CASM v3.0 is a proposed Human Factors tool which is based on Crew Resource Management (CRM) training from the aviation sector. Established research into avalanche incidents and the applied psychology of Human Factors in safety critical industries have both formed the basis of CASM.

Guides, instructors and leaders operating in the UK in avalanche terrain frequently travel in groups, but yet there remains very little research into the ‘Non Technical Skills’ required to mitigate avalanche terrain. CASM is described here through the lens of work in avalanche terrain, but the concepts will be useful in may contexts summer or winter.

CASM stands for Communicate, Alter Command Gradient, Situational Awareness and Minimise Disruption. Many guides, instructors and leaders will already carry out some of the practices that these headings aim to capture. There is no intention to negate existing behaviours or propose CASM as a single option. It is a Human Factors tool that can be used alongside others, or in conjunction with decision making frameworks such as Be Avalanche Aware (BAA).

CASM v3.0 – Human Factors Tool

It is hoped that CASM can be used alongside other established technical skills to reduce the risk of lapses in non-technical skills such as “heuristic traps” which are often referred to in avalanche education. The aim is the safe conduct of a mountaineering, climbing or skiing day.

Communicate // “Say what you see”

Communication is arguably the non-technical skill from which all the other headings flow. In fact, it is an essential element of all the others listed. Communication is regarded as critical for groups to perform effectively in winter snow sports (Trempler 2008, Zweifel 2014) and in aviation (CAA 2016). The aim is to establish and maintain lines of communication between members of the group, and also between the leader and the group and vice versa. Discussion of the avalanche (or other) hazard is useful, along with the mantra of “saying what you see”. 

We should:

  • Share information actively
  • Clearly state our plans
  • Express uncertainty or ambiguity
  • Assure understanding

A leader using a logical structure to communicate demonstrates the legitimacy of authority due to competence. i.e. you have thought about your work and presented it in a rational and organised manner. The use appropriate language is useful to establish credibility and trust (Ginnet 2019).

Example: Clothing and the elements in which we work can make communication difficult. Ensure that people are ready to receive information and that you can be seen and heard. It is also essential to make sure that information has been received and understood by humble enquiry and observation.

Alter Command Gradient // “Disavow perfection”

The aim is to flatten any hierarchy between the leader and the group. Although leaders will have established legitimate authority having been engaged to carry out their role, there will be times when it is appropriate to carry out tasks as a group. A leader is building a relationship by saying that although they have overall responsibility for the enterprise, members of the group can take on some of that responsibility as well. This is particularly important to create a situation where the leader is not relied upon entirely without question, especially if they make an error.

We have probably all felt unable to express an opinion, or share our observations in some groups to a guide, instructor or leader who is perceived as more senior. It is easy to think our observation might already be known, or dismissed as unimportant. A worse situation would be if our views have been met with a negative or uncivil response in the past.

Example: The aim is to avoid these situations and a frequent briefing for off piste skiing in avalanche terrain is a good place to start: “Any avalanche or snow observations that you think might be useful, I would really appreciate having my attention drawn to it. I will be keeping my eye out as well, but there is always the potential for me to miss things”.

This simple statement is an example of disavowing perfection, by sharing a personal shortcoming e.g. everybody can be looking in the wrong direction, you demonstrate that you are not only human but can deal with you own vulnerabilities (Ginnet 2019, McKenna 2019).

Nobody feels comfortable in a group where the leader is always right. With a flatter hierarchy you empower people to speak up if they are uncomfortable or concerned.

Situational Awareness // “Anticipate what may happen next”

Situational Awareness is a broad concept which simply means having an idea of what is going on, but also being able to project into the future and anticipate what may happen next. A common term in aviation; it is a broad catch all. 

Watch for the cues of loss of Situational Awareness (CAA 2016): Ambiguity, fixation, confusion, not prioritising the task, “being head down”, and being unable to resolve discrepancies. Effective communication between members of the groups can reduce confusion, ambiguity and avoid being focussed on one task. 

Manage the factors which reduce awareness (Zacharias 2019) such as wellness, fatigue and distraction.

Example: In the mountains we can strive to achieve a shared mental model for the day and anticipate what may lie over the horizon. Start by having plans a, b and c along with contingencies. 

Minimise Distraction // “Sterile cockpit”

Focus on tasks that enhance safety. The perception of danger requires focus and attention. Chatting, texting and checking social media at the wrong time can detract from the environment and decision making.

The term “sterile cockpit” is used to describe any period of time when crews or groups should not be disturbed except for matters critical to the safety. Additionally, leaders should focus on their essential operational activities (Pollitt 2021).

As such you might plan to call for a sterile cockpit at certain points in the day, or alternatively foster all group members to request it if they are stretched or distracted (Hearns 2019).

Example: At key places during your day you may request not to be disturbed by anybody while decision making, and it is a two-way street, don’t disturb others. Conversation should be purposeful and relevant. It is ok to ask for silence to concentrate on navigation, technical tasks or making observations.

CASM v3.0 Video

CASM v3.0 Infographic

CASM v 3.0 infographic



Be Avalanche Aware, Snow and Avalanche Foundation for Scotland / Scottish Avalanche Information Service.

Jackson D, 2021, [Personal communication], Mountain CRM, Case Study: Take-Off with contamination on the wings prevented by cabin crew.

Jarvis (Ed), 2016, CAP737: Flight crew human factors handbook, Civil Aviation Authority

Ginnet 2019, Crews as Groups: Their Formation and Leadership. Crew Resource Management, Elsevier Inc.

Hearns S, 2019, Peak Performance Under Pressure: Lessons from a Helicopter Rescue Doctor. Class Professional Publishing.

McKenna L, 2019, [Personal communication] Mountain Manners, Not Mountain Madness. Proceedings of the Snow and Avalanche Foundation for Scotland conference, Inverness.

Pollit A, 2021,

Statham G, 2021, Thinking in Risk: Avalanche Education, Powder Cloud.

Trempler B, 2008, Staying alive in avalanche terrain. 2 edition, Seattle, WA: The Mountaineers

Zacharias C, 2019, The Power of Noticing: Avalanche Education, Powder Cloud.

Zweifel 2014, SOCIAL – A group check tool. Proceedings of the International Snow Science Workshop, Banff.