History of Flight
On December 12, 2021, at approximately 0931 central standard time, a Cessna 310J airplane, registration N3187L, was destroyed in an accident near Inola, Oklahoma. The pilot sustained fatal injuries. The flight was conducted as a Title 14 Code of Federal Regulations Part 91 ferry flight.
The owner of the airplane, who had purchased it in March 2020, became ill and was unable to fly it. In March 2021, he requested a maintenance company at Tulsa International Airport (TUL) to perform the required annual inspection. A short maintenance test flight was conducted, which was the first flight since March 2020. The maintenance company found several discrepancies, including airframe corrosion and a recommendation to overhaul both engines, and refused to complete the annual inspection until those issues were resolved. Months later, the owner hired the accident pilot—a mechanic who had previously worked on the airplane—to ferry it to North Carolina for the overdue annual inspection.
Before departure, the fuel tanks were topped off, and the pilot performed a preflight inspection that lasted about an hour. After starting the engines and taxiing, the owner, monitoring air traffic control (ATC) communications on a handheld radio, heard the pilot report an engine issue and request to return to the ramp. The pilot called the owner, then performed an extended engine run-up. Approximately 20 minutes later, the pilot taxied back for departure.
ATC and Flight Track
ATC communications show that at 0838, the pilot requested a VFR clearance. At 0855, he reported needing to taxi back due to a "miss on the right engine there pretty bad." About 20 minutes later, he stated he was ready to try again. At 0921, he was cleared for takeoff with instructions to turn left to a heading of 090°. At 0925, he acknowledged a climb to 9,500 ft mean sea level. At 0932:36, the tower controller terminated radar services and approved a frequency change; the pilot did not respond.
ADS-B data from 0922 to 0931:11 shows the airplane climbing to 5,800 ft msl. About one minute before the accident, it turned left to the north and began a rapid descent. During the last 23 seconds, the descent rate increased from about 1,000 to 30,000 ft per minute, ground speed varied between 151 and 198 knots, and heading varied between 027° and 007°.
Wreckage and Impact
The wreckage was located at about 1100 on a private ranch by cattle-tending personnel; there were no witnesses. The impact crater indicated a magnetic heading of about 060°, and the debris field was about 900 ft long. Fragmented wing, tail, and control surfaces were found first. Two large craters consistent with the left and right engine/propeller assemblies were located about 300 ft apart. The main wreckage—inboard wings, nacelles, fuselage, and cockpit—was about 300 ft from the right engine crater.
The landing gear was retracted. Cockpit instruments were destroyed. The throttle quadrant showed left and right throttles full forward; left propeller at feather; right propeller full forward; mixtures full forward. The empennage separated; vertical stabilizer and most of the rudder remained attached; horizontal stabilizer and elevators separated and fractured. Structural deformation was noted without signs of corrosion or pre-existing cracking. Due to impact damage, flight controls could not be functionally examined.
Both engines were disassembled. The left engine would not rotate; metallic deposits were found in oil components but their origin could not be determined. The right engine rotated with continuity to all pistons and accessory gears. Magnetos were damaged and untestable. Propeller assemblies showed no pre-impact failure or malfunction; both had indications consistent with low power and blade positions near feather angles at impact.
ATC Review
A review of TUL radar replay (STARS) showed that during the last 30 seconds of flight, the airplane's altitude dropped from 6,100 ft msl to 4,700 ft, then displayed rapidly changing data. At 0931:21, the track went into coast status. About 30 seconds later, the track became inactive (ZZ). The controller terminated radar services at 0932:36 and called the pilot without response.
The replay also revealed a VFR airplane at Claremore Regional Airport (GCM) about 5 nautical miles north of the last ADS-B target. The controller, after the track went to ZZ, used a quick look function that displayed ADS-B codes and call signs. The VFR airplane was not the accident aircraft, and no other aircraft were near the accident airplane's last location. The controller pressed the "beacon all" button ten times. No alert notice was issued.
Pilot and Aircraft Information
The pilot's logbook was not found; his recent flight review and total time in the accident airplane could not be determined. A work order from the maintenance company that began the annual inspection in March 2021 listed a discrepancy: "Left hand Prop control will not feather." The work order also stated, "Inspection stopped. Aircraft unairworthy. Aircraft put back together for customer."
Toxicology
Toxicology testing by the FAA's Forensic Sciences Laboratory identified gabapentin in urine and liver tissue. Gabapentin is an antiseizure medication also used for nerve pain, with warnings about sleepiness and dizziness. The FAA considers gabapentin disqualifying for a medical certificate.