The crash of an air ambulance in Manchester last year that killed three crew members probably happened because the pilot became disoriented after unexpectedly flying into fog, a federal agency has determined.
The pilot likely made a maneuver that placed too much stress on the helicopter, which broke apart in flight, according to interviews and the report from the National Transportation Safety Board.
The June 6 crash of the Air Evac Lifeteam flight killed pilot Eddy Sizemore, 61, who had been a longtime Laurel County sheriff's deputy; flight paramedic Herman "Lee" Dobbs, 40, of London; and flight nurse Jesse Jones, 28, of Pineville.
The crew members had taken a patient to St. Joseph Hospital in London and were returning to their base in Manchester when the helicopter crashed in a school parking lot about 750 feet from the helipad.
At two seconds after 11:15 p.m., the Air Evac control center recorded someone on the helicopter saying "no" and then nothing more.
The forecast was for weather conditions that would be clear enough for visual flight, but witnesses reported patches of fog had developed around the time of the crash, according to the NTSB report.
An updated forecast issued 10 minutes before the crash indicated fog or low clouds could develop, but Sizemore and his crew were in the air at that point.
It is likely the helicopter encountered conditions that called for flying by instrument, which caused Sizemore to become disoriented, the report said.
With visual cues such as the ground or horizon obscured at night, the motion-sensing function of the inner ear can confuse a pilot, creating a "very compelling" illusion that an aircraft is turning when it isn't, the NTSB report said.
One of those so-called "vestibular illusions" is called the graveyard spiral.
A witness reported seeing the helicopter flying lower than normal and spinning before the crash, according to the report.
Data showed the helicopter descending in three right circuits near the landing pad. The flight path was consistent with an effort to avoid fog followed by a loss of control, the NTSB concluded.
Seth Myers, president of Missouri-based Air Evac Lifeteam, said if a pilot makes certain maneuvers because he or she feels the aircraft is turned the wrong way, it can place enough stress on the craft to cause it to break apart.
The wreckage of the helicopter Sizemore was flying, a Bell 206 L-1, showed the main rotor and tail boom separated from the cabin in the air, according to the NTSB.
The main rotor was 300 feet from the spot where the cabin hit and burst into flame, and the tail boom was in a separate spot 300 feet from the point of impact, the report said.
The NTSB looked at other possible causes of the crash, such as mechanical problems or impact with a power line, but said the probable cause was spatial disorientation.
The agency documents facts about air crashes and decides on the most likely cause. It issued its probable-cause findings on the helicopter crash this week.
Myers noted that Sizemore had thousands of hours of experience, and that patches of fog or low clouds were not predicted at the time of the crash.
Air Evac uses a point system to evaluate those risks. The flight that night was rated low risk, according to the NTSB.
"His judgment is not in question," Myers said of Sizemore. "This was an unfortunate situation that Eddy found himself in. You have seconds to make decisions."