N100JB

HISTORY OF FLIGHT

On January 7, 2019, about 1050 Pacific standard time, a Beech A36, N100JB, was destroyed when it was involved in an accident near Colusa, California. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

A witness located at Colusa Airport (O08) reported that he saw the airplane taxi out and heard the pilot announce his departure from runway 13 on the airport's common traffic advisory frequency. The witness estimated that at that time, the cloud ceiling was about 500 ft above ground level with visibility of about 1 mile.

Information provided by the Federal Aviation Administration (FAA) revealed that the pilot was issued an instrument flight rules clearance to Palo Alto, California, before departure; however, he did not contact air traffic control after departure. Radar data showed that the airplane departed runway 13 at O08 and turned to a southwesterly heading. (Figure 1) About 10 seconds later, as the airplane ascended through about 725 ft mean sea level (msl) and had a groundspeed of about 130 knots, a right turn was initiated. During the initial portion of the turn, the airplane continued to ascend to about 825 ft msl, where it remained for about 7 seconds. The data showed that the airplane then began a descent, with an increase in groundspeed, while continuing the right turn for about 15 seconds until radar contact was lost. The last recorded radar target was within the vicinity of the accident site and showed an altitude of 75 ft msl and a groundspeed of about 160 knots.

Figure 1: Radar Data Flight Path and Accident Site and Airport Locations

PERSONNEL INFORMATIONThe pilot did not possess a valid medical certificate at the time of the accident. His most recent medical certificate application was dated January 18, 2005, at which time he reported 1,500 hours of total flight experience. Review of FAA records showed that the pilot had reported hay fever and knee pain along with intermittent use of chlorpheniramine (a sedating antihistamine available over the counter and often marketed with the name Chlor-TriMeton). Correspondence sent to the FAA in May 2006 stated that the airman had a diagnosis of bipolar affective disorder type II, a history of attempted suicide, and had been prescribed Effexor (generic: venlafaxine), Wellbutrin (generic: bupropion), and Lamictal (generic: lamotrigine). The pilot surrendered his medical certificate a few months later after the FAA requested further medical information, which he declined to provide.

The pilot's logbooks were not located during the investigation.

METEOROLOGICAL INFORMATION

The terminal aerodrome forecast (TAF) issued closest to O08 was about 26 miles east of the accident site. Between 0800 and 0900, the TAF forecast wind from 180º at 9 knots, visibility better than 6 miles, ceiling broken at 3,000 ft agl, overcast ceiling at 6,000 ft, altimeter setting 30.03 inches of mercury, with a temporary period from 0900 to 1100 of ceiling broken at 1,500 ft.

A search of the FAA automated flight service station provider, Leidos, indicated that no requests from the pilot for a weather briefing or to file a flight plan were made. It is unknown what the pilot reviewed to familiarize himself with the reported and forecasted weather conditions.

WRECKAGE AND IMPACT INFORMATIONExamination of the accident site by local law enforcement revealed that the airplane impacted a water irrigation pond 1.8 miles southwest of O08. The airplane wreckage, which was mostly submerged within about 5 ft of water, was recovered to a secure location for further examination.

Examination of the recovered wreckage revealed that the airframe was fragmented into multiple pieces. The instrument panel was displaced, and multiple instruments had separated. One attitude indicator was located within the recovered wreckage and was disassembled. The gyro and gimbal exhibited extremely light scoring. One vacuum pump remained attached to an external drive assembly mounted on the firewall. The vacuum pump was disassembled, and all internal rotors and vanes were intact. The vacuum pump drive was intact and undamaged. Another vacuum pump was located within the recovered wreckage, and all internal components were separated and not located.

The left wing was bent and buckled throughout. The flap and aileron remained attached. The tip tank remained attached. The right wing was fragmented into multiple sections. The outboard tip tank, and inboard portion (gear well) of the wing were recovered. A majority of the right wing was not recovered.

Flight control continuity was unable to be established throughout the airframe. Fragments of the elevator, trim, and aileron control cables were located within the recovered wreckage. The fracture surfaces on the bellcranks and control cables exhibited evidence of being cut by recovery personnel or signatures consistent with overload separation.

The turbine engine was separated from its mount, and the compressor section was separated. The propeller gearbox and governor were separated and not recovered. The engine displayed extensive impact, crush, and fracture damage and was covered with dried mud and water residue. Multiple stages of compressor rotor blade bending and fractures opposite of rotation were observed. The gas producer turbine 1st and 2nd stage nozzles exhibited marks consistent with turbine blade tip rub.

Examination of the recovered airframe and engine revealed no preimpact anomalies that would have precluded normal operation.

ADDITIONAL INFORMATIONThe FAA Civil Aeromedical Institute's publication, "Introduction to Aviation Physiology," defines spatial disorientation as a “loss of proper bearings; state of mental confusion as to position, location, or movement relative to the position of the earth.” Factors contributing to spatial disorientation include changes in acceleration, flight in IFR conditions, frequent transfer between visual flight rules and IFR conditions, and unperceived changes in aircraft attitude.

The FAA’s Airplane Flying Handbook (FAA-H-8083-3B) describes some hazards associated with flying when the ground or horizon are obscured. The handbook states, in part, the following:

The vestibular sense (motion sensing by the inner ear) in particular can and will confuse the pilot. Because of inertia, the sensory areas of the inner ear cannot detect slight changes in airplane attitude, nor can they accurately sense attitude changes that occur at a uniform rate over a period of time. On the other hand, false sensations are often generated, leading the pilot to believe the attitude of the airplane has changed when, in fact, it has not. These false sensations result in the pilot experiencing spatial disorientation.

MEDICAL AND PATHOLOGICAL INFORMATION According to the autopsy performed by Bennet Omalu Pathology, Stockton, California, the pilot’s cause of death was high velocity deceleration injury. Extensive coronary artery disease was identified in the right, left main, left anterior descending, and circumflex arteries, which were 90-99% occluded. Microscopy demonstrated evidence of previous ischemia including myofibrillary contraction band degeneration and cytoplasmic hypereosinophilia, which was multifocal but with no visible scar on the gross evaluation. In addition, the pilot had hypertensive cardiomyopathy and the pathologist reported a clinical history of poorly controlled diabetes with damage to his kidneys as well as bipolar disease.

Toxicology testing performed by NMS Labs on cavity blood at the request of the pathologist identified venlafaxine and its metabolite desmethylvenlafaxine, bupropion and its metabolite hydroxybupropion, and lamotrigine.

Toxicology testing performed by the FAA's Forensic Science Laboratory identified zolpidem, venlafaxine and its metabolite desmethylvenlafaxine, bupropion and its metabolite hydroxybupropion, and lamotrigine in liver and muscle tissue. The zolpidem level in the pilot was too low for the lab to quantify.

Zolpidem is a Schedule IV controlled substance available by prescription for the short-term treatment of insomnia; it is often marketed with the name Ambien. It is quickly sedating; users are instructed to take it only immediately before going to bed. Particularly during the initial period after taking the drug, a variety of psychoactive effects have been described, including "sleep driving" and other potentially dangerous events.

Venlafaxine is an antidepressant that can cause a variety of psychoactive effects but has not been shown to affect safety while operating a vehicle. Bupropion is an antidepressant or an adjunct to quit smoking. Bupropion can cause a number of psychoactive effects and increases the risk of seizure. Lamotrigine is an antiseizure medication also indicated for mood stabilization in patients with bipolar disease. Lamotrigine may cause a variety of psychoactive effects; its direct effects on operating a vehicle have not been studied.