Struck the ground and a power pole 1,7nm short of runway 12L during a non precision approach to Victoria County-Foster Airport, Texas. PROBABLE CAUSE: “The lack of altitude awareness on the part of the flightcrew while descending into known weather conditions which were conductive to a rapid deterioration in forward visibility. The Board believes that the action of the crew might have been influenced by a visual illusory effect produced by a shallow layer of dense fog combined with the relative position of the sun.”