Earlier this year, AOPA Pilot attended FlightSafety International's Cockpit Resource Management workshop. One of the more intriguing discussions led by Douglas Schwartz, FlightSafety's assistant director of standards, concerned a subject Schwartz calls "the safety window."
The safety window is a block of airspace that extends from the ground to 2,000 feet agl. The window is centered on a runway; it begins at or near the final approach fix and extends through the approach, landing, and takeoff phases of flight and terminates when the takeoff climb passes through 2,000 feet, often a time of transition to the cruise climb segment.
We are used to seeing statistical models of aviation safety that divide flight up into segments and analyze accidents and incidents according to phase of flight: takeoff, climb, cruise, descent, landing, and so on. Schwartz believes that by looking at the safety window and its associated operations as a whole, some patterns emerge that are not otherwise readily apparent.
The safety window comprises those phases of flight in which the majority of accidents occur, in this window, pilots are also confronted with the highest work load of a flight. If something goes wrong inside the safety window, a pilot has little time in which to react, but his reaction has immediate consequences to the successful outcome of the flight.
FlightSafety's analysis, which concerned mostly corporate flight operations, yielded three significant observations. First, the safety window is only four to six minutes long when flown in a conventional turboprop or jet airplane. Second, 83 percent of the accidents involving professional pilots occur within the safety window. Third, 90 percent of those accidents are "generic" in the sense that their causes are not airplane-specific; e.g., improper speed control is a function of pilot action independent of the specific type of airplane involved. Generic accidents and incidents tend to be pilot-related rather than aircraft-related.
Does FlightSafety's safety window model apply to general aviation operations across the board, beyond just the corporate arena? According to the AOPA Air Safety Foundation's aviation safety database, which now includes more than 15,000 accidents that took place between 1982 and 1987, it does. The ASF database shows that 65 to 75 percent of all the pilot-related general aviation accidents examined took place in (or near) the safety window (ASF figures do not draw an arbitrary distinction at 2,000 feet agl, hence the qualification). Here, too, many of the accidents appear to have been generic — "A predominance of landing accidents," one ASF report notes, for example, "involved improper speed control (too slow to avoid settling in gusts/crosswind conditions; too fast to avoid overshoot)."
Obviously, the length of time a typical light airplane spends in the safety window is longer than that of a turboprop or jet. What is true regardless of aircraft type, however, is that the pilot's work load is highest within the safety window. Check lists; speed management, operation of gear, flaps, and fuel systems; ATC communications; transition from instrument to visual flight (or vice versa); traffic avoidance; aircraft maneuvering; and a host of other tasks demand the pilot's attention. As work load increases, the opportunity to make a mistake increases and the time available to rectify a mistake decreases. Therefore, the results of pilot action or inaction are often more critical in the safety window than in, say, cruising flight.
A point should be made regarding action and inaction. An action can be appropriate or not, a proper response or a mistake. Likewise, inaction can be the failure to do something that is needed, or it can be the result of a conscious wait-and-see decision. The trick is learning to catch the mistakes before they get out of hand and determining whether positive action is needed to change the potential outcome of a situation. Some decisions require little if any thought: Presumably, for example, we begin every approach with the expectation of executing a missed approach at the appropriate time. Other decisions need to be made "on the fly," so to speak, as conditions warrant: The appropriate response when an engine of a light twin quits inside the outer marker is less easy to anticipate than a missed approach; it is dependent on the specific circumstances.
Given that most accidents occur in the safety window and that work load there is very high, wouldn't the appropriate response always be to get out of the safety window, get stabilized, reduce distractions, take stock, and sort things out? Or should the pilot, confronted with an emergency or problem while in the airport environment, simply put the aircraft on the ground as soon as possible and figure out what went wrong later?
FlightSafety experimented with this question in its simulators. According to Schwartz: "In a study of flight crews using a Bell 222 [helicopter] visual/motion simulator, pilots were given a catastrophic tail rotor failure shortly after liftoff. Those instructed to land immediately upon encountering the failure crashed in more than 80 percent of the cases. However, pilots instructed to climb to a safe altitude and stabilize there until they felt most prepared to land crashed less than 20 percent of the time. In this case, it is clear that leaving the window is the best choice. Fewer accidents resulted.
"However, consider another case: A twin-engine jet aircraft on half- mile final with a clearance to land suddenly has an engine fire warning. The aircraft is configured to land, is stable, and both engines appear to be operating normally. The crew elects to complete the landing and wait until the aircraft is on the ground to attend to the fire warning. Most would agree that landing rather than going around is the best option. In this instance, it is best to remain in the safety window."
In the latter instance, would the same be true if the crew were flying a piston-powered twin or if the engine in question did not appear to be operating normally? Sharpening the skills that enable us to make such judgments quickly and accurately is what training — both initial and recurrent — is all about. Complacency dulls our judgment and decision-making skills because it deprives us of the information we need to make well-informed decisions.
We are all aware of the importance of determining an airplane's weight and balance and the risks posed by high density altitude conditions. When was the last time, however, that you actually computed the weight and balance for a flight and took into account temperature, pressure, runway slope and surface, and wind in making a takeoff decision? Likewise, we all know the maneuvering speed of our airplane at maximum gross weight (on most airplanes, it's placarded), and we know maneuvering speed goes down as weight goes down, but could you, upon encountering severe turbulence, quickly and accurately determine the appropriate maneuvering speed at a reduced weight, given the other distractions to your attention at such a time?
The key to judgment is situational awareness — knowing what's going on around you at all times. This means not only having all available information about the specific flight at your fingertips, as required by the regulations, but also having a thorough knowledge of the systems and capabilities of the aircraft. And it means you are obliged to remain current and proficient — on regulations and procedures as well as on approaches, night landings, and what have you.
It also means being aware of the safety window. If you wish, you can define a safety window around any phase that you feel should demand extra attention — a higher level of situational awareness from the pilot. ASF database figures show, for example, that fuel mismanagement (either running out of gas or not properly husbanding what is in the tanks) accounts for 10 percent of all pilot-related accidents. You can build a safety window around fuel management tasks that will help to focus your attention on making sure caps are tight, gaskets are sound, fuel is uncontaminated, crossfeeding is properly accomplished, tank switching is performed on schedule, flight is never continued after predetermined minimum fuel levels are reached, and so on.
In coming months, you will see pilots emerging from ASF safety seminars wearing a button with the ASF logo and the legend "4.5 in '95." That refers to ASF President Donald D. Engen's determination to cut general aviation's accident rate from 1989's approximately 7.25 to 4.5 accidents per 100,000 hours flown by 1995. A greater emphasis on developing and maintaining situational awareness — inside and outside the safety window — on the part of all pilots will go a long way toward reaching that goal.
