CEN20FA049

The pilot’s failure to set the elevator trim properly for takeoff, which resulted in an exceedance of the airplane’s critical angle of attack during climb out, an aerodynamic stall, and the subsequent impact with terrain.

The pilot and a passenger were departing from the airport to return to their home base airport. A witness reported that nothing was out of the ordinary on the airplane’s initial rollout. However, the airplane rotated at a much slower speed than would be expected and immediately started to climb at a very high pitch attitude. The witness reported that as the airplane gained altitude, it appeared to fly slower to the point that the left wing stalled, causing the airplane to nose over and continue its trajectory straight into the ground just east of the runway. The witness stated that the engine power was “on” throughout the entire flight. Videos recorded near the accident site and the accident airplane’s engine monitor data were consistent with the witness description of the accident flight. The airplane did not exhibit any in-flight fire or smoke in the videos, and a ground fire was observed after impact. The pilot had purchased the airplane about 1 month before the accident and, according to his flight instructor, had accumulated 6.8 hours of instructional flight time. A disassembly examination of the engine revealed no preimpact anomalies that would have precluded normal operation. Review of photographs of an exemplar trim jack screw and the accident airplane’s jack screw revealed that the airplane’s trim system components exhibited a setting consistent with a full nose-up trim. The before takeoff checklist for the airplane make and model includes the step, “Elevator Trim….TAKEOFF SETTING.” The autopsy did not detect any significant natural disease. Toxicology testing detected a muscle relaxant and an antinausea medication in the pilot’s liver and muscle tissue samples; it was unknown why the pilot was using these impairing medications. The witness who saw the pilot before he took off observed nothing out of the ordinary in the pilot’s behavior and “no red flags” with respect to the pilot‘s actions. Thus, it could not be determined if effects from the pilot’s use of a muscle relaxant and an antinausea medication were factors in this accident. A low level of carbon monoxide was detected in the pilot’s blood. The concentration would not be at a level to cause impairment and thus was determined not to be a factor in the accident. Given the available information, it is likely the pilot departed with the elevator trim set to a full nose-up setting as opposed to the takeoff setting, which resulted in the airplane pitching up steeply after liftoff and the subsequent aerodynamic stall.

According to the FAA medical certification file and FAA medical case review, at the time of the pilot’s most recent FAA medical certification examination on May 28, 2019; he reported taking no medications and having a history of seasonal allergies. No significant medical concerns or issues were identified. According to the Forensic Medical of Kansas, LLC, Kansas City, Kansas, autopsy report, the cause of the pilot’s death was multiple blunt traumatic and thermal injuries. There was no evidence of any significant natural disease identified. Toxicology testing performed for the medical examiner detected the muscle relaxant cyclobenzaprine at 36 nanograms per milliliter (ng/mL) in the pilot’s chest cavity blood and reported carboxyhemoglobin at 10% saturation. FAA Forensic Sciences Laboratory toxicology testing detected cyclobenzaprine and its active metabolite norcyclobenzaprine in the pilot’s liver and muscle tissue. Ondansetron was detected in both liver and muscle tissue. Dextromethorphan was detected in liver and muscle tissue, while its metabolite dextrorphan was only detected in liver tissue. Cyclobenzaprine is a prescription medication commonly marketed as Flexeril. It is indicated for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Norcyclobenzaprine is the major metabolite of cyclobenzaprine. Cyclobenzaprine carries the warning that its use may impair mental or physical abilities required for performing hazardous tasks. The therapeutic range for cyclobenzaprine is 5 to 40 ng/mL and its half-life averages around 18 hours. Ondansetron is a prescription medication commonly marketed as Zofran. It is indicated for use in preventing nausea and vomiting from chemotherapy, radiation therapy, or surgery; however, it is frequently prescribed for off-label purposes. While ondansetron itself would be considered impairing, the condition for which it would be prescribed would also need to be evaluated for flying safety. Ondansetron’s side effects may include fatigue and dizziness. Dextromethorphan is a nonsedating, over-the-counter cough suppressant that is no impairing. Carbon monoxide (CO) is an odorless, colorless gas that is a byproduct of combustion, such as from an exhaust system or fire. Carboxyhemoglobin is formed when CO binds to hemoglobin, the protein in red blood cells that carries oxygen. The degree of carboxyhemoglobin formation is related to the concentration of CO and the duration of exposure. The binding of CO impairs oxygen transport and use, and results in symptoms of exposure that can be mild and vague to impairing and incapacitating. Carboxyhemoglobin levels above 5% in nonsmokers and above 10% in smokers would suggest exposure to CO. According to a flight instructor, the pilot was given instruction in the Mooney to include basic maneuvers, takeoffs, landings, airport entry activities, cross-country activities, and go-arounds. The pilot was given instruction in using an after landing checklist that included setting flap, mixture switches, and trim for takeoff. He characterized the pilot as a “quick learn” and an “excellent student.” The instruction totaled 6.8 hours of flight time. A review of Federal Aviation Administration (FAA) records showed the pilot and a co-owner purchased the airplane on November 26, 2019. The airplane did not receive any fuel at OJC. According to the pilot operating handbook, the entire empennage pivots around its main hinge points to provide pitch trim control. The system consists of a manually operated actuator that operates a series of torque tubes and universal joints connected to a jack screw on the aft tailcone bulkhead. A trim control wheel, located between the pilot and copilot seats, allows the pilot to set the stabilizer trim angle. Trim position is indicated by an electrical gauge located in the center flight panel. This indicates the stabilizer position relative to the aircraft thrust line. The before takeoff checklist stated, in part, “Elevator Trim ... TAKEOFF SETTING.” Mooney issued Service Bulletins (SB) M20-313A, “Empennage Trim Fitting And Mounting Hardware Inspection,” and M20-314A, “Empennage Trim Fitting And Mounting Hardware Replacement Instructions,” on February 29, 2012, to require a one-time inspection to ensure the trim filler plate is positioned correctly with the trim fitting and trim hinge. SB M20-314A listed compliance as mandatory, before the next flight. On March 20, 2012, the FAA issued Airworthiness Directive (AD) 2012-05-09, which required inspecting the trim fitting, hinge, and filler plate of the tail pitch trim assembly for correct positioning and proper attachment, and inspecting the Huck Bolt fasteners for proper security on all Mooney models, including the accident airplane. The AD was prompted by a report of an incident on a Mooney M20TN airplane regarding failure of the tail pitch trim assembly, which could result in a loss of control, and the potential for this condition to exist on other airplane models. A mechanic who had worked on the accident airplane was advised that the airplane logbooks were not located and was asked if the SBs and AD had been accomplished. He stated, in part, that those items were not shown on the work order but would have shown on the AD list. He indicated that “it is a normal part” of the annual checklist and that he was sure it was complied with previously or it would have been listed on the work order as an action item. The wreckage was oriented about 171° and about 2,550 ft from the departure threshold of runway 18. Major components of the airplane were identified at the accident site. The top of the fuselage was consumed by fire between the instrument panel to just forward of the empennage. The lower section of the fuselage was discolored, deformed, and melted. The engine compartment exhibited aft migration of the engine against the firewall. The propeller was embedded in terrain; examination after recovery revealed “S”-shaped bending and leading-edge nicks. The empennage and fuselage aft of the cabin were bent laterally toward the left wing about 30°. The leading edge of the right wing exhibited aft crushing. The leading edge of the left wing exhibited discoloration, melting, and deformation. The position of the left main landing gear could not be determined due to the left wing’s thermal damage. The right main landing gear was found partially extended. Flight control continuity from all the flight control surfaces to the cabin area was traced. The ignition key switch was set to the BOTH position. The mixture, propeller, and throttle control knobs were in their forward positions. Examination of the engine compartment confirmed control continuity of the mixture, propeller, and throttle controls from their engine accessories to their respective cockpit controls. The airplane instrument panel was damaged by impact forces and thermal damage. The JP Instrument (JPI) EDM 800 unit exhibited impact and thermal damage and was shipped to the National Transportation Safety Board (NTSB) Recorder Laboratory to determine if it contained data in reference to the accident flight. Data with respect to 7 engine parameters, time, outside air temperature, and electrical bus voltage, was extracted and included 12 sessions with the final session determined to be related to the accident flight. An engine disassembly examination was conducted. There were no preimpact anomalies detected during the examination that would have precluded normal operation. A fixed-base operator that services Mooney airplanes supplied photographs of an exemplar trim system jack screw at takeoff and full up trim settings; when the trim indicator was in the full up position, the jack screw was at its full extension. A postaccident photograph of the accident airplane’s trim jack screw was consistent with the full up trim setting in the exemplar photographs.