On June 17, the Air Safety Institute published Accidents During Flight Instruction: A Review, which updates and extends the initial analysis of instructional accidents put out a decade earlier. Some of its findings may surprise you—they certainly surprised the writers! But even if there’s nothing in there you hadn’t already suspected, the report can help you add some numerical precision to those seat-of-the-pants risk-benefit calculations.
The industry’s long maintained that flight instruction is one of the safest sectors of general aviation. How strongly the numbers back that up depends on what aspect of “safety” you choose to examine. In both airplanes and helicopters, the rate of fatal accidents per 100,000 hours flown during training is less than half the rate on noninstructional flights—and the noninstructional rates are tamped down by the corporate and executive sector, in which fatalities are almost unknown. Similar results apply if you compare the rates of accidents causing either deaths or serious injuries. So if you’re chiefly concerned about the risk of bloodshed, the results are reassuring.
On the other hand, differences in the rates of all accidents (as defined by Part 830) are far less dramatic. In airplanes, the overall accident rate is only about 10 percent lower on instructional flights. The chief reason there’s not more of a difference is the outsized number of accidents on student solos, which made up two-thirds of all primary training accidents and 45 percent of fixed-wing instructional accidents of all kinds. Eighty percent of them happen during takeoffs, landings, or go-arounds, which makes sense; controlling the aircraft at low speed close to the ground ought to get easier with practice. But for all their contribution to the total accident rate, students rarely suffer much more than a bruise or a scratch. Less than three percent of their accidents are fatal. Fatal accidents are actually concentrated in advanced instruction, which saw more than 60 percent even though it accounted for only 35 percent of accidents overall.
The causes of crashes on dual lessons look remarkably similar whether the person receiving instruction is a primary student or a certificated pilot. Takeoffs, landings, and go-arounds account for about half, while about another 20 percent are due to either mechanical failures or engine stoppages for reasons that are never satisfactorily explained. Fatal accidents are most common while maneuvering, though not necessarily in the maneuvers you might expect: Accidents involving stalls, for example, are almost unknown during stall training, but become a real hazard when drilling emergency procedures (especially simulated engine-outs).
Helicopter instruction presents an almost entirely different picture—except for the fact that there, too, the causes of dual accidents are very similar at both the primary and advanced levels. The estimated accident rate for the entire decade was actually 28 percent higher on instructional than noninstructional flights, though the results from the first five years are somewhat suspect: The FAA’s estimates of instructional flight time quadrupled over that relatively brief period. Rates over the last five years have been almost identical, but the fatal accident rate remains more than 50 percent lower on training flights.
Student solos only account for one-quarter of all accidents during primary training and less than 12 percent of instructional accidents overall. Advanced instruction leads to just over half, fatal and nonfatal alike. Autorotation practice is far and away the most common set-up for accidents on dual flights, making up more than 40 percent of the total, followed by various types of mechanical failures and unexplained power losses at a little under 20 percent. As in fixed-wing training, taking off and landing is the single most prevalent problem on student solos (no accidents were specifically attributed to go-around attempts), but the difference in scale is huge: These make up less than 30 percent of solo helicopter accidents versus 80 percent in airplanes. Student pilots were also more susceptible to losses of control while hovering, hover taxiing, and similar low-airspeed, low-altitude maneuvers, which account for about 20 percent of primary training accidents on solo and dual flights alike.
Since the entire report runs more than 10 times as long as this synopsis, plenty of interesting things remain for you to find. Advanced instruction, for example, is a catch-all category containing everything from VFR flight reviews to Part 135 standardization training. As far as we know, this report is the first to sort out which of these activities are relatively trouble-free and which involve risks that may be underappreciated. The next time bad weather leaves most of your CFIs sitting around looking bored, you could do worse than suggest they dig into our research. Their students would probably benefit from it, too.
Originally appeared in AOPA’s Flight School Business News online, June 30, 2014