What happened
On 21 August 2023, a flight training mission involving an instructor and a student pilot experienced a serious in-flight incident. The flight, operating under Part 1-41 regulations, began at Wonderboom Airport with a planned route including navigational exercises at Pilanesberg Airport and an ILS approach at Lanseria International Airport.
After successfully completing a touch-and-go landing at Lanseria, the Cessna C172, registration ZS-STP, began its climb back toward Wonderboom. While passing through approximately 6,500 feet, the engine experienced two surges before failing. The instructor took control of the aircraft and declared a MAYDAY to Johannesburg Radar. Although air traffic controllers vectored the aircraft for a priority landing on Runway 25, the aircraft was unable to reach the runway, touching down approximately 300 metres short of the threshold. There were 0 fatalities and 0 injuries, and the aircraft sustained no damage.
The investigation
SACAA AIID examined the circumstances leading to the engine stoppage. The investigation established that the aircraft had exhausted its usable fuel supply during the flight. While the student pilot had estimated a remaining endurance of approximately four hours based on a visual inspection of the tanks and flight logs, the actual fuel remaining was insufficient for the mission requirements.
Findings
- The engine failure and subsequent stoppage were caused by fuel exhaustion.
- The student pilot relied on a visual inspection of the fuel tanks rather than using a measuring stick to confirm the actual fuel quantity.
- The instructor pilot failed to independently verify the fuel levels prior to departure.
- The student pilot's estimate of fuel endurance was inaccurate, as they believed the previous flight had only consumed one hour of fuel.
Safety action
Following the incident, the operator implemented a "Red Tag" notice. This directive serves as a formal reminder to all students and instructors that fuel measuring sticks must be utilized to verify on-board fuel levels before every flight.