VFR into IMC · NTSB ANC12FA009
CESSNA 207 — Chuathbaluk, AK
| Date | November 29, 2011 |
| Location | Chuathbaluk, AK |
| Aircraft | CESSNA 207 |
| Purpose of flight | Positioning |
| Conditions | Night/Dark · Visual Meteorological Cond |
| Phase / occurrence | Enroute Loss of visual reference |
| Pilot age | 61 |
| Pilot total time | 10,000 hrs · High time |
| Time in type | Unknown |
| Fatalities | 1 |
Probable cause
NTSB findings
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- Environmental issues-Conditions/weather/phenomena-Ceiling/visibility/precip-Below VFR minima-Contributed to outcome
- Personnel issues-Psychological-Perception/orientation/illusio-Situational awareness-Pilot - C
What happened
The pilot departed on a positioning flight during dark night, marginal visual meteorological conditions. A witness, who was waiting for the airplane at the destination airport, stated that shortly after the pilot-controlled airport lighting activated, a snow squall passed over the airport, greatly reducing the visibility. The accident airplane never arrived at its destination, and a search was initiated. The airplane’s fragmented wreckage was discovered early the next morning in a wooded area, about 2 miles from its destination.
A review of archived automatic dependent surveillance-broadcast (ADS-B) data received from the accident airplane showed that the pilot departed, and the airplane climbed to about 700 feet above ground level. The airplane remained at about 700 feet for about 3 minutes, and then entered a shallow right-hand descending turn, until it impacted terrain.
On-site examination of the airplane and engine revealed no preaccident mechanical anomalies that would have precluded normal operation. The cockpit area was extensively fragmented, thus the validity of any postaccident cockpit and instrument findings was unreliable. Likewise, structural damage to the airframe precluded the determination of flight control continuity. A postaccident examination of the engine and recovered components did not disclose any evidence of a mechanical malfunction.
Given the witness account of worsening weather conditions at the airport just before the accident and the lack of mechanical anomalies with the airplane, it is likely that the accident pilot encountered heavy snow and instrument meteorological conditions while approaching the airport. It is also likely that the pilot became spatially disoriented during the unexpected weather encounter and subsequently collided with terrain.