VFR into IMC · NTSB CEN12FA098

SOCATA TB21 — Silverton, CO

4 fatal IMC
DateDecember 3, 2011
LocationSilverton, CO
AircraftSOCATA TB21
Purpose of flightPersonal
ConditionsInstrument Meteorological Cond
Phase / occurrenceEnroute-cruise VFR encounter with IMC
Pilot age59
Pilot total time594 hrs · Building experience
Time in type217 hrs
Fatalities4

Probable cause

The non-instrument-rated pilot’s decision to embark on a flight through forecasted instrument meteorological conditions (IMC), and his subsequent flight into IMC, which resulted in the pilot’s spatial disorientation and subsequent maneuvering of the airplane in a manner that exceeded the airplane’s structural limits.

NTSB findings

  • Aircraft-Aircraft structures-Wing structure-Spar (on wing)-Capability exceeded - C
  • Environmental issues-Conditions/weather/phenomena-Ceiling/visibility/precip-Below VFR minima-Effect on personnel - C
  • Personnel issues-Experience/knowledge-Experience/qualifications-Total instrument experience-Pilot
  • Personnel issues-Experience/knowledge-Experience/qualifications-Qualification/certification-Pilot - C
  • Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - C

What happened

The non-instrument-rated pilot departed for his destination with active weather advisories for his route of flight for instrument flight rules (IFR) conditions and mountain obscuration due to clouds, precipitation, and mist. After departure, the pilot attempted to remain in visual flight rules (VFR) flight by climbing above 18,000 feet mean sea level and proceeding toward his destination. When queried by an air traffic controller, the pilot stated that he could not descend due to weather. In addition, he stated that he was not instrument rated or qualified. No further transmissions were made by the pilot. Witnesses near the accident site reported low clouds with light snow flurries. On-site wreckage distribution was consistent with an in-flight breakup. Further, an examination of the wreckage revealed signatures on the airplane’s right wing consistent with it failing in overload in the upward direction and signatures on the empennage and tail section consistent with their failure in overload in the downward direction, indicating the failures were due to loads that exceeded the airplane’s structural limits. A weather study revealed the potential for clouds at the pilot’s cruising altitude, which increased the potential for VFR flight into instrument meteorological conditions (IMC). Therefore, it is likely that the pilot encountered IMC, became spatially disoriented, and then maneuvered the airplane in a manner that exceeded the airplane’s structural limits while trying to return to level flight and avoid mountainous terrain.

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

View the official NTSB docket →