20 fatalities

Aircraft Collides with Slope During Flight in Poor Weather (PP-YPM)

Ribeirão Claro, BrazilFlight

On December 1, 1949, a Douglas C-47 Skytrain (DC-3) (registration PP-YPM) operated by Real Aerovias was involved in an aviation accident near Ribeirão Claro, Brazil in flight. 20 people were killed. Investigators recorded the probable cause as: The captain was imprudent and showed a lack of discipline in continuing the flight in VFR mode in IMC conditions. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-08-05Data APIEditorial standards

An aircraft on a scheduled flight from São Paulo-Congonhas to Londrina struck the slope of Serra dos Ruvina after weather deteriorated. The ADF had failed; the captain was overruled by operations. Two occupants survived.

Incident Overview

On a morning flight from São Paulo-Congonhas Airport to Londrina with an intermediate stop in Jacarezinho, the aircraft experienced a failure of the onboard ADF system. The captain, aged 23, decided to return to Congonhas. However, the operations staff disallowed the return and forced the crew to continue the flight. Shortly thereafter, weather conditions worsened, with low clouds and heavy rain reducing visibility significantly. While flying at an insufficient altitude, the aircraft struck the slope of the Serra dos Ruvina near Ribeirão Claro.

Casualties and Survivors

Two passengers, a woman and her 5-year-old child, were rescued from the scene. The remaining 20 occupants of the aircraft were killed.

Investigation Findings

The official investigation determined that the captain was imprudent and showed a lack of discipline by continuing the flight in visual flight rules (VFR) mode under instrument meteorological conditions (IMC), characterized by poor visibility due to low clouds and heavy rain. Additionally, experts held the head of operations partially responsible for disallowing the pilot to return to Congonhas Airport and forcing him to continue the flight despite the adverse weather.

Probable cause

The captain was imprudent and showed a lack of discipline in continuing the flight in VFR mode in IMC conditions. Additionally, the head of operations disallowed the pilot to return to Congonhas Airport and forced him to continue the flight despite the poor weather conditions.