What happened
On 10 November 2009, a private flight involving a Quicksilver microlight departed from Farm Kleinfontein in the Donkerhoek area of Gauteng. The flight, which included the pilot and one passenger, lasted approximately ten minutes before the aircraft began its approach to a runway located on a ridge.
During the final approach, at an altitude of roughly 180 feet, the engine suddenly failed. In an attempt to find a safe landing spot, the pilot maneuvered to the right of the ridge, pitching the aircraft nose-down to gain airspeed. However, the aircraft was too low to clear the terrain and struck the rocky ridge sideways. The impact caused a brief fire near the fuel supply hose, though it was extinguished quickly. Both the pilot and the passenger sustained serious back injuries and required hospitalization.
The investigation
Investigators from the SACAA AIID examined the wreckage and the aircraft's components. The investigation revealed that the aircraft had no official registration markings, and while the owner suggested the registration was ZS-VVW, no such record existed within the authority's files.
Technical examination of the fuel system showed that the aircraft was utilizing a 20-litre metal jerry-can as a fuel tank. This container was a standard vessel typically used for water or fuel, modified with a plastic tube to monitor fuel levels. The investigation focused on the mechanics of the engine failure and the condition of the fuel delivery system.
Findings
- The primary cause of the engine failure was fuel starvation caused by a vacuum forming inside the fuel tank.
- The metal jerry-can used as a fuel reservoir lacked a proper vent hole, preventing atmospheric pressure from equalizing.
- The aircraft's engine stopped because the lack of ventilation restricted the flow of fuel from the tank to the engine.
- The pilot was operating with an expired microlight pilot's licence.
- There was no evidence that the aircraft had undergone regular maintenance by an approved person or that it had undergone recent annual inspections.
Safety action
It was recommended that the Recreation Aviation Administration of South Africa (RAASA) investigate the circumstances surrounding the operation of an unregistered aircraft and the use of an invalid pilot's licence.