Investigators say the pilot in the crash that killed Senator Paul Wellstone made errors during two previous campaign flights that prompted his co-pilots to take over the controls.
Three days before the fatal crash, Richard Conry hit a wrong switch, causing the plane to pitch downward at 300 feet off the ground. The co-pilot corrected his action.
The National Transportation Safety Board voted unanimously Tuesday that pilot error caused the crash that killed Wellstone, his wife, daughter, three campaign workers and both pilots.
No mechanical problems were found. One investigator said the pilots were approaching a runway too fast, then overcorrected, slowing the plane to a stall.
The board recommended FAA inspectors periodically fly on small charter planes to ensure safe flight operations. It also recommended more training on how flight crews should work together.