33 fatalities

1977-09-04: Vickers Viscount (HC-BCL) — SAN Ecuador - Servicios Aéreos Nacionales — Cuenca-Mariscal La Mar, Ecuador

Cuenca-Mariscal La Mar, EcuadorLanding (descent or approach)

On September 4, 1977, a Vickers Viscount (registration HC-BCL) operated by SAN Ecuador - Servicios Aéreos Nacionales was involved in an aviation accident near Cuenca-Mariscal La Mar, Ecuador during landing or approach. 33 people were killed. Investigators recorded the probable cause as: The crew was flying VFR mode in adverse weather conditions, resulting in a controlled flight into terrain. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 3 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781227594Data APIEditorial standards

A four-engine airplane struck a mountainside while descending to Cuenca-Mariscal Lamar Airport in poor weather, killing all 33 aboard. The crew was flying under VFR in IMC conditions, leading to controlled flight into terrain.

Accident Details

On approach to Cuenca-Mariscal Lamar Airport, a four-engine airplane descended through poor weather conditions and collided with the slope of a mountain in the Cajas Mountain Range. The impact occurred approximately 40 km north of the intended destination. The wreckage was located several hours after the crash. All 33 persons on board were killed.

Investigation Findings

Investigators determined that at the time of the accident, the aircraft was operating in instrument meteorological conditions (IMC). The crew, however, was conducting the approach under visual flight rules (VFR) mode.

Probable Cause

The probable cause of the accident, as stated in the official findings, was that the crew was flying VFR mode in adverse weather conditions, resulting in a controlled flight into terrain.