Probable cause for fatal plane crash found

St. Paul, Minn. — Federal investigators have found a probable cause for a plane crash that killed a Minnesota pilot two years ago.

Sixty-year-old Bob Nelson of Battle Lake was flying from Bismarck, North Dakota, to Fergus Falls when he encountered thunderstorms and his plane disappeared.

NTSB investigator Todd Fox said Nelson was not trained on the instrument needed to fly in poor weather conditions, and he may not have been aware of the stormy conditions ahead of his flight:.

"There was no indication that he had obtained, requested or obtained a flight weather briefing, a pre-flight weather briefing or while he was en route a flight weather briefing from flight service station," Fox said.

Fox said Nelson did not file a flight plan and the search was difficult.

Nelson's body and the plane wreckage were found in a slough near Kulm, N.D., more than a month after he disappeared.