N662DA

The student pilot/owner reported that he was flying eastbound with a passenger along two dirt roads, a set of power lines, and a canal that were all oriented east-west and parallel to one another. As the airplane flew along the canal, a "downdraft" or "rotor" caused a sudden loss of altitude which placed an intersecting (north/south) set of power lines, which crossed the canal, directly in its flight path. The pilot attempted to fly under the power lines to avoid them, but struck a tree on the canal's bank, and the airplane then impacted the water and submerged, which resulted in substantial damage to the airframe. Witnesses reported to the FAA that the airplane was flying just above the canal, below the height of the parallel lines, when it descended further, struck the tree, and the water. The student/pilot owner stated that there were no mechanical deficiencies with the airplane that would have prevented normal operation.