Success of CRM
In the 1970s, investigators discovered that more than 70% of air crashes involved human error rather than failures of
equipment or weather. A NASA workshop examining the role of human error in air crashes found that the majority of crew
errors consisted of failures in leadership, team coordination, and decision-making.
The aviation community responded by turning to psychologists such as John K. Lauber, PhD, and Robert Helmreich, PhD, to
develop new kinds of psychological training for flight crews. That training focuses on group dynamics, leadership,
interpersonal communications, and decision-making. The training is known as crew resource management (CRM). Lauber, a
former member of the National Transportation Safety Board, defined CRM as “using all available sources—information,
equipment, and people—to achieve safe and efficient flight operations.” More specifically, CRM is the process used by crew
members to identify existing and potential threats and to develop, communicate, and implement plans and actions to avoid
or mitigate perceived threats. Using CRM methods, airplane crews can avoid, manage, and mitigate human errors. And as
secondary benefits, CRM programs improve morale and enhance efficiency of operations.
As part of the validation of the behavioral impact of CRM training, Helmreich (who is now deceased) and colleagues at the
University of Texas Human Factors Research Project developed an observational process, the Line Operations Safety Audit
(LOSA) to assess CRM practices. In LOSA, expert observers ride in the cockpit on scheduled flights under conditions of strict
confidentiality and record not only CRM practices but also threats in the operational environment and how they are
managed, as well as the nature and management of crew errors. LOSA data have provided valuable information about the
threats that air crew members face, and how CRM practices help them deal with those threats.
Significance
CRM alerted the aviation industry to the human interactions that are an integral part of any team performance. This
training has the potential to save lives and money, as well as prevent accidents and lawsuits.
While no one can assess how many lives have been saved or crashes averted as a result of CRM training, the impact has
been significant. LOSA data demonstrate that 98% of all flights face one or more threats, with an average of four threats
per flight. Errors have also been observed on 82% of all flights with an average of 2.8 per flight. Consistent with the
outstanding safety record of commercial aviation, the great majority of errors are well managed and inconsequential, due
in large measure to effective CRM practices by crews. LOSA provides organizations and regulators with a valid means of
monitoring normal operations. By understanding what crews do successfully as well as where things go wrong, researchers
can help develop more effective training and safety initiatives.
A real-world example of how CRM may have saved lives can be found in the textbook Social Psychology, by psychologist
David Myers, PhD, comparing two airline crashes in the 1980s:
Helmreich (1997)…notes that flawed group dynamics were evident when an Air Florida plane lifted off from Washington’s
National Airport (now Reagan National Airport) on a winter day in 1982. Ice in a sensor caused the speed indicators to read
too high, leading the captain to apply too little power as the plane ascended:
First Officer: Ah, that’s not right.
Captain: Yes, it is, there’s 80 [referring to speed].
First Officer: Nah, I don’t think it’s right. Ah, maybe it is.
Captain: Hundred and twenty.
First Officer: I don’t know.
It wasn’t right, and the first officer’s muting his concerns led to the plane’s stalling and crashing into a Potomac River
bridge, killing all but five people on board.
But in 1989, the three-person crew flying a United Airlines DC-10 flight from Denver to Chicago responded as a model team
to imminent disaster. The crew, whose members had been trained in crew resource management, faced the disintegration
of the center engine, severing lines to the rudder and ailerons needed to maneuver the plane. In the 34 minutes before
crash landing just short of the Sioux City airport runway, the crew had to devise a strategy for bringing the plane under
control, assessing damage, choosing a landing site, and preparing the crew and passengers for the crash. Minute-by-minute
analysis of the cockpit conversation revealed intense interaction—31 communications per minute (one per second at its
peak). In these minutes, the crew members recruited a fourth pilot who was flying as a passenger, prioritized their work,
and kept one another aware of unfolding events and decisions. Junior crew members freely suggested alternatives and the
captain responded with appropriate commands. Bursts of social conversation provided emotional support, enabling the
crew to cope with the extreme stress, and to save the lives of 185 of the 296 people on board.
Practical application
Based on the evidence that CRM is effective, the International Civil Aviation Organization, a regulatory component of the
United Nations, began requiring CRM programs for member countries. CRM also informed the development of
maintenance resource management, an effort to improve teamwork among aircraft maintenance workers. The U.S. Air
Force, among others, now uses CRM training programs to boost communication, effectiveness, and safety among the crews
that maintain and repair aircraft.
CRM training is also being used in air traffic control, firefighting, and industrial settings, including offshore oil operations
and nuclear power plants. The training helps workers in control rooms and emergency command centers avoid making
operational errors that may lead to accidents.
I remember a comment my instructor made during flight school for ultralights: “Are you ahead of the aircraft or behind it?”
Obviously, the key is to be ahead of the aircraft, where you are in control and anticipating what will happen next. Once the
situation turns around and you are behind the plane and reacting, you’re in trouble.
Many aviation incidents are the result of an inappropriate response to unexpected events. These are often loss of control
(LOC) incidents, where there is an unintended departure of the aircraft from controlled flight. For example, the aircraft
departs from its normal flight envelope and stalls. The pilot is unable to regain control of the aircraft. The pilot is not ahead
of the plane but instead is behind, reacting to its movements rather than anticipating them.
We also can have LOC incidents during arboricultural operations. You are either in control of the tree or it is in control of
you. The dismantling job starts out just fine, everything seems to be going as planned, but then the climber notices a conk
(fruiting body to a fungus) on the limb holding the block and expresses a concern that the limb might not support the
rigging load. The comment is ignored by a distracted crew leader dealing with the customer, so the climber shrugs and
starts the saw. The crew should have noticed the conk during the pre-work inspection, but the inspection wasn’t done till
the climber was already in the tree.
The new crew member tending the lowering device is standing beneath the tree holding the line, not knowing what to do
because no one explained how to lower a limb or operate the device. The crew member who is supposed to be responsible
for the operation is busy replacing a chain that another worker had dug into the dirt while cutting up some logs. This crew
member figures he has time, since the climber is supposed to be setting up the rigging rather than starting to cut so soon.
The climber neglects to communicate that he is cutting the limb now – since it makes him nervous and he wants to get it
over with. The only warning the new worker has is that the line to the lowering device suddenly goes taut. The limb cracks
under the load and swings toward the climber as the startled ground crew runs to escape the falling debris. Now everyone
is reacting to the tree – not leading it.
Undetected errors can lead to critical failures that become incidents. What leads to these incidents? Usually one or more of
these factors:
Interruptions and distractions – The crew leader is talking to the customer, and a crew member is having to replace a chain.
Tasks taken out of sequence – The job briefing was delayed until the climber was already aloft, and no one considered
aerial hazards, instead focusing on hazards they deal with on the ground.
Unanticipated tasks – The new ground member did not know the limb was being cut when it was, and the crew leader had
not expected to be talking to the customer.
Interweaving of multiple tasks – A common theme to many incidents is information overload; a discussion with the
customer, replacing a nicked chain and cutting a limb all were occurring simultaneously rather than everyone focusing on
the one critical task – safely lowering the limb.
A contributing factor in this scenario was communication failure; all people involved were in their own little bubble, which
is a challenge that aviation had to address. If you are the pilot and only passenger, it’s all on you. However, if you are
sharing responsibilities, it’s essential that both the captain and first officer each clearly understands their duties and
responsibilities. The challenge in aviation was that the captain was the authority; the captain’s commands were not to be
questioned, but followed.
This rigid hierarchy was considered a factor in many aviation incidents. Communication failure was the primary contributing
factor in more than three-quarters of the root-cause analysis of aviation incidents. Incidents occurred when the co-pilot or
flight engineer was aware of an error but was unwilling or unable to alert the captain. One incident involved the captain
focusing on a landing-gear problem for an hour and ignoring the flight engineer’s warning that their fuel was critically low.
The plane ran out of fuel on its final approach and crashed short of the runway, killing 10 passengers aboard.
Crew resource management (CRM) was the outcome of the analysis of these incidents. The idea was to create a less-
restrictive environment where first officers could question captains if they observed conditions that might lead to errors.
The captain was still the captain and the hierarchy of command was maintained, but respectfully questioning authority was
permissible and desirable.
Situational awareness involves being constantly aware of the surroundings and alert to any unanticipated changes.
Everyone on the team must maintain an awareness of the entire operation as it unfolds, not just their present task,
recognizing when conditions change beyond planning and determining whether these changes require corrective action.
This requires communication among the team members.
The objectives of CRM are to overcome communication issues, improve decision-making and define leadership
responsibilities among others. The goal is to empower the team members to use all their skills and knowledge to effectively
and safely perform their duties. This approach went beyond just the captain and first officer to include all flight personnel.
It now has expanded to other professions where human errors can have fatal outcomes, such as emergency medical
services.
Arboriculture shares few similarities to aviation other than they both are high risk (pilots and flight crews have a higher
fatality rate than arborists). But we also are guilty of having a rigid hierarchy – one crew leader and everyone else is the
crew. Too often the crew leader’s instructions are followed despite misgivings by the crew.
We had one incident when a crew member was told by the crew leader to fell a tree into an adjacent dead tree so both
would fall, a risky procedure and one that should not be attempted. However, the crew leader was the boss, so the crew
member cut the live tree to fall into the other tree. As the saw operator stepped back along his retreat path, he was fatally
struck by a dead limb that snapped off the dead tree on impact with the felled tree.
In another instance, the crew leader stepped up on the in-feed table to clear a jam in the chipper. He told his crew to stand
back, they weren’t supposed to do this, but he would jump up there and kick the jam free. Instead, his foot caught and he
was pulled completely through the chipper. Obviously, standing on the in-feed table is a violation of safety regulations and
common sense, but the crew just stood by and watched.
Operating in any high-risk environment requires a highly functional team, as the cost of errors is high. Tree care companies
would be wise to consider the CRM approach to team management.
Five key components to CRM
1. Mission planning
The first step – plan the work and ensure all members of the team know their roles and responsibilities. This is part of the
all-important (and frequently ignored) prework inspection and job briefing required for arboricultural operations. These are
the keys to a safe and efficient operation, and these are common among many other occupations where the outcome of
errors can be fatal.
During the ultralight flight school (all of 15 hours with another 15 of dual flight), they taught us that the importance of a
thorough pre-flight cannot be overemphasized. The pre-flight procedure is performed systematically, never varied, and
done with the co-pilot (unless flying solo).
According to the ANSI Z133 Safety Requirements for Arboricultural Operations, section 3.4.3, a job briefing shall be
performed by the qualified arborist in charge before the start of each job. While the crew leader is responsible for the
briefing, that does not mean it has to be read as a litany. That’s a good way for crew members to become bored and
distracted. Instead, the crew leader can call on crew members to lead it or to lead one of the subjects required to be
covered in the job briefing: hazards associated with the job, electrical hazards, personal protective equipment, job
assignments and work procedures. After all, arboriculture is a team effort and everyone, not just the leader, should know
the job, not just their tasks. If you know the work procedure, you are more likely to be aware when the situation changes.
2. Maximizing situational awareness
Situational awareness involves being constantly aware of the surroundings and alert to any unanticipated changes.
Everyone on the team must maintain an awareness of the entire operation as it unfolds, not just their present task,
recognizing when conditions change beyond planning and determining whether these changes require corrective action.
But this requires communication among the team members.
3. Clear communication
Clear communication goes beyond having a communication protocol, for example, our command-and-response system.
Every team member must be empowered to communicate any concerns at any point during the operation as well as voice
corrections or clarifications. While there must be a defined leader, all voices should be equal, and everyone has the
responsibility to identify potential errors and come up with solutions.
When workers are told to shut up and go back to work, rather than allowed to voice a concern, the team is in trouble. The
last comment you want to hear from someone is, “That’s not my job.” Safety is everyone’s job, and it starts with teamwork.
In the Swiss-cheese model of process safety, incidents occur only when the errors (holes in the Swiss cheese) line up
through the multiple layers of cheese. Illustration by David Mack.
4. Improved teamwork
Teamwork begins with training on the protocols and operating procedures. Everyone must learn to interact. A key is the
understanding that all humans, which is everyone on the team, including the leader, make mistakes. In the Swiss-cheese
model of process safety (figure at left), incidents occur only when the errors (holes in the Swiss cheese) line up through the
multiple layers of cheese. A means of reducing failures due to human error is to insert additional layers of cheese – every
crew member who is working as part of the team becomes a layer. It does not matter if you are the climber or a ground
pounder, you are equally important in detecting errors.
5. Effective decision-making
Team members continually evaluate the situation, staying focused on what is occurring and anticipating possible
corrections and consequences. This is really the culmination of the previous four points.
“To err is human” goes part of the phrase by Alexander Pope. Humans, even crew leaders, make errors. But we want errors
not to evolve into failures and incidents. The key purpose of CRM is management of human errors, and that is best
accomplished as a team working together to efficiently and safely perform the job. Remember, you are as safe as your
least-trained worker; everyone has an equal responsibility for the safety of the team.
