LINE OPERATIONS SAFETY AUDIT (LOSA) |
(Last Revision: Dec. 10, 2010)
1.1 INTRODUCTION
1.1.1 Historically, the way the aviation
industry has investigated the impact of human performance on
aviation safety has been through the retrospective analyses
of those actions by operational personnel, which led to rare
and drastic failures. The conventional investigative
approach is for investigators to trace back an event under
consideration to a point where they discover particular
actions or decisions by operational personnel that did not
produce the intended results and, at such point, conclude
human error as the cause. The weakness in this approach is
that the conclusion is generally formulated with a focus on
the outcome, with limited consideration of the processes
that led up to it. When analyzing accidents and incidents,
investigators already know that the actions or decisions by
operational personnel were “bad” or “inappropriate”, because
the “bad” outcomes are a matter of record. In other words,
investigators examining human performance in safety
occurrences enjoy the benefit of hindsight. This is,
however, a benefit that operational personnel involved in
accidents and incidents did not have when they selected what
they thought of as “good” or “appropriate” actions or
decisions that would lead to “good” outcomes.
1.1.2 It is inherent to traditional
approaches to safety to consider that, in aviation, safety
comes first. In line with this, decision making in aviation
operations is considered to be 100 percent safety-oriented.
While highly desirable, this is hardly realistic. Human
decision making in operational contexts is a compromise
between production and safety goals. The optimum decisions
to achieve the actual production demands of the operational
task at hand may not always be fully compatible with the
optimum decisions to achieve theoretical safety demands. All
production systems, and aviation is no exception, generate a
migration of behaviors: due to the need for economy and
efficiency, people are forced to operate at the limits of
the system’s safety space. Human decision making in
operational contexts lies at the intersection of production
and safety and is therefore a compromise. In fact, it might
be argued that the trademark of experts is not years of
experience and exposure to aviation operations, but rather
how effectively they have mastered the necessary skills to
manage the compromise between production and safety.
Operational errors are not inherent in a person, although
this is what conventional safety knowledge would have the
aviation industry believe. Operational errors occur as a
result of mismanaging or incorrectly assessing task and/or
situational factors in a specific context and thus cause a
failed compromise between production and safety goals.
1.1.3. The compromise between production
and safety is a complex and delicate balance. Humans are
generally very effective in applying the right mechanisms to
successfully achieve this balance, hence the extraordinary
safety record of aviation. Humans do, however, occasionally
mismanage or incorrectly assess task and/or situational
factors and fail in balancing the compromise, thus
contributing to safety breakdowns. Successful compromises
far outnumber failed ones; therefore, in order to understand
human performance in context, the industry needs to
systematically capture the mechanisms underlying successful
compromises when operating at the limits of the system,
rather than those that failed. It is suggested that
understanding the human contribution to successes and
failures in aviation can be better achieved by monitoring
normal operations, rather than accidents and incidents. The
Line Operations Safety Audit (LOSA) is the vehicle endorsed
by ICAO to monitor normal operations.
1.1.4. The Line Operations Safety Audit
Program describes the process by which all airline flight
crewmembers are evaluated on professional standards. This
section is designed to provide instructions, guidance, and
regulatory requirements for evaluating flight crewmembers
during these observations. As professionals, airline flight
crewmembers are expected to exhibit the highest degree of
airmanship, integrity, professionalism, proficiency, and
safety. The flight crewmembers should be a master of the
airplane, and demonstrate an ability to operate under
complex circumstances throughout the range and scope of
his/her duties. Additionally, the flight crewmember bears
the final responsibility for the safe conduct of the flight.
This standard, more than any other, distinguishes the flight
crewmember as a professional. This mastery of complex
problems, good judgment, situational awareness, crew
resource management, and leadership skills is necessary to
ensure that safety is never compromised. Flight Manual Part
1, the appropriate Aircraft Operating Manual, and the Line
Operations Safety Audit Program provide the framework for
ensuring standardized flight operations. However, when
situations arise that are not specifically addressed by
these manuals or FARs, the Flight Crew is expected to
exercise professional judgment while maintaining safety of
flight as the first priority. The Line Operations Safety
Audit Program is the responsibility of the Manager of Flight
Safety. Written comments and suggestions may be submitted
via board mail to the Safety Department. All flight
operations are subject to the Line Operations Safety Audit
Program. The determination of whether a flight crewmember’s
performance is acceptable is derived from the experience and
judgment of the LOSA Observer. The LOSA Observer must
evaluate carefully, consistently, and in accordance with the
operating procedures outlined in the appropriate Aircraft
Operating Manual.
1.2 BACKGROUND
Reactive strategies/ Accident
investigation
1.2.1 The tool most often used in
aviation to document and understand human performance and
define remedial strategies is the investigation of
accidents. However, in terms of human performance, accidents
yield data that are mostly about actions and decisions that
failed to achieve the successful compromise between
production and safety discussed earlier in this chapter.
1.2.2 There are limitations to the
lessons learned from accidents that might be applied to
remedial strategies vis-a-vis human performance. For
example, it might be possible to identify generic
accident-inducing scenarios such as Controlled Flight Into
Terrain (CFIT), Rejected Takeoff (RTO), runway incursions
and approach-and-landing accidents. In addition, it might
be possible to identify the type and frequency of external
manifestations of errors in these generic accident-inducing
scenarios or discover specific training deficiencies that
are particularly related to identified errors. This,
however, provides only a tip-of-the-iceberg perspective.
Accident investigation, by definition, concentrates on
failures, and in following the rationale advocated by LOSA,
it is necessary to better understand the success stories to
see if they can be incorporated as part of remedial
strategies.
1.2.3 This is not to say that there is
no clear role for accident investigation within the safety
process. Accident investigation remains the vehicle to
uncover unanticipated failures in technology or bizarre
events, rare as they may be. Accident investigation also
provides a framework. If only normal operations were
monitored, defining unsafe behaviors would be a task without
a frame of reference. Therefore, properly focused accident
investigation can reveal how specific behaviors can combine
with specific circumstances to generate unstable and likely
catastrophic scenarios. This requires a contemporary
approach to the investigation. Should accident
investigation be restricted to the retrospective analyses
discussed earlier, its contribution in terms of human error
would be to increase existing industry databases, but its
usefulness in regard to safety would be dubious. In
addition, the information could possibly provide the
foundations for legal action and the allocation of blame and
punishment.
Combined reactive/proactive strategies
Incident investigation
1.2.4 A tool that the aviation industry
has increasingly used to obtain information on operational
human performance is incident reporting. Incidents tell a
more complete story about system safety than accidents do
because they signal weaknesses within the overall system
before the system breaks down. In addition, it is accepted
that incidents are precursors of accidents and that N-number
of incidents of one kind takes place before an accident of
the same kind eventually occurs. The basis for this can be
traced back almost 30 years to research on accidents from
different industries, and there is ample practical evidence
that supports this research. There are, nevertheless,
limitations of the value of the information on operational
human performance obtained from incident reporting.
1.2.5 First, reports of incidents are
submitted in the jargon of aviation and, therefore, capture
only the external manifestations of errors (for example,
“misunderstood a frequency”, “busted an altitude”, and
“misinterpreted a clearance”). Furthermore, incidents are
reported by the individuals involved, and because of biases,
the reported processes or mechanisms underlying errors may
or may not reflect reality, this means that
incident-reporting systems take human error at face value,
and, therefore, analysts are left with two tasks. First,
they must examine the reported processes or mechanisms
leading up to the errors and establish whether such
processes or mechanisms did indeed underlie the manifested
errors. Then, based on this relatively weak basis, they must
evaluate whether the error management techniques reportedly
used by operational personnel did indeed prevent the
escalation of errors into a system breakdown.
1.2.6 Second, and most important,
incident reporting is vulnerable to what has been called
“normalization of deviance”. Over time, operational
personnel develop informal and spontaneous group practices
and shortcuts to circumvent deficiencies in equipment
design, clumsy procedures or policies that are incompatible
with the realities of daily operations, all of which
complicate operational tasks. These informal practices are
the product of the collective expertise and hands-on
expertise of a group, and they eventually become normal
practices. This does not, however, negate the fact that they
are deviations from procedures that are established and
sanctioned by the organization, hence the term
“normalization of deviance”. In most cases, normalized
deviance is effective, at least temporarily. However, it
runs counter to the practices upon which system operation is
predicated. In this sense, like any shortcut to standard
procedures, normalized deviance carries the potential for
unanticipated “downsides” that might unexpectedly trigger
unsafe situations. However, since they are "normal”, it
stands to reason that neither these practices nor their
downsides will be recorded in incident reports.
1.2.7 Normalized deviance is further
compounded by the fact that even the most willing reporters
may not be able to fully appreciate what are indeed
reportable events. If operational personnel are continuously
exposed to substandard managerial practices, poor working
conditions, and or flawed equipment, how could they
recognize such factors as reportable problems?
1.2.8 Thus, incident reporting cannot
completely reveal the human contribution to successes or
failures in aviation and how remedial strategies can be
improved to enhance human performance. Incident reporting
systems are certainly better than accident investigations in
understanding system performance, but the real challenge
lies in taking the next step understanding the processes
underlying human error rather than taking errors at face
value. It is essential to move beyond the visible
manifestations of error when designing remedial strategies.
If the any airline is to be successful in modifying system
and individual performance, errors must be considered as
symptoms that suggest where to look further. In order to
understand the mechanisms underlying errors in operational
environments, flaws in system performance captured through
incident reporting should be considered as symptoms of
mismatches at deeper layers of the system. These mismatches
might be deficiencies in training systems, flawed person
technology interfaces, poorly designed procedures, corporate
pressures, poor safety culture, etc. The value of the data
generated by incident reporting systems lies in the early
warning about areas of concern, but such data do not capture
the concerns themselves.
Training
1.2.9 The observation of training
behaviors (during flightcrew simulator training, for
example) is another tool that is highly valued by the
aviation industry to understand operational human
performance. However, the “production” component of
operational decision making does not exist under training
conditions. While operational behaviors during line
operations are a compromise between production and safety
objectives, training behaviors are absolutely biased towards
safety. In simpler terms, the compromise between production
and safety is not a factor in decision making during
training. Training behaviors are “by the book”.
1.2.10 Therefore, behaviors under
monitored conditions, such as during training or line
checks, may provide an approximation to the way operational
personnel behave when unmonitored. These observations may
contribute to flesh out major operational questions such as
significant procedural problems. However, it would be
incorrect and perhaps risky to assume that observing
personnel during training would provide the key to
understanding human error and decision making in unmonitored
operational contexts.
Surveys
1.2.11 Surveys completed by operational
personnel can also provide important diagnostic information
about daily operations and, therefore, human error. Surveys
provide an inexpensive mechanism to obtain significant
information regarding many aspects of the organization,
including the perceptions and opinions of operational
personnel: the relevance of training to line operations, the
level of teamwork and cooperation among various employee
groups, problem areas or bottlenecks in daily operations,
and eventual areas of dissatisfaction. Surveys can also
probe the safety culture. For example, do personnel know the
proper channels for reporting safety concerns and are they
confident that the organization will act on expressed
concerns? Finally, surveys can identify areas of dissent or
confusion, for example, diversity in beliefs among
particular groups from the same organization regarding the
appropriate use of procedures or tools. On the minus side,
surveys largely reflect perceptions. Surveys can be likened
to incident reporting and are therefore subject to the
shortcomings inherent to reporting systems in terms of
understanding operational human performance and error.
Flight data recording
1.2.12 Digital Flight Data Recorder (DFDR)
and Quick Access Recorder (QAR) information from normal
flights is also a valuable diagnostic tool. There are,
however, some limitations about the data acquired through
these systems. DFDR/QAR readouts provide information on the
frequency of exceedences and the locations where they occur,
but the readouts do not provide information on the human
behaviors that were precursors of the events. While DFDR/QAR
data track potential systemic problems, pilot reports are
still necessary to provide the context within which the
problems can be fully diagnosed.
1.2.13 Nevertheless, DFDR/QAR data hold
high cost/efficiency ratio potential. Although probably
underutilized because of cost considerations as well as
cultural and legal reasons, DFDR/QAR data can assist in
identifying operational contexts within which migration of
behaviors towards the limits of the system takes place.
Proactive strategies
Normal line operations monitoring
1.2.14 The approach proposed in this
manual to identify the successful human performance
mechanisms that contribute to aviation safety and,
therefore, to the design of countermeasures against human
error focuses on the monitoring of normal line operations.
1.2.15 Any typical routine flight - a
normal process - involves inevitable, yet mostly
inconsequential errors (selecting wrong frequencies, dialing
wrong altitudes, acknowledging incorrect read-backs,
mishandling switches and levers, etc.) Some errors are due
to flaws in human performance while others are fostered by
systemic shortcomings; most are a combination of both. The
majority of these errors have no negative consequences
because operational personnel employ successful coping
strategies and system defenses act as containment nets. In
order to design remedial strategies, the aviation industry
must learn about these successful strategies and defenses,
rather than continue to focus on failures, as it has
historically done.
1.2.16 A medical analogy may be
helpful in illustrating the rationale behind LOSA. Human
error could be compared to a fever: an indication of an
illness but not its cause. It marks the beginning rather
than the end of the diagnostic process. Periodic monitoring
of routine flights is therefore like periodic physical:
proactively checking health status in an attempt to avoid
getting sick. Periodic monitoring of routine flights
indirectly involves measurement of all aspects of the
system, allowing identification of areas of strength and
areas of potential risk. On the other hand, incident
investigation is like going to the doctor to fix symptoms of
problems; possibly serious, possibly not. For example, a
broken bone sends a person to the doctor; the doctor sets
the bone but may not consider the root cause(s): weak bones,
poor diet, high-risk lifestyle, etc. Therefore, setting the
bone is no guarantee that the person will not turn up again
the following month with another symptom of the same root
cause. Lastly, accident investigation is like a postmortem:
the examination made after death to determine its cause. The
autopsy reveals the nature of a particular pathology but
does not provide an indication of the prevalence of the
precipitating circumstances. Unfortunately, many accident
investigations also look for a primary cause, most often
“pilot error”, and fail to examine organizational and system
factors that set the stage for the breakdown. Accident
investigations are autopsies of the system, conducted after
the point of no return of the system’s health has been
passed.
1.2.17 There is emerging consensus
within the aviation industry about the need to adopt a
positive stance and anticipate, rather than regret, the
negative consequences of human error in system safety. This
is a sensible objective. The way to achieve it is by
pursuing innovative approaches rather than updating or
optimizing methods from the past. After more than 50 years
of investigating failures and monitoring accident
statistics, the relentless prevalence of human error in
aviation safety would seem to indicate a somewhat misplaced
emphasis in regard to safety, human performance and human
error; unless it is believed that the human condition is
beyond hope.
1.3 A CONTEMPORARY APPROACH TO
OPERATIONAL HUMAN PERFORMANCE
AND ERROR
1.3.1. The implementation of normal
operations monitoring requires an adjustment on prevailing
views of human error. In the past, safety analyses in
aviation have viewed human error as an undesirable and
wrongful manifestation of human behavior. More recently, a
considerable amount of operationally oriented research,
based on cognitive psychology, has provided a very different
perspective on operational errors. This research has proven,
in practical terms, a fundamental concept of cognitive
psychology: error is a normal component of human behavior.
Regardless of the quantity and quality of regulations the
industry might promulgate, the technology it might design,
or the training people might receive, error will continue to
be a factor in operational environments because it simply is
the downside of human cognition. Error is the inevitable
downside of human intelligence; it is the price human beings
pay for being able to “think on our feet”. Practically
speaking, making errors is a conservation mechanism
afforded by human cognition to allow humans the flexibility
to operate under demanding conditions for prolonged periods
without draining their mental “batteries”.
1.3.2. There is nothing inherently wrong
or troublesome with error itself as a manifestation of human
behavior. The trouble with error in aviation is the fact
that negative consequences may be generated in operational
contexts. This is a fundamental point in aviation: if the
negative consequences of an error are caught before they
produce damage, then the error is inconsequential. In
operational contexts, errors that are caught in time do not
produce negative consequences and therefore, for practical
purposes, do not exist. Countermeasures to error, including
training interventions, should not be restricted to avoiding
errors, but rather to making them visible and trapping those
before they produce negative consequences. This is the
essence of error management: human error is unavoidable but
manageable.
1.3.3. Error management is at the heart
of LOSA and reflects the previous argument. Under LOSA,
flaws in human performance and the ubiquity of error are
taken for granted and, rather than attempting to improve
human performance, the objective becomes to improve the
context within which humans perform. LOSA ultimately aims
through changes in design, certification, training,
procedures, management and investigation – at defining
operational contexts, including buffer zones or time delays
between the commission of errors and the point in which
error consequences become a threat to safety. The buffer
zone or time delay allows for recovery from the consequences
of errors. The more resistant the buffer or the longer the
time delay, the stronger the intrinsic resistance and
tolerance of the operational context to the negative
consequences of human error. Operational contexts should be
designed in such a way that allows front-line operators
second chances to recover from the consequences of errors.
1.3.4. In making an analogy with flight
instruments, human performance can be considered as falling
into three bands: a “green” band”, a “yellow band”, and a
“red band”. Within the “green band”, the operational
context demands are low. Task and situational factors are
compatible with cognitive resources, operational personnel
make the fewest errors and, as indicated by the high
recovery rate, the operational personnel have ample
cognitive resources in reserve to recover from the negative
consequences of errors. Task and situational factors put
human performance into the “yellow band” when the
operational context demands increase and become more complex
and, consequently, errors increase in number and the
recovery rate decreases. As operational context demands
continue to increase and eventually peak, task and
situational factors force human performance into the “red
band”. In this band, the number of errors sharply jumps and
the recovery rate dips to a point at which cognitive control
is lost. At this point, cognitive resources are no longer
available to cope with the situation at hand; the mental
“batteries” are totally depleted.
1.3.5. This classification of human
performance into bands is beneficial to organizations to
apply the LOSA data. As an example, the term “coffin
corner” is used to describe the point in the operational
envelope of an aircraft at which the (low) stall speed and
the (high) buffet speed are the same and the aircraft
exhibits bizarre behavior and eventually goes out of
control. Weight-verses-altitude-and-speed capability charts
and other tools provide flightcrews with the necessary
information to avoid operating aircraft in this condition
and, therefore, to stay within a safe operating envelope.
LOSA generates the information necessary for organizations
to define the “green band” of safe operations in the human
performance envelope, thus avoiding taking operational human
performance into the “coffin corner” of cognition.
1.4 THE ROLE OF THE
ORGANIZATIONAL CULTURE
1.4.1. In order to understand how an
organization can effectively implement approaches to error
management, it is essential to examine the organization’s
daily processes, the kind of corporate culture such
processes generate, and the organization’s attitudes toward
error and punishment. This will make it possible to assess
the effectiveness of the controls that the organization has
in place to ensure that its processes foster the “green
band” of operational human performance. It is good to
remember the following points: humans do not live in a
vacuum so their behaviors are affected by many external
factors; corporate culture is an organizational mandate that
conditions operational personnel decision making; and humans
exhibit the kinds of behaviors an organization fosters and
which they therefore assume the organization expects of
them.
1.4.2. In closing this section, it is
important to clearly point out the distinction between
errors – which are products of human limitations, and
violations – which have a motivational component. While
errors should be considered as the inevitable downside of
human intelligence and flexibility and the aviation industry
must learn to live with it, violations should be considered
from a different perspective. Violations are an emerging
topic of research, and in due time, the aviation industry
might need to change prevailing attitudes towards them.
However, for the purposes of this manual, violations should
not be condoned.
1.5 CONCLUSION
1.5.1. There is no denying that
monitoring normal operations on a routine basis poses major
challenges. Significant progress has been achieved in
tackling some of these challenges. From a methodological
point of view, some of the early problems in defining,
classifying and standardizing the data obtained have been
solved with this program revision. From an organizational
perspective, there is a need to consider using multiple data
collection tools, including line observations, surveys,
self-reports such as ASAP Reports, and more refined safety
incident reporting and Flight Data Analysis systems such as
FOQA. Each tool can provide its own unique part of the
whole picture and, taken as a whole, provide any airline
with a comprehensive look at their actual operations.
For more information on how your company can
quickly gain these advantages, please
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