Failure To Comply
When the airplane crashed the probable cause was determined to be flight crew’s preoccupation with matters unrelated to cockpit duties. About sixty years later the probable cause in an airplane crash was the pilot’s failure to maintain airspeed and correct pitch attitude. Over a period of 60 year the probable cause was turned upside down, or 180 degrees and had gone from tasks performed to tasks that was not performed. In the 50’s they got the correct probable cause, while today the cause is assigned to an event that didn’t take place. The difference is that it is impossible to fail to comply with a task since one task or another is always performed. In addition, it becomes impossible to develop corrective action plans to a task that did not occur.
Airplane crashes happens because of human behavior and not because of human error, or failure to comply with an arbitrary defined task. There is a reason for the Safety Management System to consider human factors, organizational factors, supervision factors and environmental factors in a root cause analysis. There is a reason for airports to train their airside personnel in human and organizational factors prior to being assigned airside tasks. There is a reason that some airports apply crew resources management training to airside personnel just as an airline apply these principles to their flight crew. The reason is that it is human nature is to take the path of least resistance, which includes preoccupation with trivial tasks.
The Safety Management System is a wonderful process control tool applied to operations. When processes are applied to a certificate it is operational control. When applied to job performance it is monitoring and oversight. A flight crew certificate is managed by operational control, while airport personnel are managed by performance oversight. There is an option for operational control of an airport certificate by implementing the airport zoning regulations.
It is impossible to run an effective Safety Management System without a Statistical Process Control analysis. Without process control any corrective action plans are short-term and the issue will repeat itself over and over again. A downward trend in a bar-chart or a pie-chart is not a guarantee of an in-control process. These are trending charts displaying an upward or downward trend, or the size of each piece in the pie-chart. Definition of these trends are a “good trend” or a “bad trend”, which are emotional definitions and not derived from data. Trends are not good or bad, they are just trends. Simplified, an upward trend of incidents may be “bad trend”, while it could also be a “good trend” if compared to a baseline. If an airline quadrupled their fleet and cycles, while the incidents doubled, it is a “good trend”. The question is not if operations is in a “good” or “bad” state, but if processes are operational acceptable. Either as an airport or airline, an SPC analysis control chart paints you a quality assurance pictures of your operational processes. The question then becomes how to make incremental improvements to lower the upper control limit.
Airlines are promoting themselves as the safest mode of transportation. If this is the case, why does the Global Aviation Industry, being Airlines or Airports, need a Safety Management System (SMS) today, when they were safe yesterday without an SMS? Air travel per flight may have become a safer mode of transportation today than decades ago, but the question to ask is if their operational processes are in-control with a lower upper control limit today than they were decades ago.
SMS processes are analyzed with respect to human factors, organizational factors, supervision factors and environmental factors. A root cause analysis places a weight-factor on all of these factors and the highest factor is the root cause. When investigating an accident for a probable cause one of these factors will stand out as the root cause.
In the examples below an aircraft type was randomly selected for SPC analysis of accidents between 1985 and 2019. This analysis included all global reported accidents and operators. The next step was to select one operator and analyse the processes for that specific operator. The result shows that airline travel processes are not safer today than what it was in 1985.
The first control chart shows operational control that is out-of-control. The upper control limit is 19.5, or that operators of this type of aircraft accepts a process with 19.5 accidents per year.
The control chart below of one selected operator shows an in-control-process. This operator accepts a process with 4.3 accidents per year.
Let’s assume for a moment that aviation safety has improved over the years and that the time frame between 1985 and 2019 is a bit far expanded. The next step is to analyze the same scenarios, but between 2010 and 2019.
The below control chart shows that operational processes have become less safe than in prior years.
When narrowing the time frame to 10 years, the processes produced a result with 22.7 acceptable accidents per year.
In addition, since this is an in-control-process, as opposed to an out-of-control process between 1985-2019, this process systematically accepts 22.7 accident per year.
For the operator, their operational processes produced an improved result, with acceptable processes of 3.4 accidents per year, which is down from 4.3.
When analyzing quality assurance of processes, this specific scenario produced a result that aviation processes are not safer today than what they were in 1985. That aviation is the safest mode of transportation could be an illusion. The beauty of a Safety Management System is that it will capture processes that are out-of-control and in-control processes accepting an unacceptable level of accidents. With an SPC process analysis incremental improvements can be made to human factors, organizational factors, supervision factors and environmental factors. It appears that the aviation industry in the 50’s, identifying flight crew’s preoccupation with matters unrelated to cockpit duties as a probable cause had a better grip on safety processes than they do today.