As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DEPARTURE, AT CRUISE, FLIGHT CREW DETECTED A HOT BURNING ODOR. FLIGHT WAS ABORTED AND ACFT RETURNED TO BASE. MECHANIC CALLED. UPON REACHING CRUISE, FLIGHT CREW NOTICED HOT BURNING ODOR; ACFT RTB FOUND WINDSHIELD HEAT CONTROL KNOB IN THE OPEN POSITION; CLOSED VALVE, OPS NORMAL ON SUBSEQUENT RUNS AND FLIGHT.