What happened
On 18 November 2003, a Cessna 402B, registration ZS-NLU, was conducting a training flight departing from Rand Aerodrome. The flight crew, which included an instructor, a student pilot undergoing type conversion, and a camera operator, had been performing aerial photography over the Sandton area before moving to the Johannesburg General Flying Area for maneuvers including stalls and simulated engine failures.
During the return to Rand Aerodrome, the pilot successfully completed a touch-and-go landing on Runway 29. However, during a subsequent landing attempt, the aircraft bounced. In an effort to prevent a heavy landing, the instructor took control and applied full power to initiate a go-around. During this maneuver, the left-hand engine experienced a lag, which caused the aircraft to veer left and depart the runway onto the grass.
The aircraft traveled approximately 250 meters on the grass with the nose wheel remaining airborne. As the instructor lowered the nose, the aircraft continued to roll for another 50 meters, at which point the nose wheel separated from the nose gear oleo fork. The excursion resulted in damage to the nose landing gear doors and both propellers contacting the ground. There were no injuries to the three occupants.
The investigation
Investigators examined the sequence of events following the engine performance issue and the subsequent mechanical failure. The investigation focused on the loss of directional control during the go-around and the structural failure of the nose landing gear during the excursion.
Findings
- The primary cause of the excursion was the left-hand engine lagging during the attempted go-around, which led to a loss of directional control.
- The aircraft veered off the runway and rolled for a total distance exceeding 300 meters on the grass surface.
- A critical mechanical finding was that the nose wheel retaining bolt-end nut was missing, which directly contributed to the nose wheel separating from the landing gear assembly after the aircraft entered the grass.