Assessing a trip’s risk 

Pilot’s primer
by Donald Talleur

What level of risk assessment do you generally engage in prior to going on a flight? If your answer is none, or you’re not really sure what "risk assessment" means, then please read on!
Take a moment to think about the flights you’ve made over the past few years. Have you run into any circumstances that were not expected, flown over unfamiliar terrain, tackled questionable weather, or flown into unfamiliar airports? Undoubtedly, most of you have experienced one or more of the above.
Risk assessment is the process of attaching tangible or intangible values to various aspects of your flight. Weights are typically applied according to the perceived risk associated with a particular aspect. For instance, if you’re flying to an airport that has only non-precision approaches and the weather is forecast to be quite poor, one might attach a relatively high value (high risk) to this scenario. But this is a simplistic example. What really goes into the assessment deals with many more details of the flight.
Consider the scenario I proposed above. Are you expecting radar vectors for the approach, or will you have to do a full approach without radar guidance? Is the airport located near mountainous terrain? Will the flight take place during daylight or at night? Are you flying it alone or with a partner? Hopefully, you should begin to realize that there are a lot of factors that need to be considered when assessing the overall risk of a flight.
How does a pilot calculate the actual risk of a planned flight? Well, it’s not certain that anyone has devised a foolproof method of doing this yet. Clearly, there are interactions between various risk factors, as well as the pilot’s experience and physical condition prior to the flight. A practical way of looking at this dilemma is to envision the safest flight you could possibly plan. A day VFR flight over familiar terrain and to a familiar airport, within a short distance from your origin airport, might suffice as an example of a routine low risk flight. Then, consider the level of risk associated with that flight. Now, carefully consider the real flight you have planned. Any deviations from that "safest" flight profile might flag an increase in risk and should be noted. These deviations can be thought of as adversities, such as flying in the clouds instead of clear skies. The more deviations you chalk up, the more carefully you should plan for the trip. This is not an exact science, but rather a thought-provoking exercise that will hopefully eliminate potential oversights in the planning process.
So far, I’ve mentioned several risk assessment factors, but how does the pilot know which factors are relevant to him or her? What you may have to do first is determine your personal minimums for any given flight activity. To name a few, these include issues such as: how low of a cloud ceiling or visibility are you comfortable with, how familiar are you with your aircraft, and how much sleep do you require before a flight. Your personal minimums should be reviewed from time to time as your experience level changes. It’s safe to say that a newly-rated instrument pilot should not plan a flight that requires flying an ILS approach to minimums. Likewise, a new pilot should not test their skills by finding the shortest runway for landing on a rainy day. I’m sure there are some pilots who will tell you they did these things and didn’t experience any problems, but I’m also as sure that those pilots probably neglected to consider the actual risks involved with those operations.
What this all boils down to is spending a little time prior to your flight to really think about what you’re going to be doing. Since a pilot can be easily lulled into a false sense of security by the ratings and certificates that he or she holds, it is important to evaluate each flight separately and as objectively as possible. Do not let your past success in defying the odds influence your future success. A risky scenario that you happen to live through does not become substantially less risky just because you can say "I’ve done that."
In the end, it is also crucial to evaluate the importance of a given flight, if the risk assessment of that flight puts safety in doubt. All too often, "get-there-itis" drives decisions that end in a flight emergency or even an accident. If you feel any type of external stress or pressure to complete a flight, consider whether it is worth having an accident or causing injury to yourself or others.
There are days when pilots should drive instead of fly, and there are days when flying is probably safer. If you practice some form of risk assessment, you might just be able to determine which days the plane is best left hangared!