ERA19FA266

The pilot's failure to maintain a positive climb rate after takeoff due to spatial disorientation, which resulted in the airplane’s descent into water.

The pilot had planned a cross country instrument flight rules (IFR) flight but had not contacted air traffic control to receive an IFR clearance before departing. He was departing from a coastal airport during dark morning hours, prior to sunrise, and after takeoff made a right climbing turn. The airplane reached an altitude about 400 feet above the ground, about 90° through the turn, before descending in the turn and impacting the water. The airplane’s groundspeed continued to increase, from about 70 knots at liftoff, to 100 knots at the height of the right climbing turn, to 146 knots at the end of the data. Review of airport surveillance video depicted the airplane’s takeoff, initial climb, and turn toward an area of dark open water underneath a scattered cloud layer. Based on the dark night conditions and the lack of visual reference at the time of the accident, it is likely that the pilot became spatially disoriented, which led to the subsequent descent into water. Examination of the wreckage revealed a right-wing-low attitude at the time of the impact, which was consistent with the pilot maintaining the right turn seen in the surveillance video recordings. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or abnormalities that would have precluded normal operation. The pilot held an instrument rating, but no logbook information was available from which to determine his level of instrument currency or proficiency. According to medical certification files, the pilot had several eye disorders including chronic macular edema in his right eye and bilateral glaucoma; both conditions restrict visual fields. A year prior to the accident, the pilot had successfully completed a medical flight test and had been granted a statement of demonstration ability (SODA) by the Federal Aviation Administration for his right visual field defect. The medical flight test included, among other abilities, demonstrating the ability to judge distances and to recognize landmarks and the ability to read instrument panels quickly and correctly. The medical flight test is administered during daytime hours; in this accident, the pilot departed the airport under night visual conditions and then flew over the ocean which would have few visual cues. It is therefore unknown how well this pilot could respond under dark conditions. The challenge with a constricted visual field is not generally the speed to execute the visual scan, but the time to process the visual information. Given the lack of information from no nighttime vision testing as part of his SODA and insufficient information on the pilot’s instrument flight capabilities, the investigation was unable to determine what role, if any, the pilot’s vision restrictions contributed to this accident.

The pilot held a commercial pilot certificate with ratings for airplane single-engine land and instrument airplane. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued on February 10, 2018. At that time, he reported a total flight experience of 1,500 hours. The pilot’s logbook was not recovered. The pilot’s total and recent instrument experience could not be determined. The wreckage was examined following its recovery from the water to a storage facility. Both wings and the engine separated during impact. The right wing exhibited more impact damage than the left wing. The right flap separated, and its actuator was found in the retracted position. The left flap remained attached, exhibited impact damage, and was partially extended. The right aileron separated and only small pieces of it were recovered. The left aileron remained partially attached to a separated section of left wing. Both wingtip sections separated and were not recovered. The right horizontal stabilizer and right elevator exhibited leading edge damage and separation at the outboard section. The left horizontal stabilizer and left elevator were less damaged. There was no damage to the vertical stabilizer or rudder. The landing gear was retracted. Control continuity was confirmed from all control surfaces (except for the right aileron) through cable breaks at the fuselage, to the cockpit controls. The cable breaks exhibited broomstraw features consistent with overload separation. Pieces of the right aileron were recovered but the right aileron bellcrank was not recovered. The right aileron cable was recovered and exhibited broomstraw features consistent with overload separation. Measurement of the elevator trim jackscrew corresponded to an approximate neutral elevator trim position. The cockpit was crushed and separated from the fuselage. The pilot and copilot seats were not recovered. The fuel selector valve was positioned to the left fuel tank. The attitude indicator gyro was disassembled for examination. Its rotor and housing were corroded. The directional gyro was also disassembled for examination. It’s rotor and housing were corroded; however, one rotational score was observed on the housing. The vacuum pump was disassembled, its rotor, vanes, and shear shaft remained intact. Fuel was recovered from the fuel selector valve and the fuel manifold. It was consistent in color and odor to 100 low lead aviation gasoline. The propeller separated from the crankshaft flange. One propeller blade was twisted while the other blade was bent aft and exhibited a leading edge gouge. The spark plugs were removed and their electrodes were intact and gray in color. The crankshaft was rotated by hand via the propeller flange. Camshaft, crankshaft, and valve train continuity were confirmed to the rear accessory section of the engine. Thumb compression was attained on all cylinders. Borescope examination of the cylinders did not reveal any anomalies. Both magnetos produced spark at all posts when rotated via an electric drill. The engine driven fuel pump remained attached and could be rotated by hand. It was then disassembled and no anomalies were noted. The oil filter was opened and its element was absent of contamination. The fuel metering unit remained partially attached to the engine and did not exhibit any anomalies. HISTORY OF FLIGHT On September 8, 2019, at 0630 eastern daylight time, a Cessna 210A, N9436X, was destroyed when it impacted the Gulf of. The commercial pilot and passenger were fatally injured. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot had filed an instrument flight rules (IFR) flight plan for the accident flight, with a planned destination of Savannah/Hilton Head International Airport (SAV), Savannah, Georgia. On the morning of the accident flight, the pilot was departing from The Florida Keys Marathon International Airport (MTH), Marathon, Florida but had not contacted air traffic control to receive an IFR clearance. Review of ADS-B track data for the accident flight revealed that it departed on runway 25 at 0629 and initially made a right climbing turn. The airplane reached an indicated altitude of 425 ft mean sea level about 90° through the turn, before descending in the turn and impacting the water. The airplane’s groundspeed continued to increase, from about 70 knots at liftoff, to 100 knots at the height of the right climbing turn, to 146 knots at the end of the data. Review of airport surveillance video depicted the airplane’s takeoff, initial climb, and turn toward an area of dark open water underneath a scattered cloud layer. The recorded weather at MTH, at 0653, included: visibility 10 miles and scattered clouds at 2,800 ft. Review of data from the U.S. Naval Observatory revealed that civil twilight began at 0645 and sunrise was at 0708. Spatial Disorientation The FAA's Pilot's Handbook of Aeronautical Knowledge contained guidance which stated that "under normal flight conditions, when there is a visual reference to the horizon and ground, the sensory system in the inner ear helps to identify the pitch, roll, and yaw movements of the airplane. When visual contact with the horizon is lost, the vestibular system becomes unreliable. Without visual references outside the airplane, there are many situations where combinations of normal motions and forces can create convincing illusions that are difficult to overcome." The Handbook also advised, "unless a pilot has many hours of training in instrument flight, flight in reduced visibility or at night when the horizon is not visible should be avoided." The FAA Airplane Flying Handbook (FAA-H-8083-3) described some hazards associated with flying when visual references, such as the ground or horizon, are obscured. "The vestibular sense (motion sensing by the inner ear) in particular tends to confuse the pilot. Because of inertia, the sensory areas of the inner ear cannot detect slight changes in the attitude of the airplane, 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." FAA Publication "Spatial Disorientation Visual Illusions" (OK-11-1550), states in part "false visual reference illusions may cause you to orient your aircraft in relation to a false horizon; these illusions are caused by flying over a banked cloud, night flying over featureless terrain with ground lights that are indistinguishable from a dark sky with stars, or night flying over a featureless terrain with a clearly defined pattern of ground lights and a dark starless sky." The publication further provides guidance on the prevention of spatial disorientation. One of the preventive measures was "When flying at night or in reduced visibility, use and rely on your flight instruments." It further states "if you experience a visual illusion during flight (most pilots do at one time or another), have confidence in your instruments and ignore all conflicting signals your body gives you. Accidents usually happen as a result of a pilot's indecision to rely on the instruments." The FAA publication Medical Facts for Pilots (AM-400-03/1), described several vestibular illusions associated with the operation of aircraft in low visibility conditions. Somatogravic illusions, those involving the semicircular canals of the vestibular system, were generally placed into one of four categories, one of which was the "graveyard spiral." According to the text, the graveyard spiral, "…is associated with a return to level flight following an intentional or unintentional prolonged bank turn. For example, a pilot who enters a banking turn to the left will init