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. “
