ACCIDENT RECOVERY By David Jack Kenny
Too Much Fun Did a pilot’s search for adventure lead to tragedy instead?
A
VIATION IS EXHILARATING. The career paths that make up the industry’s pilot pipeline couldn’t be sustained if it weren’t. The steep
expense of initial training, the long hours and low pay of flight instruction, the tedium and hazards of pipeline patrol, air tours, and offshore shuttles are all made toler- able by the innate joy of flight. If pilots occasionally indulge in the taste for the thrills that originally attracted them to flight training, well, that’s only human nature. Of course, most of what’s considered safety culture consists of thwarting human nature, or at least restrict- ing its scope for circumventing the rational mind’s efforts at risk assessment and mitigation. That’s the reasoning behind standard operating procedures that remove as many decisions as possible from the individuals who actually operate the aircraft.
The Flight N74137 was an Airbus AS350 B3 air ambulance operat- ing from Air Methods’ local base in Globe, Arizona. Early in the afternoon of December 15, 2015, it was dis- patched to transport a cardiac patient from Globe to Mesa. The flight was crewed by a pilot, flight nurse, and flight paramedic. Conditions were characteristic of the Phoenix area in December: clear skies, light northwest winds, and essentially unlimited visibility. The flight was short, about 25 minutes, and the patient remained stable throughout. After unloading him, the helicopter refueled at Phoenix-Mesa Gateway Airport (KIWA) before departing for home. Data recovered from the aircraft’s onboard Appareo
GAU2000 data logger, which obtained position and alti- tude data from its own internal GPS and airspeed and altitude readings from the helicopter’s pitot-static sys- tem, showed the helicopter initially traversing the area around Gold Canyon at about 500 feet above ground level (agl). As it approached the Superstition Mountains heading east-northeasterly, it climbed enough to begin skimming over the hills at altitudes ranging from more than 1,000 feet above the valley floors to as little as 240 feet above the peaks.
During the last three minutes of the flight it flew even lower, remaining below 800 feet agl and crossing
ridgelines with less than 50 feet to spare. After travers- ing the rim of Rogers Canyon just 30 feet above a sad- dle, the ship descended and accelerated, following the canyon floor. Ground speed reached 148 knots at an alti- tude of no more than 300 feet agl as the helicopter tracked toward the next ridge. The flight paramedic later recalled hearing the pilot say, “Oh, shit” and seeing him making “jerky fast hand move- ments” on the controls. After a hard right bank the para- medic likened to “try[ing] to do a U-turn at 60 miles an hour,” the aircraft hit the next ridgeline just below another saddle point at an altitude of 5,035 feet. It was 5:23 p.m.
Most of what’s considered safety culture consists of thwarting human nature.
The Pilot The 51-year-old commercial pilot had logged 5,670 hours in a 25-year flying career. He was the Globe base’s safety officer, a role that the paramedic said he “took very seriously.” The pilot was well liked by his team- mates, in part because of his willingness to help clean the aircraft and equipment after transports. The para- medic also described him as liking to fly lower than their other pilots, but “not like dangerously low or anything.” The paramedic also mentioned the pilot’s service in
the US Army, as did other flight crew at the Globe base. It would appear, however, that he didn’t fly for the army. His résumé cited no military flight experience, and the file assembled during the National Transportation Safety Board (NTSB) investigation includes his honorable dis- charge with the explanation “Failure to qualify for flight training – no disability.” His civilian medical certificate required the use of corrective lenses.
The Flight Controls The NTSB’s report makes particular note of the phenom- enon of servo transparency, a condition in which the aerodynamic loads generated by the main rotor system exceed the forces produced by the aircraft’s hydraulic system. The difference “is transmitted back through the pilot’s collective and cyclic controls” and increases
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