On Aug. 24, the Air Safety Institute released the twenty-fourth edition of its Joseph T. Nall Report. This comprehensive analysis of general aviation accidents during 2012 presented an overall picture very similar to those that characterized 2011, 2010—and, well, you get the idea. (One thing, however, was new: For the first time, the Air Safety Institute was able to categorize the causes of helicopter accidents. See pages 13 through 15.)
In particular, accident rates—defined as the average number of accidents during some standard measure of exposure, such as per 100,000 flight hours—for both airplanes and helicopters stayed about where they have been since at least 2006, the last of five years of encouraging improvement in helicopter (but not fixed-wing) safety. Since then, however, we’ve seen only random fluctuations in what appears to be a stationary process.
Rates seem to be widely misunderstood, so it’s worth taking a few minutes to get them in focus. If the accident rate—the average number per 100,000 hours—doesn’t change, then fewer hours flown would produce correspondingly fewer accidents. A 5-percent decrease in flight time would cut the accident count by that same 5 percent. This is why it’s nonsense to argue that a lower rate results from diminished activity: That change in activity is already factored into the computation. For the rate to go down as flight time drops, the number of accidents would have to fall faster than hours flown. That can happen (spoiler alert!), but the opposite is more intuitively plausible. If fewer hours flown equates to generally lower proficiency, we’d expect that growing rustiness to cause accident rates to rise.
Returning to 2012, the overall numbers and rates weren’t the only things that didn’t change much from prior years. The causes of fixed-wing accidents were almost exactly what we’ve come to expect. Nearly half were ascribed to poor technique during takeoffs, landings, and go-arounds. Less than 15 percent were caused by known mechanical failures (and another 6 percent by engines that quit working for no obvious reason). VFR into IMC, deficient instrument flying, and aggressive low-altitude maneuvering remained among the most common causes of fatalities, but fuel management did show a welcome improvement. Personal flights again contributed disproportionately to both the airplane and helicopter tallies. Instructional flights accounted for about 15 percent of fixed-wing and 23 percent of helicopter crashes, both comfortably within the range observed throughout the preceding decade.
If the Nall Report looked like another example of “The less things change, the more they stay the same,” there was real excitement in the shorter report that accompanied it, the Air Safety Institute’s 2013-2014 GA Accident Scorecard. While there’s not yet enough information available to do a detailed analysis of the record of the past two years, the scorecard breaks out everything that’s known with reasonable certainty early in the investigative process—things such as the type of aircraft involved, the purpose of the flight, basic light and weather conditions, and the pilot’s certificate levels.
The previous scorecard showed a sharp and completely unexpected drop in both accidents and fatalities on noncommercial flights during 2013—especially in airplanes, where they reached record lows. At that time, it was impossible to say whether this represented a real improvement or just an acceleration of the decline in hours flown. Two developments since, however, have shown that the 2013 numbers are reason for genuine optimism. The current scorecard, as its title implies, contains summary data for 2014—and the 2013 activity survey results needed to figure that year’s accident rates.
By almost every measure, 2013 was the best year for GA safety in at least a half-century—and 2014 saw further improvements in every sector except noncommercial helicopter (where the total increased by one). The combined number of fatal accidents in 2013 was 18 percent lower than in 2012, while a 6-percent increase the following year meant that 2014’s total was only the second lowest on record. And, while 2013’s total accident count (fatal and nonfatal) also dropped by an unprecedented 18 percent from the year before, estimated flight activity “only” decreased by 6 percent. We saw fewer accidents because pilots did a better job of preventing them, not because no one was flying any more. The accident rate on noncommercial fixed-wing flights was the lowest since the Air Safety Institute began tracking this figure in the early 1990s, while the corresponding fatal-accident rate dropped below 1.00 for the first time.
Naturally, the question that leaps to mind is whether this was the product of general improvements across the board or the result of big gains concentrated in a few specific areas. We’d love to tell you—but we’ve run out of space for this issue. Stay tuned!
David Jack Kenny is manager of safety analysis for the AOPA Air Safety Institute.
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