Sikorsky S-43 accident at Rio de Janeiro-Santos Dumont, Brazil, 13 Aug 1939 (NC16933)
On August 13, 1939, a Sikorsky S-43 (registration NC16933) operated by Pan American World Airways - PAA was involved in an aviation accident near Rio de Janeiro-Santos Dumont, Brazil during landing or approach. 14 people were killed. Investigators recorded the probable cause as: Ample evidence was obtained during the Air Safety Board's investigation of the accident that the left engine suffered a sudden loss of power at a critical time during the landing approach, although, since available evidence failed to supply any conclusive… 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.
Probable cause
Ample evidence was obtained during the Air Safety Board's investigation of the accident that the left engine suffered a sudden loss of power at a critical time during the landing approach, although, since available evidence failed to supply any conclusive explanation for this loss of power, and a detailed examination of the engine, after disassembly, revealed no indication of structural failure or mechanical defects in flight, the report stated that 'the cause of the loss of power from the left engine is unknown'. In conclusion, the accident was caused by a sudden loss of power from the left engine during the landing approach, necessitating an attempted landing under extremely hazardous conditions.
— NTSB Determination
Accident narrative
The aircraft named 'Baby Clipper' was circled over Rio and was making a normal approach to the seaplane landing area adjoining the air line's Rio base near Santos Dumont Airport, in accordance with the company's established operating procedure, when it suddenly lost power on the left engine, yawed to the left, and started a descending turn in the same direction. The airplane continued to lose altitude and to turn at a sharper and steeper angle until it struck a caisson anchored at right angles to a small island in the harbor immediately adjacent to its landing approach path. All four members of the crew and 10 passengers were fatally injured, one passenger escaping with serious and another with minor injuries. Crew: Addison G. Parsons, pilot, George B. King, copilot, Russell Jenkins, radio operator, Julio Trujillo, steward. Passengers: Henrie May Eddy, James Harvey Rogers, Robert Landman, Evaristo Gomes Miranda, Anton Ommundsen, Emanuel Valensa, Pablo Lavin, Edgar Delly Oliveira, Alberto Oliveira Santos, Lucila A. Oliveira Santos, Osvaldo Hirth, Mario Souto Lyra.
Probable cause (official findings): Ample evidence was obtained during the Air Safety Board's investigation of the accident that the left engine suffered a sudden loss of power at a critical time during the landing approach, although, since available evidence failed to supply any conclusive explanation for this loss of power, and a detailed examination of the engine, after disassembly, revealed no indication of structural failure or mechanical defects in flight, the report stated that 'the cause of the loss of power from the left engine is unknown'. In conclusion, the accident was caused by a sudden loss of power from the left engine during the landing approach, necessitating an attempted landing under extremely hazardous conditions.