THAT THE CERTIFIED FLIGHT INSTRUCTOR'S (CFI) MISJUDGED APPROACH WHICH RESULTED IN A LONG LANDING, THE CFI'S IN-FLIGHT DECISION TO A GO-AROUND WITH PARTIAL POWER, AND THE FAILURE OF THE CFI TO MAINTAIN AIRCRAFT CONTROL IN THE INITIAL CLIMB SEGMENT OF THE PARTIAL POWER GO-AROUND RESULTING IN AN INADVERTENT STALL. CONTRIBUTING TO THE ACCIDENT WAS THE INADEQUATE MAINTENANCE INSPECTION PERFORMED BY THE OPERATOR'S MAINTENANCE MANAGEMENT PERSONNEL AFTER THE INITIAL STUCK VALVE DEFICIENCY AND THE DECISION OF THE CFI TO OPERATE THE AIRPLANE WITH A KNOWN DISCREPANCY.