Austral flight 901 departed Tucum n at 09:11 for a flight to Buenos Aires. The flight was uneventful and at 10:35 the Tower controller cleared the flight to descend to 750 metres to the San Fernando VOR and cleared the flight for a direct approach to runway 13 from the VOR. At 10:40 the flight reported over the OP VOR and was cleared to land. The wind had shifted from 6 knots at 60 degrees to 12 knots at 030 degrees. Visibility was reducing. At 10:42 the crew reported the runway in sight and obtained the current weather information, which included heavy rainfall, wind 360 degrees at 10 knots. The pilots lost sight of the runway and decided to abort the approach. The One-Eleven continued South to the Quilmes (ILM) NDB. The Tower controller cleared the flight to hold over the ILM beacon at 900 metres. Because of Cumulonimbus clouds over the NDB, the crew requested a holding pattern over the R¡o de la Plata at 600 metres. At 10:52 they were cleared for another straight in approach to runway 31. Shortly afterwards the pilots lost control of the plane, which crashed into the river. Just 55-65% of the wreckage was recovered; both FDR and CVR were not found after 42 days of searching. PROBABLE CAUSE: “Loss of control of the aircraft and impact with the water by an error of appreciation by the pilot in assessing the meteorological conditions on crossing through a zone of influence of an extremely violent cumulonimbus.” (Junta de Accidentes de Aviacion Civil)