. Natural Hazards:Explanation and Integration. New York: TheGuliford Press. 388 pp.

Sullivan, C. 1999. "A Systemic Investigation ­Where Do We Start?" Australian and NewZealand Society of Air Safety Investigors.Queensland.

Wilde, G. 1994. Target Risk. Toronto: PDEPublications. 233 pp.

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