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Don't become a case study!Don't become a case study!

Lessons from the 2010 Nall ReportLessons from the 2010 Nall Report

By David Jack Kenny

Professional statisticians hate the phrase “become a statistic” because it profoundly misuses their favorite word. A statistic isn’t an event; it’s a number that’s calculated from data. While the number “1” can be a statistic, a single case never is—it’s just a data point.

The 2010 Nall Report contains lots of statistics. What really brings things home for most readers, though, are the case studies, detailed accounts of how individual pilots got themselves (and, too often, their passengers) into trouble. The Air Safety Institute chooses them carefully in the hope that highlighting instances where the decision-making process clearly went awry will help other pilots recognize weaknesses in their own thinking. They’re not always representative, but they’re apt to prove instructive.

Several share the feature that “it seemed like the thing to do at the time”—never a good explanation to give investigators. Consider:

  • The pilot of a Robinson R44 was circling a mountaintop at a density altitude just about equal to its service ceiling and encountered a downdraft the machine couldn’t outclimb. As he tried to maneuver toward the valley floor, the helicopter caught a skid, rolled, and caught fire. Fortunately, he and his two passengers escaped without serious injuries, but the aircraft was destroyed.
  • A low-time VFR-only pilot tried to take two friends in an arc around the core of Class B airspace in a Cessna 182. There’s no evidence that he ever got a weather briefing. Ceilings were 1,500 feet when they took off, with two degrees between the temperature and dew point. As ceilings dropped to 300 feet and the visibility decreased to a quarter mile, the 182 crashed into a pond, killing all three. The airplane was shattered into fragments that are barely recognizable in the NTSB’s photographs.
  • A Beechcraft Baron pilot buzzing a friend’s ranch stalled it in from about 100 feet agl, killing himself and all four passengers.

Others betray an attitude toward flight planning that might generously be described as “casual”:

  • A Cessna 337 pilot chose to take off from a private field at night with no usable fuel in the two right tanks and less than five gallons combined in the left. He didn’t make it the 7 nautical miles to the airport where he had intended to buy fuel. Damage was so severe that the investigators couldn’t even determine the positions of the fuel selector valves.
  • Trying to get a Piper Lance with five on board off a 3,200-foot grass strip on a calm summer morning, the pilot left the flaps retracted. Performance data in the POH suggested that using 25 degrees would have shortened the takeoff roll by about one-third. The airplane never climbed out of ground effect before hitting a barbed-wire fence and then a tree.

Other mistakes were more subtle but no less catastrophic:

  • A high-time pilot flying a Bonanza cross-country before dawn crashed into the airport fence after mistakenly lining up with the perimeter road instead of the runway. The field had no weather facilities, and it’s not known whether either fog or pilot fatigue played a role.
  • An inexperienced pilot in a Piper Cherokee 140 flew a low pattern and landed after deciding that the airplane wasn’t making normal power. Finding nothing unusual during a run-up, he took off again, and then crashed attempting a teardrop turn back to the runway after power again seemed insufficient. The accident killed his father, a former FAA accident-scene investigator.

The fact that you’re here to read this means you made it through 2010. Congratulations! The next challenge is to get through 2011, preferably without contributing to the accident statistics. Even if forces beyond your control—a gear collapse, say, or a broken crankshaft—do put you in the database, the most important factor is entirely inside your own head. Keep planning carefully and thinking things through, and you can be confident that at least you won’t show up as a case study in the 2012 Nall Report.