Traditional Accident Investigation Taxonomy
Aviation accidents are investigated by both the National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA). The role of the NTSB is to determine the probable cause of accidents and make recommendations, while the FAA seeks to determine if the accident revealed deficiencies in pilot training, aircraft certification, air traffic control or another area of FAA responsibility. The two government entities are often assisted by other interested parties, such as aircraft and/or engine manufacturers, in an effort to determine the facts.
The NTSB role can be illustrated by looking at a typical accident report. [Figure 1] While this accident occurred several decades ago and the pilot had LORAN navigation, the lack of risk assessment by the pilot is typical. Pilots have confronted the same type of scenario and many have repeated similar behavior when faced with a significant and potentially lethal hazard.
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| Figure 1. NTSB Accident Report |
Key findings of the NTSB final report of the Mooney accident, highlighted in yellow, emphasized the pilot’s loss of control of the aircraft and inadequate in-flight planning. These facts accurately described the final events of the flight leading to the loss of control. In fact, conventional accident analysis classifies accidents such as this one as pilot error due to loss of control.
Risk Analysis Using the PAVE Checklist
The NTSB report on the Mooney accident reviews the accident facts to arrive at its probable-cause finding. Yet, there is more to learn about the root causality of the accident by examining the pilot’s reaction to events during the flight using the PAVE acronym from Defining Risk Management.
The pilot knew about the vacuum pump failure and the instrument meteorological conditions (IMC) ahead of him. The faulty equipment generated an aircraft, or “A” hazard and IMC generated an environment or “V” hazard. The combination of those two hazards created an unacceptable risk once the pilot decided to penetrate the weather. In addition, it is possible that the pilot’s desire to get to his destination created an external pressure, or “E” hazard. Finally, the pilot’s assumption that he could control the aircraft with critical instruments inoperative created a pilot, or “P” hazard. The risk assessment matrix [Figure 2], indicates catastrophic consequences were possible from loss of control in IMC, and the likelihood of loss of control after a vacuum pump failure, was at least occasional or even probable. Thus, the overall risk presented was high or red and needed mitigation of some kind.
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| Figure 2. This risk matrix can be used for almost any operation by assigning likelihood and severity. In the case presented, the likelihood of occasional and the severity as catastrophic falls in the high-risk area |
The pilot’s most effective mitigation may have been to divert and land while still in visual meteorological conditions (VMC). Why was the pilot unable to practice effective risk management on this flight? Lack of risk management training may have created an inability to cope with a difficult situation.
Instructors have a role and a responsibility to help pilots obtain the necessary risk management training and to adopt a safety culture that embraces risk management and mitigation of risk. The instructor’s role in risk management should be incorporated at all levels of training, from a new pilot with little experience to a multi-thousand-hour pilot taking recurrent training.
When to Teach Risk Management
The importance of risk management suggests that it should be taught at the very start of flight training and should be integrated into any actual flight training, rather than taught as a separate subject. However, it will be even more effective if the learner receives ground instruction on this topic prior to the first flight lesson. This preliminary instruction should also be part of any formal ground school.
Risk management activity and discussion should be included in all preflight and postflight briefings. Learners should be encouraged to participate and even lead such discussions as their experience increases.
Risk management training should not be confined to initial training. Recurrent, transition, flight reviews, instrument proficiency checks, and other training and currency events should also include risk management.
Identifying Risk
As described in Defining Risk Management, the PAVE checklist is an effective and accepted means for identifying risk. Its four categories capture broad areas of risk and provide the learner with convenient “buckets” for risk identification. Instructors should coach learners, as required, to ensure they use the PAVE checklist methodically and consider all the sub-elements in each bucket. For example, the “P” applies to both the learner pilot and the instructor pilot, and has two major sub-elements. The first includes pilot qualification, currency and proficiency. The second “P” sub-element covers aeromedical hazards and risks and, as described in Defining Risk Management, the acronym IMSAFE can be used to identify those hazards and risks.
Instructors should identify common hazards that generate flight risks. The PAVE checklist can be used to analyze each hazard for its level of risk. For example, the instructor can show that certain weather hazards are almost always “red” and create a need for mitigation when encountered. Examples include a solid line of thunderstorms ahead, or IMC before takeoff if the pilot is not instrument rated and current or the aircraft is not suitably IFR equipped.
The instructor should emphasize that risk can be effectively managed, and learners should acquire the necessary skills to accomplish this. In many cases, learners will be professionals who are used to managing risk in their workplace, although the hazards may be very different. Instructors should acknowledge the learner’s expertise in those areas. The instructor should involve the learner in aviation risk management decisions.
Assessing Risk
In some ways, risk assessment is the most difficult part of the risk management process. Assessing risk severity (consequences) and likelihood (probability) can be subjective during flight operations. In other aviation applications, such as aircraft certification, the likelihood of an event is calculated mathematically, and consequences are also precisely defined. Nevertheless, risk assessment accuracy can improve with practice and experience.
Instructors should initially lead learners through the assessment phase of each risk identified and provide examples that will help the learner gain confidence in risk assessment. For example, the instructor could suggest an event with a low but generally fixed likelihood, such as an engine failure after takeoff. The learner should consider the outcomes from various responses to that event. A review of the outcomes identifies the severity for the risk matrix.
Mitigating Risk
As explained in Defining Risk Management, risk mitigation is the “payoff” for the risk management process. Effective risk mitigation may allow for a proposed flight to begin or an ongoing flight to continue. However, this is not always the case, and the pilot should be prepared to delay or terminate any flight.
Instructors should teach that the risk management process begins days or even weeks before a specific flight. Early in the process, if a pilot identifies a risk that cannot be easily mitigated, such as a forecast weather system with widespread icing conditions, then the pilot can transfer the risk by getting an airline ticket. Alternatively, if the flight’s purpose is just recreational, then the pilot can eliminate the risk by cancelling the flight. Other examples of risk elimination include not flying if the crosswind exceeds a limit or not practicing stalls if the ceiling is below a set value.
Whenever a flight is contemplated, the process to mitigate each identified risk assessed as high (red) or serious (yellow) can begin. Instructors should emphasize to learners that medium (green) risks may be mitigated, if possible, following the principle of not accepting unnecessary risk.
Instructors should emphasize that even though risk management may begin days before a flight, it continues into the immediate preflight planning and throughout the flight itself. Instructors can plan to introduce scenarios in-flight that simulate hazards and ask the learner to practice how to identify, assess, and mitigate.
The final step in risk mitigation is to consider whether or not to accept the remaining risk. A pilot accomplishes this step consciously and on behalf of any passengers. During flight instruction, the instructor mitigates the risk associated with a learner’s actions by operating at a safe altitude and by guarding the controls. The instructor consciously accepts the risk that remains. Although the mitigation process completes, the instructor is vigilant for any hazard that needs consideration.
The acronym TEAM describes the steps in the mitigation process. TEAM represents transfer, eliminate, accept, and mitigate. These steps describe actions pilots take to deal with risk appropriately. During flight instruction, the instructor takes steps to ensure safety through risk mitigation and then operates with lower risk when the learner flies. Note that an unprepared learner constitutes a serious hazard. Prudent risk mitigation includes using a syllabus, providing quality ground instruction, and conducting a thorough briefing before each training flight.
Risk Management Tools
The risk management process is largely intuitive, but as with many new concepts, it can be daunting to the learner, especially at the beginning of training. Accordingly, the instructor should use available tools to simplify or make the process more orderly and effective.
The TEAM acronym and the risk assessment matrix discussed previously should be considered as primary tools for teaching risk management. Learners should be encouraged to use these simple tools as a basis for conducting risk management during and after their flight training.
On many flights, the risk management process can be more complex, and a more sophisticated risk management tool is needed. As discussed in Defining Risk Management, a flight risk assessment tool (FRAT) can serve this purpose.
There are a variety of FRATs available from various sources. Many of these FRATs have numerical scoring systems. A fixed list of hazards and associated risks are presented and assigned “scores” based on the severity of the hazard. Typically, if the total score is below a certain number, the pilot can begin the flight. If the score is above a certain number then some sort of mitigating action is required.
Numerical FRATs should be used with caution. A low score can still have one or more hazards and associated risks that, if not properly mitigated, can create unacceptable levels of risk. This can happen because a risk on a particular flight is not included in the FRAT’s list, or there is only one risk, but it is extreme. As an example, a line of embedded thunderstorms may block your route. If that is the only item identified as a risk then the “score” may suggest a “go” decision without requiring mitigation.