Cirrus Safety and Risk Homeostasis
The Cirrus aircraft is loaded with advanced safety features lacking in older "legacy" aircraft. Yet, the Cirrus safety record appears to be no better -- and perhaps even worse -- than that of the legacy fleet. How can this be?
I've written before that "risk homeostasis" may be one factor at work. I suggested here and here that pilots might tend to use the advanced features of the aircraft to fly into more challenging conditions than they otherwise would. While using the features in that fashion might increase the utility of the aircraft, it necessarily undercuts many of the features' safety benefits.
It turns out that that three human factors experts have published a short article (see below) on risk
homeostasis theory as it applies to technologically advanced aircraft. I discussed the article recently with one of the authors, Steven Meyers. I came away convinced that the theory deserves more attention than it has to date received.
Meyer's article explains risk homeostasis as follows:
If people assess the level of risk associated with a particular activity to be greater than the acceptable level, they tend to exercise greater levels of caution. . . The opposite is also true: If they assess the level of risk to be lower than their acceptable level, they tend to engage in actions that increase their level of risk taking.
What follows is that, when provided with a safer airplane, a pilot may simply chose to "push harder."
If the level of risk for a particular activity is somehow reduced, [the participant] may react by increased risk-taking to return himself to an "acceptable level".
Risk homeostasis theory explains why pilots who are experienced in legacy aircraft wouldn't be any safer when they fly the Cirrus.
But what about the cadre of new pilots who were drawn to aviation by the Cirrus' safety features? By standing on the sidelines until the safety features were introduced, those pilots demonstrated that the Cirrus provides the highest level of risk that they are willing to accept. Risk homeostasis theory wouldn't suggest they would engage in riskier behavior because of the plane's novel safety features. Therefore, one might expect that their safety record would be better than that of equally experienced pilots flying legacy aircraft.
Yet, that doesn't seem to be the case. That means other factors must also be at work.Pilot Error and Technically Advanced Aircraft
Nice overview of an issue that goes far beyond aviation. Tom Vanderbilt discusses the issue of perception of risk in his book "Traffic". Several towns in Europe have experimented with deliberately removing safety features (stoplights, signs, speedbumps, crosswalks, etc.) to make road users perceive more risk. Result? Crashes and injuries dramatically reduced. Making the road appear unsafe actually resulted in a much safer road. Rather counter-intuitive.
Antilock brakes are another famous example. They've done nothing to reduce automobile crashes. Drivers simply compensate by going faster, following closer, to maintain the same level of risk perception.
In response to your last question--why are new pilots of advanced aircraft no safer than new pilots of legacy aircraft?--my answer is that experience and good judgment matter in developing a proper perception of risk. The legacy aircraft appear less safe, so pilots take fewer risks. The Cirrus (and similar advanced aircraft) appear safer, but actually aren't, but that appearance of safety results in poor decision-making.
My personal opinion is that pilots develop judgment by being exposed to hazardous situations and getting the crap scared out of them. Unfortunately, it's very difficult to show a pilot the dramatic results of airframe icing, for example, without a simulator. Same for penetrating a storm cell or squall line, or simply for flying at night over sparse terrain or water (removing the visible horizon offered by city lighting).
One does not develop good judgment by training ab initio in a glass-cockpit aircraft. One simply learns how to use all that new fancy stuff, often at the expense of learning to fly using basic airmanship. Good judgment matters far more than fancy and expensive instrumentation and displays.
Cloudesley-
Thanks for the tip on Vanderbilt's book. It's going on my reading list.
Mike