Incident Overview
Shortly after departure, a flight instructor and his student became cold. The heater control was not in its usual position on the instrument panel, as both pilots were accustomed to flying later model Cessna 172s. The student located a white knob but could not read the nomenclature plate. Believing it was the heater control, he pulled the knob.
Loss of Engine Power
Approximately 1.5 hours later, the engine lost power. The instructor assumed control of the airplane and turned towards a private airstrip about 2 miles away. He instructed the student to make emergency radio calls and attempt to restart the engine. Strong headwinds prevented the airplane from gliding to the runway. The airplane stalled and impacted terrain. The airplane had been aloft for 1.7 hours when the engine lost power.
Postaccident Inspection
Postaccident inspection revealed that the student had inadvertently pulled the fuel strainer control knob instead of the cabin heat control knob. There were no fuel stains on the bottom of the airplane. The fuel strainer control is spring-loaded to the CLOSED position. Examination disclosed that the spring was missing.
Maintenance History
According to the Cessna 172F SERVICING INTERVALS CHECKLIST, the fuel strainer should be disassembled and cleaned every 100 hours. The last 100-hour inspection performed on N8389U was on December 14, 2000, 85.67 hours before the accident.