The NTSB has released its preliminary report into a Florida plane crash that killed a UK professor and his pilot.
David Maehr's plane went down near the airport in Lake Placid. The biology professor was surveying black bears in the area at the time.
The NTSB report indicates the plane had several significant modifications and had just refueled half-an-hour before it went down.
Inspectors say it crashed in a near vertical, nose-down position, with a lot of twisting and bending in the fuselage.