Aeronautical Decision-Making and Risk Management

Aeronautical decision-making (ADM) is the process by which pilots decide what to do, from the choice of whether to fly at all to the handling of a diversion or an emergency. Risk management is its companion: finding the hazards of a flight, judging how much risk each one carries, and reducing that risk until it is acceptable. Good decisions depend on good situational awareness, and good awareness is wasted without them.

Poor judgement and poor preflight planning and decision-making are among the most common causes of pilot-induced accidents. Structured decision-making is the response: the FAA teaches it to all pilots as aeronautical decision-making, and airlines build decision models into their crew resource management training. It is examined in the EASA Human Performance and Limitations (040) syllabus and in the FAA knowledge tests, where the models, checklists and acronyms below are asked almost word for word.

What ADM is

Human factors texts distinguish deciding, which may be arbitrary or emotional, from decision-making, a step-by-step process towards a balanced, factual choice. The Judgement Concept summarises what that process weighs: judgement, risk assessment and the resulting decision are based on the pilot, the aircraft, the environmental conditions and the time available. The same concept names a point of commitment, the point of no return in the decision sequence, after which a chosen course can no longer be reversed.

A decision is only good if it can be carried out in the time available. Contrary to popular belief, time in flight rarely forces a very quick decision except close to the ground, at take-off and landing, and crews can usually make time by holding, going around, delaying the take-off, reducing speed or diverting. Aviation therefore uses two methods. Predictable problems, such as an engine fire, get a standard operating procedure worked out in advance by experts. Complex, unpredictable problems for which no procedure can be written get a structured decision model. Whatever the method, the aircraft commander is ultimately responsible for every decision made on the flight deck.

Analytical and intuitive decisions

Analytical decision-making generates several options, compares them against the facts and chooses the best. It produces the best result when there is time, but it is slow and makes heavy demands on working memory, and decisions made under stress, fatigue or overload are rarely of high quality.

Intuitive decision-making matches the situation to a familiar pattern and acts on the first workable response. The psychologist Gary Klein described it as recognition-primed decision making (RPD): experts recognise a situation as typical of something they have met before and mentally simulate a single course of action rather than comparing many. Experience speeds diagnosis through pattern recognition, which is why a lack of experience slows the whole decision process. Trained memory drills turn time-critical events into rule-based responses: after an engine failure just after take-off in a light twin there is no time to analyse, and the drill must already be known.

Preparing a decision in advance, through thorough flight preparation and a briefing before each high-risk phase, is the best protection against deciding under time pressure. It carries one risk, the error of commission: a prepared response can be triggered by the wrong stimulus, so the stimulus should be cross-checked before acting.

US Airways Flight 1549, an Airbus A320, struck a flock of Canada geese while climbing out of New York LaGuardia on 15 January 2009 and lost thrust in both engines below 3,000 ft. The captain took control, the first officer began the engine restart checklist, and within minutes the crew judged that neither LaGuardia nor Teterboro could be reached and ditched on the Hudson River. All 155 on board survived. The NTSB concluded that the captain's decision to ditch on the Hudson rather than attempt to land at an airport provided the highest probability that the accident would be survivable.

Decision models: DECIDE, FOR-DEC and DODAR

Structured models slow a stressed crew down enough to separate diagnosis from choice. All of them are loops, not lists: the final step checks whether the decision is working and returns to the start if the situation has changed.

In DODAR, Assign shares the workload among the crew and outside agencies, and Review keeps asking whether anything has been missed or has changed. For non-urgent decisions the captain should invite the crew's ideas before stating his or her own, because a junior colleague may not voice a view that seems to contradict the captain. Once the decision is made, a good commander explains the reasons.

For the first seconds of a surprise, some operators teach a deliberate pause, often as STAR (stop, think, assess, then react or respond; the expansion varies), taking a breath before the first action so that the response is chosen rather than reflexive. Memory items and the aviate, navigate, communicate priority come before any structured model.

Assessing risk

FAA risk management separates a hazard, a present condition, event or circumstance that could lead to an accident, such as a thunderstorm or a fatigued pilot, from risk, the future impact of a hazard that is not controlled or eliminated. Risk assessment judges each hazard by two separate measures, the likelihood of an event and the severity of its outcome, often on a matrix:

• Likelihood: probable, occasional, remote, improbable.
• Severity: catastrophic, critical, marginal, negligible.
• Result: high, serious, medium or low risk.

Scoring the two measures separately stops a remote but catastrophic hazard, such as icing in an aircraft not approved for flight in known icing, from being dismissed as unlikely. A flight risk assessment tool (FRAT) is a numeric version used by many operators: it scores factors such as pilot experience and rest, weather, airport and night, and a high total calls for mitigation or a second opinion. It forces the pilot to add up small risks that seem acceptable one by one.

European human factors texts also distinguish objective (external) risk, the risk of an accident if nothing about the situation changes, from subjective (internal) risk, the crew's inability to carry out a solution through lack of know-how or of time. Subjective risk grows as a deadline approaches. People are poor judges of probability in any case, which is one reason for writing the assessment down (see cognitive biases).

The 3P model: PAVE, CARE and TEAM

The FAA's 3P model is a continuous loop run throughout a flight:

1. Perceive the hazards, usually with the PAVE checklist: Pilot (health, currency, fatigue, experience), Aircraft (equipment, performance, airworthiness), enVironment (weather, terrain, airport, airspace, night) and External pressures (schedules, passengers, money, the wish to get there).
2. Process their risk with the CARE checklist: the Consequences of each hazard, the Alternatives available, the Reality of the situation and the External pressures acting on the decision.
3. Perform with TEAM: Transfer the risk, for example by consulting someone better placed to decide; Eliminate the hazard; Accept a risk whose benefits outweigh its costs; or Mitigate it by reducing its likelihood or severity.

Each action changes the situation and may create new hazards, so the loop starts again. A pilot's own fitness is often checked with IMSAFE: illness, medication, stress, alcohol, fatigue and emotion.

The 5P check reviews the plan, the plane, the pilot, the passengers and the programming of the avionics at natural decision points: before the flight, before take-off, hourly or at the midpoint, before descent, and just before the final approach fix or the traffic pattern. Programming is included because head-down time setting up avionics is itself a hazard in single-pilot flying.

Personal minimums

Personal minimums, or personal minima, are limits a pilot sets for weather, wind, fuel reserves, night flying and personal condition, more conservative than the legal minimums. FAA guidance recommends starting from the legal and aircraft limits, adding a margin based on experience, currency and the type being flown, and writing the result down. They tighten after a period without flying, on a new type or in a new kind of operation; the answer to a long lay-off is easier conditions or a safety pilot, never a lowered standard. They are revised only after reflection on the ground, never in the air.

Go/no-go decisions

The go/no-go decision before departure is where most risk can be removed at least cost. The PAVE review, the IMSAFE check and the weather are compared with the personal minimums, and external pressures, a waiting customer, a family event, the last flight home, are treated as a hazard in their own right, because they are the element most often left out and the one most likely to override the other three.

Decisions made in advance, and written down, are less exposed to pressure than decisions made at the aircraft or in flight. Effective defences are a decision time for cancelling, diversion criteria fixed before departure, telling passengers beforehand that the weather decides the schedule, and, for commercial operators, a published no-fault delay and diversion policy. Legality is the floor, not the target, and the responsibility for the decision cannot be handed to ATC. The same principle carries into the air: reaching a personal minimum means turning back or diverting, not renegotiating it.

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Library articles are written for study and exam preparation. They do not replace your aircraft's approved documentation, your operator's procedures or the regulations themselves.