Federal investigators say pilot error is to blame for a western Iowa plane crash last month that killed a pilot. The National Transportation Safety Board says the crop-dusting plane struck a tree southeast of Moville shortly before noon on August 11th. The pilot, 44-year-old Alan Foster of Dallas Center, died in the crash. The N-T-S-B report says the crash was due to the pilot’s inadequate in-flight planning and failure to maintain adequate clearance from the tree. A farmer told authorities Foster was flying low to miss power lines near the field.