1969-12-05: Lockheed 18 LodeStar (N410M) — Troy G. Hawkins — Albuquerque, United States of America

11 fatalitiesAlbuquerque, United States of AmericaFlight

An aircraft traveling from Las Vegas to Dalhart crashed in an open field following a wing separation caused by severe weather and structural overload.

What happened

While operating a flight from Las Vegas toward Dalhart, Texas, the crew encountered significant meteorological challenges, including turbulence and icing. Despite being rated only for Visual Flight Rules (VFR), the pilot elected to proceed through the deteriorating conditions. Shortly after entering the adverse weather, the aircraft experienced a catastrophic structural failure when the left wing detached from the fuselage. This loss of control resulted in an uncontrolled descent into an open field, where the impact triggered a large explosion. The accident resulted in 11 fatalities.

Findings

Investigations concluded that the crash was the result of an airframe failure during flight. Several contributing factors were identified, most notably that the pilot continued VFR operations into weather containing icing and freezing rain without the benefit of de-icing equipment. The accumulation of ice on the airframe, combined with the pilot's decision to fly in such conditions, led to the aircraft exceeding its designed stress limits. This ultimately caused an overload failure of the wing spars, leading to the separation of the left wing during the flight.

Probable cause

The structural failure and subsequent loss of control were caused by the pilot operating a non-de-icing equipped aircraft into icing conditions, which led to an aerodynamic overload and wing separation.