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Taking the bad fuel news with the goodTaking the bad fuel news with the good

Earlier issues of Flight School Business noted, first, the sharp decline in accidents caused by fuel mismanagement between 2000 and 2008, and then, not quite a year later, an increase of nearly 20 percent over the two years that followed. The first story also noted that 10 percent of all fuel management accidents occurred on training flights. That placed instruction a very distant second (behind personal aviation) in the number of fuel-management accidents.

Those figures were based on 20 years of accident data. However, yet another article noted that the fuel-management picture was changing during that time: Newer airplanes seem to be far less susceptible to exhaustion or starvation than older examples of the very same models. This suggests that those 20-year aggregate figures may mask real evolution in the way pilots assess and manage that particular risk. A closer look at the data confirms that the record of the 1990s looks quite different from that of the following decade, too much so to attribute the improvement solely to new technology.

First, a little context: There were 12,887 noncommercial fixed-wing accidents between 2002 and 2011, down from 15,845 between 1992 and 2001. That’s a 19-percent reduction, but most of it is explained by decreasing flight activity. However, the improvement in fuel management was considerably more dramatic. The number of fuel-mismanagement accidents dropped 39 percent, from 1,660 in the earlier decade to 1,018 in the most recent one. They made up more than 10 percent of all fixed-wing GA accidents from 1992 to 2001 but less than 8 percent between 2002 and 2011.

The fixed-wing training record also seems to have improved a little faster than noncommercial GA as a whole. Because of some quirks in the way the NTSB identifies instructional flights, these figures aren’t quite as reliable, but taken at face value they suggest nearly a 25-percent improvement, from 2,330 down to 1,760. The proportion of all accidents reported to have taken place on training flights decreased only slightly, from just under 15 percent to a little less than 14 percent.

The real payoff, though, comes when we narrow the focus to fuel-management accidents during training flights. There were at least 193 of these between 1992 and 2001; these made up 8 percent of all instructional accidents and almost 12 percent of all accidents caused by fuel mismanagement. The following decade only recorded 75, more than a 60-percent reduction. They accounted for just over 4 percent of instructional accidents and 7 percent of the fuel-management caseload. Moreover, the improvement wasn’t just steady—it actually accelerated. Over successive five-year periods, the counts dropped from 109 to 84, then down to 50. Between 2007 and 2011, there were only 25—so over a 15-year period, the industry’s susceptibility to this particular kind of goof-up fell a whopping 78 percent.

So what’s the bad news? (Aside, that is, from the fact that fuel exhaustion, starvation, contamination, and flooded engines still happen on training flights at all.) Well, it is a little discouraging that fully 60 percent of them happened while an instructor was on board—45 of the 75 in the past decade. Worse, the majority of those were during dual instruction toward advanced ratings, or during flight reviews or new-model transition training. In no fewer than 28, the pilot under instruction held at least a private certificate, meaning that between them, two supposedly competent pilots still managed to lose track of (or distract one another from) their fuel supply. Only 17 accidents took place in dual instruction of primary students—the activity that, according to an informal local survey, occupies maybe 80 percent of the typical line instructor’s time.

Of the remaining 30 accidents, 27 were on solo flights by student pilots. Two-thirds of them were cases of complete fuel exhaustion attributed to the students’ failures to calculate their fuel requirements accurately or keep track of fuel consumption during flight. More than half the accidents during dual instruction, on the other hand, were the result of errors in managing the equipment—most often a failure to change tanks in time to keep an uninterrupted supply flowing to the engine(s). Surprisingly often, both the instructor and the pilot being taught became so preoccupied with setting up for an emergency landing that they neglected to even try switching to another tank. Another handful were attributed to engines that flooded because boost pumps were used when they shouldn’t have been.

On the one hand, very few aspects of GA can boast this kind of improvement in their safety record. On the other, is it too much to ask that every CFI remember to switch tanks on every flight in every airplane that requires it?

ASI Staff

David Jack Kenny

David Jack Kenny is a freelance aviation writer.

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