Saturday, December 1, 2012
Recently an aircraft from a major airline experienced runway excursion. Failing to negotiate the turn onto a taxiway during a snowstorm the aircraft left the pavement and came to rest in the adjacent soft ground. There were no injuries and only minor damage to the aircraft. This is the latest in a series of runway excursions for this airline. I can recall four since 2000, KBUR March 2000, KMDW December 2005, KMDW April 2011 and the most recent KDEN November 2012.
My focus of these runway excursions is not intended to be on one the airline, but to point out that all of them took place in the same type aircraft from the same operator. What was significant with these flights and shat can we learn?
The excursions listed above are anecdotally significant for three reasons. First of all, the aircraft were from the same operator (i.e. same procedures?). I will comment more about procedures later. Second, they were the same aircraft type, Boeing 737. Third, the excursions occurred with the same conditions that other aircraft encountered and landed successfully.
The latest issue of Flight Safety Foundation’s AeroSafety World has an excellent article explaining a Boeing analysis of 29 runway end excursions. Click HERE for the article. The analysis divided the incidents into three categories, landed long, landed fast and deficient deceleration. “Only three primary factors….govern the stopping of any airplane”, said A. Thomas Stephens, Lead, aero accident/incident analysis, The Boeing Co. The study looked at touchdown point, touchdown speed and deceleration capability. The study also pointed out that all flights were “capable” of making a full stop with the conditions present when they landed.
What were the differences? What were the characteristics of the operations that resulted in these runway excursions? More importantly, what were the significant factor(s) about the flights that did not have an excursion?
I submit that there is a fourth factor, as important as the laws of physics, that can exploit or negate safety margins built into procedures and performance data. That factor is crew effectiveness. By crew effectiveness I mean decision-making capability and the ability to operate the aircraft in a manner that is consistent with the manufacturer’s performance data. The aircraft in the Boeing study were capable and the crews were trained. But, trained for what objective? Is the ultimate goal to robotically follow procedure or to operate safely?
Threat and Error Management (TEM) principles have been available to operators for approaching two decades. Its concepts have been in use by effective pilots since the Wright Brothers. Some airlines have chosen to embrace it from a foundational perspective while others as an afterthought. For a few operators and their pilots it is the essence of what they do. They approach every situation with the mindset of threat identification and mitigation. Unfortunately, for many others they see Threat and Error Management as a set of platitudes and graphics that look good in presentations and sound good in training syllabi. It is the same difference that exists between those who see volunteerism as helping your friends and neighbors and those who use volunteerism to enhance their image and to feel better about themselves.
Applying very simple threat analysis and simple mitigation strategies may have prevented all 29 runway excursions in the Boeing study. Acknowledging threats and developing effective strategies before attempting to land is essential for a safe operation. The crews involved did not either acknowledge the threats or employ mitigation strategies.
Were the procedures in place at the time of the runway excursions ineffective? Or, can we simply assume the crews were intentionally non compliant? Were the crews adequately trained to operate safely (the outcome of the maneuver not in doubt) in the environment they were faced with? The only true measure of a flight crew’s training is their performance on the line. I submit that the crews were not trying to be unsafe, but rather were not effectively trained to identify and avoid or mitigate the threats. I believe the Boeing study along with runway excursion statistics in general point to a need for more effective training in this area.
Crews and operators that embrace Threat and Error Management principles see procedural compliance as a threat mitigation tool to maintain safe operations. Those who think of TEM as an add-on tend to make procedural compliance the primary goal and believe safe operations will therefore follow. Training in judgment and decision-making requires a comprehensive approach over a long period of time. It is far easier and more efficient to write and publish a procedure than to train decision-making skills. However, the more operators try to proceduralize safe operations the more crews tend to emphasize procedure over outcome. The decision-making process can become “Can we do this?” rather than “Should we do this?”. For example, effective training would produce crews that are trained to acknowledge and effectively mitigate the threats associated with landing downwind on a short runway with decreased braking action, not just trained to ask, “Can we do this?”. Crews that have been conditioned to the reasoning that says, “if it is allowed it is safe” are being unknowingly exposed to many threats. Standard procedure cannot and should not be expected to cover all threats all the time. The environment is too complex and too dynamic.
Technical knowledge, procedural compliance and good piloting ability are all essential tools for maintaining a safe operation. Threat and Error management skills are responsible for ensuring the tools are applied in an effective manner for a positive outcome. The most effective operators don’t just talk about Threat and Error Management; it is fundamental to their entire operation.“Sorry Charlie, Starkist wants tunas that taste good, not just tunas with good taste. “