N5891J – BEECH 35-C33 – 2023-12-07 NTSB Accident Report

HISTORY OF FLIGHTOn December 7, 2023, at 1103 central standard time, a Beech 35-C33 airplane, N5891J, was destroyed when it was involved in an accident near Pulaski, Tennessee. The private pilot and passenger sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The flight originated from Knoxville Downtown Island Airport (DKX), Knoxville, Tennessee, about 0948 and was enroute to Saline County Regional Airport (SUZ), Benton, Arkansas, which was about 430 nm away. Air traffic control communications and ADS-B data provided by the FAA revealed that after takeoff from DKX, the airplane climbed and turned to a ground track of 255°, then leveled off for about 12 minutes at 2,500 ft mean sea level (msl), before climbing to 6,500 ft msl. Controller and pilot communications during the departure and up to the initial enroute portion of the flight were normal.

The airplane’s headings remained relatively stable throughout most of the flight; however, shortly before leveling off at 6,500 ft msl, the airplane’s groundspeed dropped to 80 kts before accelerating to 130 kts once reaching altitude. The airplane maintained 6,500 ft and a groundspeed just below 130 kts for about 10 minutes. After 1020, the airplane began a series of descents to 6,000 ft, along with an associated increase in groundspeed, before climbing back to 6,500 ft while slowing; it was about this time when the controller handed off the pilot to the Memphis air route traffic control center (ARTCC), who provided services during the final portion of the accident flight. The controller issued the nearest altimeter setting and questioned the pilot’s altitude, which the pilot acknowledged and confirmed.

An aircraft performance study was conducted with ADS-B data, and the Beechcraft Debonair 35-C33 and Bonanza E33 F33 Pilot’s Operating Handbook and FAA Approved Airplane Flight Manual. The study indicated that, at 1033, the altitude and speed fluctuations became more pronounced and that the airplane no longer maintained a steady altitude for any significant amount of time. Weather conditions from the time of the accident indicated that the calibrated airspeed was about 5 kts lower than the groundspeed (figure 1). The airplane gained airspeed while descending and slowed while climbing. Airspeed fluctuated between 100 and 160 kts while repeatedly gaining and losing 1,000 to 1,500 ft of altitude.

The rate of climb varied between -1,200 ft/min during the descents to near 500 ft/min during the climbs. Smaller variations in altitude during the climbs and descents were also observed.

Figure 1. Airplane altitude, calculated airspeed, and groundspeed for the final 40 minutes of flight.

About 1036, the airplane entered a descent that was arrested about 5,300 ft at an airspeed of 133 kts, after which it climbed to its highest altitude of about 7,000 ft msl before descending again. The controller informed the pilot that she was “well left of course” and the pilot acknowledged and responded that she was correcting. However, the correction was small, and flight track data indicate that she remained significantly left of course.

After 1059 the airplane slowed from 160 kts to 140 kts while remaining level about 4,500 ft before beginning a climb to above 6,000 ft. During the climb, the airplane continued to slow. The controller twice attempted to contact the pilot in order to advise that she needed to contact the Memphis center control, but no response was received.

About 1103, there was a faint communication received from the pilot stating the “…this is Debonair, [unintelligible…] Emergency.” The transmission coincided with the airplane turning left, with a corresponding descent rate of about 2,000 ft/min and the airspeed increasing to over 170 kts (see figure 2). About 60 seconds later, a faint male voice transmitted, “[unintelligible], oh…. help us.” The controller’s subsequent attempts to contact the pilot were unanswered, and there was no further communication from either the pilot or passenger. During this time, the airplane was in a rapid descent before radar contact was lost in the vicinity of the accident site. During the last several seconds of the flight, the airplane was on a ground track of 262° descending at an airspeed of 230 kts, and the descent rate was over 10,000 ft per minute.

Figure 2. Airplane altitude and track, with calculated airspeed and groundspeed and selected ATC communications, at the end of the flight. PERSONNEL INFORMATIONOn October 20, 2021, the pilot passed her Private Pilot Airplane Airmen Knowledge Test. On May 14, 2022, she passed her private pilot (single-engine land) practical test, at which time she had accumulated 193.2 hours total flight time. Of those hours, 182.6 were dual instruction received; nearly all of the hours were accomplished in a Piper PA-28-140 that she had purchased on June 15, 2021. The following year she sold PA-28-140 and subsequently bought the accident airplane on July 13, 2022. The pilot’s logbook was found at the accident site but was heavily damaged. The most recent logbook pages that were not damaged revealed the pilot had logged 390.3 hours total time as of August 14, 2023, about 3 months and 3 weeks before the accident flight. None of the pilot’s logbook endorsements were contained within the undamaged segment of logbook that was reviewed.

An interview with one of the pilot’s former flight instructors was conducted. The instructor stated that she, “leaned on technology too much and did not have solid stick and rudder flying skills.” Regarding the systems on the airplane, specifically the trim and autopilot, he stated that she would often confuse the trim direction and would manually adjust the trim in the wrong direction. The instructor stated, “For instance, she could get flustered. If that trim was in the wrong position, if the autopilot was not happy, she would just disconnect it and fly manually.” On the autopilot, “She would press the Down or Up button repeatedly. I would just tell her to gently press and hold the button down,” she would “repeatedly” push it.

A subsequent interview with the general manager of the pilot’s flight school indicated that her training progress was not meeting the necessary proficiency levels. He reported that several weeks before the accident she was given an instrument phase check and that it did not go well on almost all aspects of aircraft control, situational awareness, and risk management. He reported that he advised her that she was behind the Debonair and that he believed she had purchased more aircraft than she was ready for. “She and her father did not disagree when I repeated this assessment.” AIRCRAFT INFORMATIONThe airplane was equipped with a Continental IO-470-N six-cylinder, fuel-injected engine producing 260 horsepower. The airplane featured retractable landing gear and a constant-speed propeller, making it a complex and high-performance airplane. These systems require specific pilot management and add to the aircraft's complexity compared to fixed-landing gear, fixed-pitch propeller trainer airplanes. It was capable of a maximum structural cruising speed of 161 knots and had a never-exceed speed of 195 knots.

The airplane was equipped with a Century 2000 autopilot. This model was a prompting autopilot, meaning automatic control of the elevator trim (auto trim) was not available on this system. When the autopilot displayed a flashing TRIM UP or TRIM DOWN on the annunciator, the pilot would need to manually move the trim control of the airplane in the direction indicated on the autopilot. When the autopilot determined that the trim condition was satisfied, the trim lamp on the annunciator would extinguish and the pilot could then stop trim action. There were 2 degrees of trim prompting: for a small trim error, the trim prompt will flash approximately once each second. A large trim error will cause the prompt to flash approximately 3 times per second. A large error not corrected for a period of approximately 2 minutes would sound an alert for 5 seconds. The alert would repeat every 2 minutes until the error was corrected.

According to airworthiness records, the pilot’s previous airplane, the Piper PA-28-140, had fixed landing gear, a fixed-pitch propeller, and a 160-hp engine installed in accordance with a supplemental type certificate; it was not a high performance or complex airplane. FAA airworthiness records showed that the airplane had been equipped with a Bendix King/Tru Trac autopilot system. Its cruise speed was about 110 kts with a maximum speed of 125 kts. AIRPORT INFORMATIONThe airplane was equipped with a Continental IO-470-N six-cylinder, fuel-injected engine producing 260 horsepower. The airplane featured retractable landing gear and a constant-speed propeller, making it a complex and high-performance airplane. These systems require specific pilot management and add to the aircraft's complexity compared to fixed-landing gear, fixed-pitch propeller trainer airplanes. It was capable of a maximum structural cruising speed of 161 knots and had a never-exceed speed of 195 knots.

The airplane was equipped with a Century 2000 autopilot. This model was a prompting autopilot, meaning automatic control of the elevator trim (auto trim) was not available on this system. When the autopilot displayed a flashing TRIM UP or TRIM DOWN on the annunciator, the pilot would need to manually move the trim control of the airplane in the direction indicated on the autopilot. When the autopilot determined that the trim condition was satisfied, the trim lamp on the annunciator would extinguish and the pilot could then stop trim action. There were 2 degrees of trim prompting: for a small trim error, the trim prompt will flash approximately once each second. A large trim error will cause the prompt to flash approximately 3 times per second. A large error not corrected for a period of approximately 2 minutes woul...