NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The private pilot downloaded official weather briefings onto his tablet computer the night before and again on the morning of the planned cross-country personal flight. The forecast conditions were not conducive to visual flight and included a series of storms passing through the intended flight route, which resulted in instrument meteorological conditions (IMC), high cloud tops, and the potential for icing and mountain obscuration. Despite these forecasts, the low-time, noninstrument-rated private pilot departed with his wife and their three children for the intended vacation, which included a surprise party later that night.
According to Federal Aviation Administration radar tracking data, shortly after departure, the flight began to encounter the forecast weather conditions, and the flightpath and altitude began to change as the pilot repeatedly deviated to avoid clouds. Air traffic control (ATC) personnel provided the pilot with regular reports of bands of precipitation and the potential for airframe icing along the intended direction of flight. However, the pilot chose to continue the flight, and the cloud tops ahead continued to rise. The pilot kept climbing the airplane to remain clear of the cloud tops and eventually reached an altitude close to Class A airspace, where an instrument flight rules (IFR) clearance would be required, and close to the airplane's approved operating ceiling of 20,000 ft. The flight continued, but the airplane then began descending, and shortly after, the airplane likely entered the clouds.
An air traffic controller then offered the pilot the option to obtain an IFR clearance and continue the flight. Despite his lack of both an instrument rating and his limited experience flying in IMC, the pilot accepted. Radar data indicated that, during this period, the airplane turned abruptly left, directly toward a region of heavy precipitation. Then, shortly after accepting the IFR clearance, and likely while the pilot was distracted from controlling the airplane as he configured the airplane's avionics, the flightpath became erratic. The airplane performed a rapid descending left turn, after which the pilot transmitted a distress call. The flight continued to progress erratically, and the pilot made another distress call, after which the controller provided the pilot vectors to a nearby airport; however, no response was received. Subsequently, an alert notice was issued for the airplane, and the wreckage was located a few hours later.
Analysis of the debris field, airplane component damage patterns, and fracture surfaces indicated that both wings and stabilator halves separated from the fuselage in flight due to overstress resulting from excessive air loads. These air loads were likely induced by the pilot during his attempt to regain airplane control, which he lost shortly after the airplane entered the clouds. All persons on board were ejected from the airplane during the breakup sequence and sustained fatal injuries.
The reasons for the loss of control were likely the pilot's inability to maintain airplane control in IMC; his spatial disorientation, as evidenced by the erratic flightpath; airframe icing; pitot-static system icing; or some combination thereof. Icing could not be ruled out because the airplane was in visible moisture and flew directly into and toward precipitation just before the diversion.
Although the airplane was equipped with an autopilot, variations in heading and altitude throughout major portions of the flight suggested that the pilot was likely hand-flying the airplane. According to one of the airplane's owners, the autopilot was operational. However, the primary autopilot components were destroyed during the accident; thus, its operational status could not be determined.
The pilot had planned for the flight to last just over 2 hours and, based on his departure time, would have landed just before sunset. However, because of the weather deviations, the airplane had only reached the half-way point when the accident occurred, with about 30 minutes remaining before sunset.
The airplane was only equipped with a supplemental oxygen system sufficient for three persons. However, for more than half of the flight duration, the airplane was operating at altitudes that required all five occupants to be provided with and using oxygen. An oxygen mask was found entangled with the pilot's jacket, and the relative clarity of his communications with air traffic control suggested that he was using supplemental oxygen.
Given the pilot was not rated for IFR and did not have adequate oxygen equipment for his family, he may have been reluctant to declare an emergency and request a climb above flight level 180 and into class A airspace, which would likely have taken him into visual meteorological conditions, but instead accepted the IFR clearance at a lower level that did not ensure he could remain clear of clouds. His decision-making under increasingly adverse conditions was likely driven by a desire to get his family to the destination for the scheduled event that evening.
Although the pilot's autopsy identified significant coronary artery disease, there was no evidence of an old or new heart attack. Further, the pilot's radio communications and subsequent distress call revealed no evidence to support pilot impairment or incapacitation due to the coronary disease.