History of Flight
On February 27, 2017, at approximately 0741 mountain standard time, a Cessna 172S airplane, registration N2461N, collided with Culver Reservoir near Berthoud, Colorado. The flight instructor and the pilot receiving instruction sustained fatal injuries, and the airplane was substantially damaged. The operator, McAir Aviation, LLC, conducted the flight under 14 CFR Part 91. Day visual meteorological conditions prevailed for the local instructional flight, which departed Rocky Mountain Metropolitan Airport at 0724.
The purpose of the flight was for the pilot receiving instruction to demonstrate spin entry and recovery as part of his training for a flight instructor certificate. Radar data showed the airplane climbed northward, then performed maneuvers including a rapid descent and climb. At 0740:35, about one mile south of Culver Reservoir, the airplane turned right and slowed below 40 knots. Between 0741:03 and 0741:40, it descended from 10,800 to 6,800 feet msl, averaging a descent rate of 6,500 feet per minute. The last radar point was at 6,800 feet msl, about 1,700 feet above ground.
Two witnesses reported hearing a reduction in engine power and seeing the airplane in a nose-down spin. One witness observed about five turns before the airplane descended below a tree line, and the other heard a sound consistent with impact. Neither witness saw the airplane hit the reservoir.
Personnel Information
The 58-year-old flight instructor held a commercial pilot certificate with single-engine and instrument ratings, and a flight instructor certificate with similar ratings. His last medical examination was on June 24, 2016, with a limitation for near-vision glasses. He was employed as chief pilot and had 6,678.5 total flight hours.
The 23-year-old pilot receiving instruction held a commercial pilot certificate issued on August 31, 2016. His last medical examination was on January 6, 2015, with no limitations. According to his father, he had about 550 hours of flight experience, with about 400 hours flown in the previous year.
Aircraft Information
The 2005 Cessna 172S, serial number 172S10043, was a high-wing monoplane with a Lycoming IO-360-L2A engine (180 hp) and a fixed-pitch McCauley propeller. The airframe had 4,703 hours total time; the engine had 5,994.6 hours since new and 1,862 hours since overhaul. The airplane had a certified maximum gross weight of 2,550 pounds and was approved for spins in the utility category. Maintenance records showed no unresolved issues. The airplane departed with 27 gallons of fuel, and the weight and balance was within utility category limits.
Meteorological Information
Day visual meteorological conditions prevailed. The nearest reporting station, Fort Collins-Loveland Municipal Airport, about 15 miles away, reported at 0756: wind 050° at 5 knots, 10 miles visibility, clear sky, temperature -7°C, dew point -9°C, altimeter 29.68 inHg.
Wreckage and Impact Information
The wreckage was found partially submerged in Culver Reservoir at 5,142 feet msl. All major components were intact; the right wing leading edge was crushed upward and aft 45°, the left wing leading edge crushed flat. The engine was compressed up and aft into the firewall. Flight control continuity was established, with aileron cables disconnected for recovery. Flaps were fully retracted. No mechanical malfunctions or failures were found that would have precluded normal operation.
The engine examination revealed continuity, compression on all cylinders, and normal spark plug appearance. No anomalies were found with the fuel system or propeller. The propeller blades showed no chordwise scoring.
Medical and Pathological Information
Autopsies attributed both fatalities to multiple blunt-force injuries. Toxicological testing for the flight instructor was negative for carbon monoxide, ethanol, and drugs. The pilot receiving instruction tested positive for dextromethorphan, dextrorphan, doxylamine, and ibuprofen in urine; blood levels of dextromethorphan, dextrorphan, and doxylamine were too low to quantify. Acetaminophen (35.75 µg/ml) was found in urine. These substances are not considered impairing at typical doses.
Tests and Research
The airplane was equipped with a Garmin G1000 avionics suite, but no memory card was installed to record flight parameters. An Apple iPad Air, iPad Air 2, and iPhone 5S were recovered; forensic examination of the iPad Air failed, the iPad Air 2 was password-protected, and the iPhone 5S yielded only photos and an encrypted backup, neither of which were pertinent.