History of Flight
On April 21, 2012, at about 1220 eastern daylight time, a Cirrus Design Corp SR22 (registration N110EB, serial number 3423) was substantially damaged when it impacted heavily wooded terrain near Newcomerstown, Ohio. The private pilot, the sole occupant, sustained fatal injuries. Instrument meteorological conditions prevailed and an instrument flight rules flight plan was filed. The flight operated under 14 CFR Part 91 as a personal cross-country flight, originating from Somerset Airport (SMQ) at 1013 and intended to terminate at Ohio State University Airport (OSU), Columbus, Ohio.
Radar data showed the airplane in cruise at 8,000 feet mean sea level at 156 knots ground speed. About five minutes before impact, Indianapolis ARTCC updated the altimeter setting; the pilot acknowledged normally. No further transmissions were received. The airplane then entered a descending right turn, with airspeed increasing slightly then dropping to 61 knots as the turn radius decreased. After turning about 270 degrees and descending to 4,900 feet, radar contact was lost. A boy in a passing car reported seeing the airplane emerge from low clouds in a descent, approximately wings level, before disappearing behind trees; he then observed black smoke.
Data from the on-board Recoverable Data Module (RDM) indicated anomalies in electrical bus voltages, autopilot mode changes, a momentary dropout of the pilot transmit frequency, and a descending right turn with decreasing radius until impact.
Personnel Information
The pilot held a private pilot certificate with Airplane Single Engine Land and Instrument Airplane ratings, and a valid third-class medical certificate issued April 28, 2010. At his most recent medical exam, he reported about 1,200 total flight hours, with 100 in the preceding six months. He completed a Cirrus Standard Perspective Differences and Cirrus Turbo Differences Course on April 14, 2009, and a Cirrus Icing Awareness Course on October 5, 2009. A flight instructor who flew with the pilot about once a month reported that the pilot completed a successful biennial flight review in the SR22 on February 17, 2012. Remnants of the pilot's logbook were found but were too damaged to read.
Aircraft Information
The Cirrus SR22 (serial number 3423) received its standard airworthiness certificate on April 13, 2009. Records indicated the pilot purchased the airplane new and took delivery on that date. The airplane was equipped with Garmin Perspective avionics (including dual AHRS and single air data computer), Chartview, GFC 700 autopilot with yaw dampener, Enhanced Vision System, Synthetic Vision, air conditioning, a Tornado Alley turbocharging system, supplemental oxygen, engine monitoring, traffic alerting system, TAWS-B, XM weather/radio, FIKI, a Tanis heater, and a recoverable data module. The electrical system featured two alternators and two batteries providing 28-volt DC power with automatic switching to the Essential Bus in case of failure. The flight instructor noted that the autopilot had disengaged once during a flight in fall 2011, possibly related to a battery issue.
Meteorological Information
The closest weather reporting station was Zanesville Municipal Airport, 24 miles southwest. At the accident time, an un-augmented ASOS reported wind from 340° at 5 knots, visibility 7 miles in light rain, ceiling broken at 800 feet agl, overcast at 1,200 feet, temperature 6°C, dew point 4°C, altimeter 29.89 inches Hg. Remarks indicated ceiling variable 600 to 1,000 feet and hourly precipitation 0.01 inch.
Wreckage and Impact
The main wreckage was located on a heavily wooded hillside at 40°14'58.32"N, 81°32'44.95"W, elevation about 1,060 feet msl. The energy direction was about 093° magnetic, with a 10° upslope. Initial impact involved two trees about 31 feet apart, with scars at heights of 44 and 34 feet. A crater 3–4 feet deep and 11 feet long contained the propeller hub and a portion of the crankshaft. The main wreckage (firewall, engine, instrument panel, center console) rested against trees at the crater's far end. The aircraft was severely fragmented over a debris field roughly 370 feet long and 250 feet wide. Spot fires and fuel-damaged vegetation were observed. The impact angle was approximately 25–30° nose down with wings level.
Engine examination revealed extensive impact damage but no pre-impact anomalies in magnetos, spark plugs, fuel pump, or cylinders. All three composite propeller blades were fractured near the hub. The left front seat airbag deployed; the right front seat airbag was also deployed. The Cirrus Airframe Parachute System (CAPS) safety pin was found, and evidence indicated the system was not deployed before impact. The activation cable was fractured with tension overload appearance. The rocket motor igniter base showed residue consistent with ignition, but the parachute remained in its D-bag with only partial extraction of suspension lines.
Medical and Pathological Information
An autopsy of the pilot found no medical issues that could have contributed to the accident. Toxicology tests were negative.
TESTS AND RESEARCH
RDM data showed that before the upset, the airplane was at 8,000 feet pressure altitude, 148 knots, heading 273° magnetic on autopilot in GPS lateral and ALT vertical modes. At 16:18:30 UTC, Alternator 2 current data became invalid, and Battery 1 current briefly became invalid then changed to -27 amps. Bus voltages dropped from 28–29 to 23–25 volts. Three seconds later, the autopilot disengaged to flight director only, and the airplane began rolling right. About 13 seconds later, pitch decreased and altitude dropped. At 16:18:53, the autopilot re-engaged in ROLL and PITCH modes with 32° right roll and 5° nose down. These attitudes increased to 63° right wing down and 24° nose down before reducing. When roll reached 48° and pitch 16° nose down at 203 knots, the autopilot mode changed to LEVEL at 16:19:09. Engine power was reduced five seconds later. Pitch attitude gradually returned to level by 16:19:27, while roll oscillated between 30° and 41° right wing down. The airplane then rolled sharply to 155° right roll and pitched down to 71° nose down, airspeed reaching 277 knots. Roll and pitch then reversed toward level, reaching 18° right wing down and 46° nose down when data ended at 16:19:47. Normal acceleration reached the recorded limit of 5 positive G's.
Testing on an exemplar airplane with the same software showed that cycling the avionics switch off caused the pilot transmit frequency to change from the selected frequency to a null value in the RDM data, similar to the anomaly observed in the accident flight.
Probable Cause
No probable cause was determined.