What happened
On September 12, 2002, a student pilot was conducting a solo navigation flight originating from Air Force Base Swartkosts. The intended route included stops at Warmbaths and Witbank, passing through the Pretoria General Flying Area No. 2, before returning to Swartkops. While flying toward the Rooiwal Powerstation, the engine of the Cessna A150L, registration ZS-IOP, failed. The pilot managed to execute a successful emergency landing on a tarred road located approximately 4nm northeast of Roodeplaat Dam. There were no injuries and the aircraft sustained no damage during the landing. The following day, after being refueled, the aircraft was flown to Wonderboom Airport without further incident.
The investigation
An investigation by the SACAA AIID established that the engine failure was the direct result of fuel exhaustion. The inquiry revealed a significant discrepancy between the aircraft's actual performance and its documented flight manual. Although the aircraft was approved with a flight manual for a Continental O-200 engine, it had actually been fitted with a more powerful 150HP Lycoming O-320 engine via a Supplemental Type Certificate (STC). Crucially, the necessary manual supplements for this engine upgrade had not been incorporated into the approved documentation.
Findings
- The increased fuel consumption of the Lycoming engine (6.5 to 7.5 US gallons per hour) compared to the standard Continental engine (4 to 5 US gallons per hour) significantly reduced the aircraft's endurance.
- The aircraft's standard fuel tanks provided insufficient reserves for the planned flight duration.
- Several maintenance issues were identified during the on-site inspection, including an air filter installed upside down, an unserviceable carburettor heat box, an oil leak, and an unserviceable exhaust muffler covering plate.
- The student pilot's technical examination had been based on the standard engine specifications rather than the actual engine installed.
- This incident followed a similar fuel exhaustion event involving the same aircraft just one day prior.
Safety action
Following the investigation, several corrective measures were implemented, including:
- Auditing the flight school to prevent recurrence.
- Addressing maintenance deficiencies with the Approved Maintenance Organisation (AMO).
- Investigating the CAA's flight manual approval process.
- Ensuring the necessary flight manual supplements were submitted and approved.
- Verifying the airworthiness of the aircraft through a full inspection.