KOKOMO, Ind. (WISH) — The investigation of a fatal crash of a small airplane last week in a Howard County soybean field has centered on jet fuel.

The pilot ordered jet fuel for the plane that lead to spark plug damage “consistent with detonation,” a preliminary report from the National Transportation Safety Board said.

The crash of the Piper Aerostar 602P happened about 4:30 p.m. Saturday off State Road 22 near County Road 300 East. The plane had just departed Kokomo Municipal Airport.

Dr. Daniel P. Greenwald, 59, of Tampa, Florida, piloted the plane and died in the crash, the county coroner said Sunday. The plastic surgeon was the sole occupant of the plane.

The report said the plane has arrived at the Kokomo airport about 10:30 a.m. Saturday from Peter O. Knight Airport in Tampa.

“The purpose of the flight was for the pilot, who was employed by In Flight Review, Inc, based in Tampa, Florida, to provide Piper PA-42 Cheyenne recurrent training to a customer based at” the Kokomo airport, the NTSB report said.

The plane was registered to Indiana Paging Network Inc. and operated Saturday as a business flight without a flight plan.