A Beech 35-C33 (N5891J) was destroyed after impacting hilly, wooded terrain near Pulaski, Tennessee, at about 1103 local time on December 7, 2023. The private pilot and one passenger sustained fatal injuries. The flight was operated under Part 91 as a personal cross-country flight originating at Knoxville Downtown Island Airport (DKX), Knoxville, Tennessee, and destined for Saline County Regional Airport (SUZ), Benton, Arkansas.
According to air traffic control communications and ADS-B data, the airplane departed DKX about 0948 and initially climbed and turned to a ground track of about 255 degrees. The flight then leveled at about 2,500 ft mean sea level (msl) for approximately 12 minutes before climbing to 6,500 ft msl. Communications between the pilot and controllers during the departure and initial en route portion were described as normal.
After the climb toward 6,500 ft msl, recorded groundspeed decreased to about 80 knots before increasing to around 130 knots after reaching altitude. The airplane maintained about 6,500 ft with groundspeed just below 130 knots for about 10 minutes. After about 1020, ADS-B data showed the airplane began a series of descents to about 6,000 ft with associated increases in groundspeed, followed by climbs back to about 6,500 ft while slowing. Around this period, the flight was handed off to Memphis Center for the final portion of flight following services, and the controller issued the nearest altimeter setting and queried the airplane’s altitude; the pilot acknowledged and confirmed.
A performance study using ADS-B data indicated that by about 1033, altitude and speed fluctuations became more pronounced and the airplane no longer maintained a steady altitude for any significant amount of time. Weather conditions near the time of the accident indicated calibrated airspeed was about 5 knots lower than groundspeed. The data showed the airplane gaining airspeed while descending and slowing while climbing, with airspeed fluctuating between about 100 and 160 knots while repeatedly gaining and losing about 1,000 to 1,500 ft of altitude. Rates of climb varied between about -1,200 ft per minute during descents to near 500 ft per minute during climbs, with additional smaller altitude variations also observed.
About 1036, the airplane entered a descent that was arrested near 5,300 ft at an airspeed of about 133 knots, then climbed to its highest recorded altitude of about 7,000 ft msl before descending again. During this portion of the flight, the controller advised the pilot that the airplane was “well left of course.” The pilot acknowledged and stated that a correction was being made; however, flight track data showed the airplane remained significantly left of course. The airplane’s headings were described as relatively stable through most of the flight, despite the increasing altitude deviations.
After about 1059, the airplane slowed from about 160 knots to about 140 knots while level near 4,500 ft, then began a climb above 6,000 ft. During this climb, the airplane continued to slow. The controller attempted to contact the pilot twice to advise that the airplane needed to contact Memphis Center; no response was received. Shortly afterward, faint emergency radio calls were received, including a transmission from the pilot indicating an emergency, followed about 60 seconds later by a faint transmission from the passenger requesting help. Subsequent attempts to reach the airplane were unanswered, and no further communications were recorded.
ADS-B data indicated the emergency transmission coincided with a left turn and an increasing descent rate of about 2,000 ft per minute with airspeed increasing above 170 knots. During the final portion of the flight, the airplane entered a rapid, uncontrolled descent. In the last several seconds, the airplane was on a ground track of about 262 degrees while descending at an airspeed of about 230 knots, with a descent rate exceeding 10,000 ft per minute before radar contact was lost near the accident site.
The airplane impacted terrain at an elevation of about 971 ft, with the wreckage path oriented on a heading of about 268 degrees magnetic. The debris field extended about 100 yards and included evidence of tree strikes leading to the main impact area. Fuel tanks were breached consistent with impact damage, and an on-ground fire spread to surrounding vegetation. A witness reported the airplane flew overhead at a high rate of speed and stated the engine was running when the airplane impacted the ground.
Postaccident examination did not reveal evidence of anomalies or mechanical irregularities that would have precluded normal operation, though fragmentation and fire damage precluded a complete evaluation of the flight controls and autopilot system. Flight control continuity could not be established due to impact and fire damage; observed cable separations displayed features consistent with tensile overload. The cockpit was destroyed, and autopilot panel settings could not be determined due to damage. Two onboard video recording devices were recovered; one memory card was destroyed beyond repair and the other contained no recordings from the accident flight.
The airplane was equipped with a Century 2000 autopilot described as a prompting system without automatic elevator trim. When a TRIM prompt displayed, the pilot was required to manually move the trim in the indicated direction until the annunciation extinguished. The report stated that the airplane’s heading stability during the initial portion of the flight made it likely the autopilot was being used. Flight instructors who had flown with the pilot before the accident indicated the pilot demonstrated poor manual aircraft handling and struggled with cockpit automation, including autopilot and trim use. The pilot’s training history was described as showing difficulty maintaining situational awareness, and one instructor reported advising that the high-performance airplane the pilot purchased about 1.5 years before the accident was beyond the pilot’s proficiency.
Toxicology testing detected multiple medications in postmortem tissue specimens. The report stated the pilot may have been experiencing performance-impairing effects of medication use or an associated underlying condition at the time of the accident, and that such effects may have diminished the pilot’s ability to render effective control inputs. The report further stated that available medical and circumstantial evidence was insufficient to establish whether such effects contributed to the accident, particularly given the pilot’s demonstrated baseline proficiency in the airplane.
The stated probable cause was: “The pilot’s failure to maintain airplane control, which resulted in pilot-induced oscillations and a subsequent loss of control and impact with terrain.” Findings listed were “Aircraft control – Pilot” and “Pitch control – Not attained/maintained.”
