The Human Factor: Sliding into Risk

How to keep the chain of risk in check.

Sliding into Risk

Sliding into Risk

(June 2011) In last month's "Stuck for a Week," I wrote about how an extended delay can eventually lead someone to diminish or ignore what should be obvious risks. Another common cause of faulty risk awareness involves failing to "do the math." Risk factors seldom operate in isolation. Multiple risk factors will typically interact with each other, causing at least an additive effect, and often go far beyond that to multiply the total risk many times over.

For a simple example, let’s say you know the tires on your car are worn to the point where there is very little tread left. Because money is tight, you decide to defer purchasing new tires for a few more months. At that point every trip you take in the car carries with it the increased risk that you will skid if you have to stop quickly. A few weeks later it is raining hard as you hop in the car to do an important errand. Even with new tires, the wet roads increase the risk that you will skid, especially if you have to stop suddenly. However, with bald tires that risk is increased to the point that, if someone pulls out in front of you, you will not be able to stop in time and will find yourself staring at your crumpled wreck of a car, kicking yourself for not getting the new tires. The combined risk of the bald tires and the wet roads was much greater than the sum of the two separate risk factors.

Let's consider how we as pilots often find ourselves sliding down that same slippery slope of increasing risk. Imagine you are a low-time private pilot who recently received your instrument rating. You have been very busy at work, so you have had only one local flight over the last five months since you passed the instrument flight test. You have also noticed that the attitude indicator seems to be getting a little sluggish and have made a mental note to get it checked during the next annual inspection. None of this worries you much because you don't plan on taking any serious trips in the near future.

Then a friend suggests that you fly together on a weekend mountain fishing trip. Like your flying, your fishing has fallen prey to a busy schedule, so the chance to get away for the weekend while doing the two things you love is very enticing. You are, of course, aware of your low time and lack of recent experience, but a quick check of the weather forecast shows a fairly good weekend followed by rain and storms the following week. Since the weekend weather looks good, you enthusiastically agree and start planning the trip.

As you check the weather for your departure, you find that early effects of the coming storm are causing overcast clouds nearer your destination. You figure that’s not a problem, since you are still legal to fly IFR and will be flying only in instrument conditions en route. You launch with your friend on a beautiful clear morning but soon encounter the thickening clouds and have to concentrate on flying the airplane despite your rusty scan. You are glad the weather at the destination is supposed to be VFR so that an instrument approach won’t be necessary.

As you approach the destination, you are surprised to find that the weather in the mountains is much worse than forecast, and it looks like you will have to fly an instrument approach. At least the weather is still well above minimums, so that should not be a problem. You get out the approach plate and carefully study the approach, trying to remember everything you were taught during your instrument training while keeping the airplane on track and following the instructions of the controller. It is getting harder and harder to keep up with everything, let alone stay ahead of the airplane.

Just when you feel like you are hanging on by your fingernails, and are counting the minutes until you are safely on the ground, the attitude indicator gradually tilts over to one side. You desperately try to remember the partial panel flying you did during your instrument training, but it is all too much to handle, and soon you find yourself desperately hauling back on the control wheel as the airspeed indicator winds up and the altimeter winds down. It is all over in a matter of seconds.

This same scenario has been replayed thousands of times with different sets of details. Typical risk factors include:

Lack of overall experience.
• Lack of recent experience.
• Little or no time in type.
• Fatigue.
• Known mechanical issues or failures.
• Loading the airplane over maximum gross weight.
• Loading the airplane out of the CG envelope.
• Departing without enough fuel.
• Headwinds that increase the amount of fuel needed.
• Failure to check the weather.
• Weather worse than forecast.
• Failure to assess runway requirements.

In each case, one risk after another is either ignored or accepted over the course of a flight. Each individual decision may seem fairly reasonable at the time, but taken in the context of the previously accepted risks, the pilot is accumulating an unacceptable level of total risk. All it takes is one unanticipated event for the entire house of cards to come tumbling down.

The best way to avoid this scenario is to carefully keep track of each decision you make and maintain an accurate tabulation of all risk factors previously accepted, with a rough idea of the total risk at that point. If you make a decision based on certain parameters, also set a “no go” or “turnaround” value for that parameter. In the hypothetical example above, the pilot could have decided that, due to his lack of total, instrument, mountain or recent experience and the sluggish attitude indicator, he would not depart or would turn around if it looked like he would have to fly in instrument conditions.

When reading accident reports, it is often heart wrenching to watch the steady accumulation of risk until it reaches the point where an accident is inevitable. The challenge is to have "hindsight in foresight" and be aware of the growing chain of risk as it is happening. With each new decision you face, go over your mental or written list of risk factors, not only assessing the total accumulated level of risk, but also considering how various risk factors might interact to quickly make the situation much worse. To fight the common tendency to do some "wishful thinking," maintain an attitude of aggressive skepticism, always considering the potential consequences if the weather is worse than forecast or an intermittent problem finally becomes a permanent failure.

Often there are alternative solutions available that allow the trip to be completed safely. For example, there might be an airport at a lower elevation outside the mountainous terrain where the weather would remain VFR throughout the weekend. The pilot and his friend could land there and rent a car for the remainder of the trip into the mountains, thus allowing them to still enjoy the weekend fishing trip while holding to the pilot’s commitment not to fly in instrument conditions. Even if that is not possible, keep a rational perspective on risk versus benefit. Remember that the fish will still be there next week, and that whatever is driving your relentless pursuit of making it to the destination is probably not worth dying for.