The last issue of Flight School Business suggested that training accidents in special light-sport aircraft (LSA) look pretty similar to other training accidents. If you buy that, you probably won’t be too surprised to hear that the patterns that are starting to characterize LSA accidents in general don’t seem very different from those we see in other fixed-gear singles, and those few differences that do emerge appear to reflect their underlying patterns of use.
Of the 133 LSA accidents recorded between 2006 and 2010, 53 (40 percent) were landing prangs. This share is about one-third larger than for piston singles overall, where about 31 percent of all accidents were landings gone bad. Collectively, takeoffs, landings, and go-arounds made up 58 percent of the LSA accidents compared to 44 percent of those in the larger fleet. But these are the typical mishaps of primary instruction, and we noted last time that a disproportionate number of LSA accidents happened during training flights.
Likewise, LSAs see correspondingly fewer of the types of accidents more associated with cross-country travel. Adverse weather, fuel mismanagement, and other problems during cruise flight and the descent to pattern altitude caused only 8 percent of LSA accidents (11), barely half the 15 percent share in other piston singles. Mechanical failures were actually less common in LSAs, but there were relatively more unexplained losses of engine power, a combination that may reflect differences in investigator experience with the powerplants involved. Taken together, mechanicals made up 17 percent of LSA accidents, about the same as the 20 percent in the rest of the fleet.
Of course, piston singles are still a pretty diverse group of airplanes, encompassing everything from an operational replica of the 1905 Wright Flyer to unlimited-class Reno racers to the 12,000 lb. AN-2 biplane. Load-haulers such as the Cessna StationAir and Piper Cherokee Six and fast cross-country machines like the Cirrus SR22 and Cessna Corvalis don’t have much in common with the offerings of Flight Design or Remos in terms of mission, flight characteristics, or operational environment. If we further restrict our attention to two-seat fixed-gear models operating in daytime VMC—and eliminate homebuilts, whose characteristic accident patterns differ noticeably from those of manufactured airplanes—the blend of accident types in the LSA record looks even more similar to that of traditional models.
Takeoffs, landings, and go-arounds jointly made up 49 percent of all accidents in legacy two-seaters, while weather, fuel mismanagement, and miscellaneous accidents during cruise and descent accounted for just 11 percent. The combination of known mechanical failures and unexplained losses of power were still good for 20 percent. Accidents during maneuvering were not only less prominent in the LSA record, but substantially less lethal: only one of seven was fatal compared to 34 of 70 (49 percent) in type-certificated models.
Of course, while LSAs appear to have the same types of accidents in about the same proportions as other two-seat fixed-gear piston singles, they do still seem to have more of them. Better estimates of the accident rates will be possible after the FAA publishes its 2010 General Aviation and Part 135 Activity Survey this fall, but available data suggests that so far, LSAs suffer more than three times as many events that require reporting under Part 830 in a given number of hours flown. Still up in the air is the extent to which this reflects lack of familiarity with the aircraft, greater susceptibility to structural damage when handled less than perfectly, or other factors altogether.
David J. Kenny is manager of aviation safety analysis for the Air Safety Institute and an instrument-rated commercial pilot.