What happened
On 26 October 2010, at approximately 1530Z, a midair collision occurred at Wonderboom Aerodrome (FAWB) involving two aircraft engaged in circuit operations. The first aircraft, a Piper PA-28-180 with registration ZS-KIN, was being operated solo by a student pilot performing circuit training. The second aircraft, a Jabiru SK registered as ZU-XBA, was being flown by a flight instructor and a private pilot conducting a revalidation check-flight.
At the time of the incident, the aerodrome was experiencing heavy traffic, with seven aircraft active on the frequency. The student pilot in ZS-KIN had recently completed several circuits under supervision and was cleared to follow ZU-BXA on final approach for Runway 29. However, during the approach, the student pilot failed to execute an instructed go-around. Shortly after ZU-BXA became airborne following a touch-and-go landing, it struck ZS-KIN from below at an altitude of approximately 30 feet. Both aircraft lost control and impacted the runway surface, causing significant damage to both airframes and a runway light.
The investigation
The SACAA AIID investigation examined the flight paths, air traffic control (ATC) communications, and the operational environment. The inquiry reviewed the student pilot's recent training, noting that while he had been assessed as competent for solo flight, he lacked significant experience. The investigation also scrutinized the ATC workload, noting that the controller was managing a high volume of traffic alone at the time of the accident. Furthermore, the investigation looked into the decision-making processes of the Aviation Training Organisation (ATO) regarding the student's solo flight during a period of heavy circuit congestion.
Findings
- The primary cause of the collision was the failure of the student pilot in ZS-KIN to execute an immediate go-around as directed by ATC.
- The student pilot experienced a loss of situational awareness and failed to observe ZU-BXA in time to avoid the collision.
- The crew of ZU-BXA also failed to identify ZS-KIN sufficiently early to take evasive action.
- ATC instructions to the student pilot were not sufficiently assertive to ensure a timely reaction during a critical phase of flight.
- The student pilot's failure to respond to the first three radio calls from ATC contributed to the breakdown in separation.
- The decision by the ATO to permit solo flight for a student pilot during a period of high traffic density placed the pilot in an overwhelming workload environment.
- The air traffic controller was operating under a high workload with no immediate assistance in the tower.
Safety action
- The investigation identified that the ATO's decision to allow solo flight during heavy traffic was a significant contributory factor, noting a disregard for safe operating procedures regarding workload management.