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Fast and looseFast and loose

By David Jack Kenny

Appearances notwithstanding, aerobatics are not particularly dangerous—when flown at suitable altitudes in appropriate aircraft by adequately trained pilots. Recent years have averaged fewer than a dozen accidents during aerobatic practice or competitions, though when they have occurred they’ve tended to be severe: 85 percent resulted in fatalities. By definition, operating near the edge of the flight envelope reduces the margin for error, making it especially crucial that both aircraft and pilot be in top condition.

The Extra EA-300 that crashed near Salinas, Calif., on Easter Sunday 2012 was unquestionably an appropriate aerobatic aircraft. With a symmetric airfoil set at zero angle of incidence, a 300-horsepower Lycoming AEIO-540 engine with inverted fuel and oil systems, and an airframe rated for plus or minus 10 Gs, it’s a model that’s regularly flown in Unlimited-category competition. The owner of the shop that had recently re-rigged the flight controls and overhauled the engine, herself a competitive aerobatic pilot, said that this particular example was “flying great” throughout a series of evaluation flights that included “tumbles, spins, and accelerated spins,” Immelmanns, and split-Ss.

The man at the controls would also have to be considered well qualified. He was an active-duty Marine Corps fighter pilot assigned to fly the AV-8B Harrier. His logbook showed about 90 hours of civilian flight time in addition to nearly 400 hours of military experience, and he was a co-owner of the EA-300. He’d brought a passenger along for the ride, a 200-hour private pilot with no known aerobatic experience.

Altitude, however, was not abundant. Two witnesses saw the airplane maneuvering between 1,000 and 2,000 feet agl. One, a commercial pilot with “limited” experience in aerobatics, saw it perform two chandelles parallel to the foothills, and then turn south toward the valley. It did two fast aileron rolls and started a third, only to pitch down abruptly while inverted. After descending “four airplane widths,” it briefly pitched back up, rolled to 90 degrees of bank, and then returned to the inverted attitude. The nose dropped again and this time continued dropping until the airplane hit the ground in a near-vertical descent; the engine noise remained constant throughout. Both men on board were killed.

Examination of the wreckage found no anomalies with the engine beyond impact damage. All three propeller blades were shattered, indicating that the engine was producing power. The push-pull tubes controlling the elevator and ailerons were buckled and broken in multiple places, all consistent with overload fractures; the rudder cables had been cut by first responders but were otherwise intact.

In the tail cone, however, investigators found a loose XM weather satellite antenna. Its cable had gotten wrapped around the elevator bellcrank, and one section of the cable had “abrasions, cuts, and twist deformations.” The antenna itself, a disk about the size and shape of a hockey puck, showed scrapes and cuts that matched witness marks on the bellcrank—and a 9-mm gouge that conformed precisely to the end of a 9-mm bolt securing the forward spar of the vertical stabilizer to the fuselage frame. The portable GPS unit to which the antenna would have been connected wasn’t found in the wreckage, but Sirius-XM confirmed that the pilot had taken out a weather datalink subscription 10 days before the accident.

Investigators concluded that in the course of the earlier maneuvers, the unsecured antenna had migrated into the tail cone and gotten wedged between the elevator bellcrank and the spar, effectively jamming the elevator as the airplane rolled inverted. Low altitude meant little time to experiment with freeing the elevator by moving the stick or look for other ways to recover control. Radar track data showed that less than a minute elapsed from the last heading change—presumably just before the first roll—and the last data point, recorded after the Extra had dropped below 1,300 feet.

Experienced aerobatic pilots are militant about making sure there are no loose items anywhere in the aircraft, and stray hardware isn’t just a hazard to aerobatic flight: The fatal 2010 crash of a Tecnam P2002 Sierra was linked to a mechanic’s work light found jammed under the stabilator control tube in the tail cone. In that case, too, the airplane was maneuvering fairly low just before the accident. There’s no certainty that more altitude would have enabled either pilot to recover, but it couldn’t have hurt: Altitude is time, especially in unusual attitudes, and there’s no reason the Extra’s pilot couldn’t have given himself a little more of both. Archived metars from the Salinas airport show the skies were clear all morning.