Accident Analysis: Setting a bad example

A glaring example occurred in December 2012. After the third landing on a four-leg cross-country in a piston helicopter, the student—who owned the aircraft—expressed concern about the low quantity showing on the fuel gauge. His instructor replied that “the fuel gauges were often faulty” and that “we have enough to make the last leg of the flight.” By his own account, the CFI interpreted a three-eighths reading on the gauge to mean they had 15 gallons (of the original 40) left, and calculated that “with fuel burn at 13.5 gallons per hour and 30 to 35 minutes to [the destination], we should land with the required 20-minute reserve.”

Let’s pause here to think about the lesson he might have taught and what he did instead. Rather than addressing a reasonable doubt about their fuel supply by stopping to make certain they had enough to get home, the instructor waved it off, relying on a gauge he’d already described as “faulty” and an assumption that he knew their exact fuel burn to conclude that they “should” land with the bare minimum reserve required by law. Not would, “should.” How’s that for an example of lax flight planning and aeronautical decision making?

Rather than addressing a reasonable doubt about their fuel supply, the instructor waved it off, relying on a gauge he’d already described as “faulty.”This would be hard enough to condone if they’d made it safely back to base, but they didn’t. As they approached the field the helicopter yawed left—the classic symptom of a loss of engine power—and both the engine rpm and main rotor rpm began decreasing. The instructor took the controls but couldn’t prevent the main rotor rpm from decaying below redline (the equivalent of stalling an airplane during an engine-out approach), and the helicopter landed hard. Neither man was injured, but the main rotor severed the tail boom, wrecking the helicopter.

The engine ran smoothly once fuel was supplied. The instructor claimed that the sprag clutch—the device that’s supposed to disengage the main rotor in the event of an engine failure—had malfunctioned, but investigators found it in good working order. Whether you buy the CFI’s story or think he mishandled the emergency autorotation, there’s no doubt the emergency was one of his own creation. If there’s a silver lining beyond the avoidance of injury, it’s that at least the student didn’t come away believing this was an appropriate way to manage a flight. Future students were also given a fine example of when and why to challenge a CFI, while future instructors got an equally outstanding example of how not to teach.

Working for the AOPA Air Safety Institute gives statistician David Jack Kenny even more incentive to avoid embarrassing lapses in judgment.