Accident Details
On 3 January 2002 at 1702Z, a Piper PA34-200T aircraft registered ZS-JZR was conducting a private flight under Instrument Flight Rules from a farm aerodrome near Standerton to Pietermaritzburg Aerodrome. The weather conditions were Instrument Meteorological Conditions. On board were the pilot and three passengers. Approximately 17 minutes before the estimated time for the ORI beacon at Pietermaritzburg, the fuel flow for the left-hand engine decreased from about 12.6 gallons per hour to 8 gallons per hour. The pilot activated the auxiliary electric fuel pump to the "HIGH" setting and was able to keep the engine operating. During the final approach phase, the left-hand engine failed. The pilot performed a forced landing on school grounds approximately 1 nautical mile north of the aerodrome at coordinates S29°38.404' E030°23.532'. The aircraft sustained substantial damage, and one passenger was injured.
Background
The aircraft had a history of fuel flow defects with the left-hand engine prior to the accident flight. Two aircraft maintenance engineers attempted to rectify the defect but were unsuccessful; they did not identify a loose tube nut in the left-hand engine's fuel system. Apart from this defect, the aircraft was maintained according to the approved maintenance schedule. At the time of the accident, the airframe had accumulated 4288.73 hours. The last Mandatory Periodic Inspection was certified on 31 May 2001 at 4201.4 hours, and the aircraft had operated 87.33 hours since that inspection.
Probable Cause
The tube nut that was not properly tightened allowed air to enter the left-hand engine's fuel system, adversely affecting engine performance. The left-hand engine failed during the final approach due to an over-rich mixture condition with the auxiliary fuel pump operating on the "HIGH" setting. The aircraft could not maintain altitude in the landing configuration, and the pilot crash-landed on school grounds near the runway threshold.