What happened
On 4 February 2021, two Air Tractor AT-502B aircraft, registered ZS-XAT and ZS-XAS, departed Lanseria International Airport for a ferry flight to Hosea Kutako International Airport in Namibia. The flight was being conducted under visual flight rules (VFR).
During the transit, the pilot of the second aircraft, ZS-XAS, encountered deteriorating weather and decided to return to Lanseria after consulting with Johannesburg Information. However, the pilot of ZS-XAT became lost to communication. Tracking data showed that ZS-XAT climbed to over 10,000 feet before suddenly disappearing from radar and tracking systems near Morningside Airfield. An eyewitness reported seeing the aircraft emerge from clouds in a descending path, followed by a loud bang and smoke. The wreckage was later located at Letsatsi Game Lodge, where the pilot had died upon impact.
The investigation
SACAA AIID investigators examined the wreckage and flight data, establishing that the aircraft suffered an in-flight breakup. The investigation found that the aircraft had exceeded its maximum structural cruising speed in turbulent air, leading to a high degree of disintegration. Evidence showed the aircraft entered a left spiral, with various components, including wing stingers and flaps, severing and falling along the flight path before the final impact. The aircraft was destroyed by the force of the crash and a subsequent fire.
Findings
- The pilot was flying under VFR but entered instrument meteorological conditions (IMC) characterized by low-level clouds and light rain.
- The pilot was not instrument rated.
- The aircraft was airworthy and had undergone a recent mandatory periodic inspection.
- Spatial disorientation caused the pilot to lose control of the aircraft once visibility was lost.
- The aircraft was traveling at a speed that surpassed its structural limits during the descent.