Page 38 - Volume 15 Number 10

the conclusion that somewhere along the line a pilot made a bad decision. In the vast majority of cases however, pilots will make dozens of decisions throughout the course of a flight that don’t end in tragedy. Researchers have spent decades developing and refining aviation decision-making models in an attempt to show how to make the best decisions. Although the most popular models vary slightly, most begin with identifying the problem, collecting facts, and identifying alternatives. The alternatives are weighted – given some sort of relative value from the standpoint of the decision-maker – and analyzed against safety of flight criteria. The choice is then implemented and evaluated for efficacy.This method is typically referred to as rational or optimum decision-making in that the option that generates the highest overall weighted score is considered to be the best decision. A good decision occurs when the pilot selects that option in lieu of another lower value choice.As an example, imagine that you are planning a weekend ski trip to a resort destination. You’ve worked all week and are somewhat fatigued as the departure time approaches on Friday evening. Fortuitously, the resort is equipped with its own 5,000-foot-long lighted runway eliminating the need for transportation upon arrival. However, the runway is adjacent to rising terrain and served by a VOR approach with minimums of 500 feet AGL.The next suitable airport is 80 miles away, requiring a rental car and a long drive upon landing. The airport is served by a GPS approach with a localizer-like glide path to a 7,500-foot-long runway and an operating control tower. Weather conditions at arrival call for 700 overcast with two miles visibility in light snow. Both airports are reporting runways to be covered with packed snow and braking action has been verified as good.A pilot using rational decision-making would take into account all the variables including fatigue, runway length, aircraft performance capability, weather, terrain, and approach availability and make a decision based on which option was deemed to be safest. A third option is also available; cancel the trip entirely because of discomfort with both airports given the conditions.Although the rational choice method of decision- making has been highly promoted as a tool to enhance safety, it is based on some assumptions that make it cumbersome to use in real-time flying operations. One pitfall is that it is extremely time consuming to take into account all the parameters of the situation and subsequently evaluate them. Along the same lines, rational choice decision-making requires all the options and the associated information to be known and well understood. In the previous example, if the runway conditions could not be obtained before arrival, a decision36 • TWIN & TURBINEOCTOBER 2011