A dead goose was found in part of the flight control system of a medical helicopter that crashed in western Oklahoma last month.
The crash killed all three people on board, according to a preliminary report by the National Transportation Safety Board.
The report does not cite a suspected cause of the crash, but noted one goose was found in the helicopter's flight control system and others were found in the debris field.
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A report on the probable cause could take up to two years to complete, according to the NTSB.
Federal investigators say a dead goose was found within a medical helicopter that crashed in western Oklahoma, killing three people on board. (Robert Alexander/Getty Images)
The helicopter crashed Jan. 20 in a pasture near Hydro, about 60 miles west of Oklahoma City, as it was returning to Weatherford after taking a patient to an Oklahoma City hospital.
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The pilot and both Air Evac Lifeteam crew members, a flight nurse and a paramedic, were killed.