N56DV

HISTORY OF FLIGHTOn October 1, 2023, about 1030 Pacific standard time, an experimental amateur-built Cub Crafters CCK-1865, N56DV, was substantially damaged when it was involved in an accident near Twisp, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight.

The pilot planned to take a local flight with his friend, who owned the same make of airplane. They departed a private airfield in their respective airplanes and flew directly to a hillside about 2 nautical miles away. The friend landed uphill on the slope of the hillside and positioned his airplane to the west of a tree. Using the radio, he communicated to the pilot that he should land his airplane in between his airplane and the tree. The pilot made two low passes over the ridge, performing reconnaissance over the landing area. The friend saw the airplane touch down on the slope further to the east of his location and land upslope. After a short landing roll, the pilot appeared to abort the landing, and the airplane became airborne again. The friend then saw the airplane collide with a large rock, resulting in the airplane’s left landing-gear folding under the fuselage.

The friend observed that the airplane continued over the ridge to the east (the presumed bail-out path), and then lost sight of it. He asked the pilot over the radio if he was okay, and the pilot replied, “I’m flying, but I’m having problems.” The airplane collided with terrain shortly thereafter.

A download of the non-volatile memory from the onboard Dynon SV-HDX1100 avionics system provided the airplane’s position information and various engine parameters. The data revealed that the airplane departed about 1025 and made a gradual, climbing left turn to the hillside where the pilot intended to land. The airplane then made a right 360° turn followed by a left 360° turn. Thereafter, the flight path descended toward terrain and, at 1030:09, continued past the rock that the airplane reportedly struck. The airplane made a gradual left turn until the flight track ended at 1030:37. The last recorded data point, about 325 ft from where the main wreckage was found, recorded an airspeed of about 63 kts and a left roll of about 50° (see figures 1 and 2 below).

Figure 1: Entire flight path in reference to the main wreckage.

Figure 2: Last portion of the flight path

The recorded engine data indicated that rpm, fuel pressure, oil pressure, exhaust gas temperature, and cylinder head temperature remained consistent with values typical of normal operation. These parameters did not fluctuate or deviate significantly from those recorded on prior flights. WRECKAGE AND IMPACT INFORMATIONThe airplane came to rest about 1,700 ft to the northeast of the rock it reportedly struck, with an approximate 3,430-ft peak between the locations.

The wreckage was found distributed over 90 ft on a median magnetic bearing of about 250°. The first identified points of contact consisted of disrupted dirt on the upslope of a hillside making up the far northeastern end of the debris field. The disruption in the terrain contained chips of silver paint and small pieces of fabric. The disrupted dirt widened into a crater that continued toward the wreckage with numerous vortex generators in the dirt and outboard wingtip structure. A large portion of the forward left-wing tip was 25 ft from the wreckage, and pieces of plexiglass and splinters of propeller led up to the wreckage. Fragments of the wooden propeller surrounded the accident site and made up the farthest debris to the south.

The fuselage came to rest on its left side with the right wing folded forward over the engine (see figure 3). The left wing sustained crush deformation and came to rest inverted. The left forward and aft lift struts had separated but remained attached to their respective fittings on the fuselage and wing. An approximate 1.5-ft piece of the left aft lift strut remained attached to the airframe; the trailing edge of both portions of that strut contained black marks consistent with the rubber from the tire. The flaps appeared to be partially down, and the fuel selector was in the off position. (It could not be confirmed whether first responders manipulated the fuel selector.)

Figure 3: Main wreckage

Both tires came to rest near the belly pod. The left tire was flat and showed several gouges and scrapes on the rubber; the metal hub was bent and folded over itself in one area (see figure 4). The landing gear struts were collapsed, and the bottom of the left struts were separated, with damage consistent with being dragged across terrain.

Figure 4: Left main tire

The fuselage frame behind the left lift-strut fork and gear-strut connection fittings was deformed. The left aileron pulley, adjacent to the deformed frame, would not move. The aileron cable was trapped between the frame, and the pulley and could not move (see figure 5). Removal of the pulley hardware revealed that the pulley bracket was bent, and there was evidence of the cable rubbing against the bracket and part of the airframe. The phenolic pulley had a groove for the cable that extended around the pulley. The groove contained a peak edge on each side. One side of the peak edge was fractured consistent with overstress. The side face of the pulley (adjacent to the fractured peak edge) contained a long, imprinted streak consistent with the location where the cable had pulled out or derailed from the groove.

Figure 5: Left aileron pulley and bracket

The initial touchdown area could not be definitively identified, but tracks in the dry grass were found on the slope consistent with the landing direction. A large rock was located on the saddle of the hill. There were numerous marks and scrapes found on the south rock face and on the top of the rock (see figure 6). In the surrounding area, there were several silver chips of paint and a zip-tie.

Figure 6: Rock with presumed landing path MEDICAL AND PATHOLOGICAL INFORMATIONThe Snohomish County Medical Examiner’s Office conducted an autopsy of the pilot. The cause of death was determined to be multiple blunt force injuries. The heart was described as globular and floppy, with dilation of both ventricles. Although visual examination of the heart was limited by trauma, no other significant natural disease was identified, nor was any found elsewhere in the examination. Toxicological testing detected celecoxib and naproxen in blood and urine samples.

The pilot did not hold a valid FAA medical certificate at the time of the accident. His last examination occurred in December 2021, when his application for a third-class medical certificate was deferred pending further evaluation. He subsequently underwent neuropsychological and psychiatric assessments following an August 2021 aviation-related incident during which he had been observed exhibiting unusual aggressive behavior. These evaluations identified deficits in learning, memory, and executive function, including reduced impulse control, self-awareness, problem-solving, and adaptability. Residual effects of a 2009 traumatic brain injury were considered a possible contributing factor.

In June 2022, the FAA denied his medical certification. He requested reconsideration in August 2022. After additional review, the FAA issued a final denial in October 2022, citing traumatic brain injury, aeromedically significant cognitive deficits, cognitive impairment, and a mental condition characterized as disinhibition due to one or more etiologies. These conditions were determined to be incompatible with aviation safety.

The denial of the pilot’s most recent application for medical certification also disqualified him from exercising sport pilot privileges, as specified in 14 CFR 61.23(c)(2)(ii).