NTSB Probable Cause

A FAILURE OF THE STUDENT PILOT TO CONDUCT AN ADEQUATE PRE-FLIGHT INSPECTION TO REMOVE CONTAMINATED FUEL; A FAILURE TO MAINTAIN ADEQUATE AIRSPEED TO PREVENT AN INADVERTENT STALL. CONTRIBUTING TO THE ACCIDENT WAS AN INADEQUATE ANNUAL INSPECTION OF THE FUEL SYSTEM TO DETECT A LEAKING FUEL CAP, AND INADEQUATE SUPERVISION OF THE FLIGHT BY THE PILOT-INCOMMAND.