CESSNA 210 — Alma, CO

What happened

The noncertificated private pilot departed on a cross-country flight to relocate his airplane for maintenance. When the airplane did not arrive at its intended destination, it was reported missing, and was found by hikers over 3 months later. Detailed radar data was not available, and the airplane's route of flight count not be determined. The wreckage was located in mountainous terrain at an elevation of 12,700 ft mean sea level. The damage to the airplane, the ground scars, and debris field were consistent with a right-wing low impact and subsequent cartwheel.

Surface analysis charts, wind profiles, and satellite images depicted conditions consistent with and conducive for moderate-to-severe turbulence and mountain wave along the route of flight. In addition, there were multiple pilot reports along the route of flight for moderate to severe turbulence and mountain wave. There was no record that the pilot obtained a weather briefing for the intended route of flight.

The examination of the airframe, engine, and related systems was limited due to terrain and elevation of the accident site. Impact damage precluded functional testing of the engine and related components.

With the exception of one flight the evening before the accident, during which the pilot experienced a brake problem, and after which a nose landing gear collapse when the pilot inadvertently retracted the landing gear on the ground, it is likely that the airplane had not flown for the previous 4 years and it did not have a current annual inspection.

The pilot had diabetes treated with insulin and respiratory issues resulting in a requirement for supplemental oxygen. Complications from these medical issues could impair his ability to safely operate an airplane. However, there was no evidence of overt symptoms on the day of the accident. Furthermore, based upon the pilot's history of failure to follow regulations it is more likely that the pilot's decisions on the day of the accident were consistent with his past disregard for rules rather than the effects of his medical condition.

Toxicological testing detected both ethanol and delta-9-tetrahydrocannibinol (THC), the primary psychoactive compound of marijuana. Due to the length of time that the remains were exposed to the environment, it is possible that the ethanol was from a source other than ingestion. The THC detected in the muscle indicates that the pilot had ingested marijuana at some point before to the accident. However, determination of impairment at or around the time of the flight from THC identified in tissues exposed to the elements for many months is not possible.

Given the pilot's history of failure to follow regulations, his decisions on the day of the accident are consistent with a demonstrated disregard for rules. Whether the airplane's lack of maintenance contributed to its performance in mountainous terrain could not be determined. In addition, the extent to which the pilot's lack of recent experience contributed to his ability to properly respond to a mountain wave turbulence encounter could not be determined. It is likely that this mountain wave encounter resulted in a loss of control and impact with terrain.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.