The National Transportation Safety Board has cited a loss of aircraft control possibly attributed to the misuse of the autopilot as one of the causal factors in the crash of a Beechcraft Debonair that killed aviation vlogger Jenny Blalock and her father James in December 2023 near Pulaski, Tennessee.
Blalock, 45, began her aviation training in 2021 and used video cameras in the cockpit to document her experiences on her YouTube channel, TNFlygirl.
The NTSB report released Friday noted cameras were not in use during the accident flight on December 7, 2023. The other videos were removed from the channel shortly after the accident.
Blalock did her primary training in a Piper Cherokee, then after earning her private pilot certificate in May of 2022, purchased a 1965 Beechcraft 35-C33 Debonair equipped with a 260 hp Continental IO-470 engine, making it a high-performance aircraft. It also had an autopilot, which, based on several of Blalock’s videos, she was having difficulty using.
In a few of the videos she wondered aloud if it was working correctly, and she made references to why it was turning the airplane or accidentally turning it off during a flight while she attempted to use her iPad to navigate in VFR conditions.
The 99-page NTSB report contains interviews with flight instructors who had flown with Blalock and commented on her lack of situational awareness and difficulty staying ahead of the airplane, specifically noting that she “demonstrated poor manual aircraft handling and struggled with cockpit automation, including autopilot and trim use” and sometimes got behind on the radio.
Two weeks before the accident, Blalock, who was in training for instrument certification, underwent a phase check and did not do well, according to the check instructor who in the NTSB report noted deficiencies 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, saying “She and her father did not disagree when I repeated this assessment.”
One of her former flight instructors stated that she “leaned on technology too much and did not have solid stick-and-rudder flying skills.” The instructor added that she would often confuse the trim direction and would manually adjust the trim in the wrong direction, saying, “… 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.”
The Debonair 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,” the NTSB report stated. “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 two minutes would sound an alert for five seconds. The alert would repeat every two minutes until the error was corrected.”
According to an instructor, when using the autopilot, she would press the down or up button repeatedly despite instructions to gently press and hold the button down.
One CFI told investigators that “she rarely knew where she was in relation to her navigation. It was a complex, high-performance airplane with a technical avionics package, with which she was not truly familiar.”
Accident Flight
On the morning of December 7, Blalock and her father waited for the weather to improve then launched in VFR conditions from Knoxville, Tennessee, with intentions of flying to Saline County Regional Airport (KSUZ) in Benton, Arkansas, a distance of approximately 430 nm, so the aircraft could have some avionics work performed.
The NTSB report notes the initial aircraft headings and controller-pilot communications were unremarkable. However, as the airplane reached its cruising altitude of 6,500 feet its airspeed and altitude began to fluctuate with it climbing up and down. The oscillations became increasingly more severe over about 25 minutes, with altitude deviations up to 1,500 feet and significant fluctuations in airspeed.
This ultimately developed into a steep and rapid nose-down descent of more than 10,000 fpm. There was a faint distress call, then contact was lost.
A witness in the vicinity of the accident site told the NTSB that the airplane flew overhead at a high rate of speed while the engine was running when it impacted the tops of several trees then the ground. The fragmented wreckage was found in hilly wooded terrain a short time later. The debris field was described as fan shaped and 100 yards long.
“Based on the pilot’s reported misunderstanding of (the autopilot) system, including, but not limited to the autopilot’s pitch inputs and the requirement for manual pitch trim application, it is possible that the pilot inadvertently mis-trimmed the airplane, which resulted in oscillations that were exacerbated by the pilot’s application of force on the control yoke,” the report stated. “These kinds of pilot-induced oscillations can occur when manual yoke or pitch trim inputs are in conflict with the autopilot’s pitch control inputs, leading to delayed, or out-of-sync, corrections, rather than a smooth, constant altitude hold. The airplane’s vertical profile as evidenced by the ADS-B data, was consistent with these kinds of pilot-induced oscillations.
“As the oscillations became stronger, the pilot may have ultimately been unable to control the airplane’s pitch, even with the autopilot disengaged, resulting in the loss of airplane control.”
All major components of the airplane were located at the accident site. The engine was partially buried in a crater that was 5 feet deep by 8 feet wide. The engine was severely damaged and the cockpit damaged by fire.
NTSB investigators did not find any evidence of precrash mechanical irregularities but noted the fragmentation and fire damage of the wreckage precluded a complete evaluation of the aircraft flight controls and autopilot system.
Due to the violence of the crash, the ability to do an autopsy was limited. However, the toxicology results determined that Blalock had ingested trazodone, alprazolam, and buspirone, drugs routinely used to treat anxiety and depression that may cause psychomotor and cognitive impairment such as slowed reaction time, diminished situational awareness, and sedation. The use of these medications is considered disqualifying for pilots.
Two video recording devices were discovered in the wreckage. Both units appeared intact with superficial exterior damage and retained their respective micro-SD data cards. The units were retained and delivered to the NTSB Recorders Laboratory for examination and download.
“Examination and testing revealed that the memory card from one of the devices was destroyed beyond repair, and no data was recoverable,” the NTSB report stated. “The memory card from the other device did not contain any video recordings, and a forensic examination recovered only deleted files from previous flights and revealed that the camera was likely not recording during the accident.”
The complete NTSB final report can be found below:
