What happened
On 29 December 2022, a Premier Aviation; Cullinan PA290E (registration ZT-WWR) was engaged in a surveillance mission at the Grootegeluk Mine in Lephalale, Limpopo. The operation was being conducted under beyond visual line of sight (BVLOS) regulations.
Earlier that morning, the pilot had completed a separate flight to measure mine pits, during which an error message appeared on the remote pilot station. To resolve this, the pilot disconnected the UAS from the station to download and clear the flight logs. Following this maintenance, the pilot replaced the battery and prepared the aircraft for a subsequent launch.
During the transition phase of the second flight, the pilot observed that the aircraft's wings were not properly connected. Shortly thereafter, the UAS began a rapid descent, impacting the ground approximately 280 metres from the launch site. The impact resulted in substantial damage to the aircraft, though no injuries were reported on the ground.
The investigation
SACAA AIID examined the operational and maintenance records of the flight. The investigation confirmed that the pilot held a valid Remote Pilot Licence and medical certificate, and the operator possessed a valid Operating Certificate for Class 4A BVLOS operations. The aircraft's maintenance was being performed by a certified technician, and the UAS had undergone a mandatory periodic inspection earlier that year.
Findings
- The primary cause of the accident was that the wings were not attached during the pre-flight inspection.
- This omission prevented the aircraft from generating sufficient lift, leading to the high-speed descent and subsequent crash.
- The incident was further contributed to by an improper pre-flight inspection procedure by the pilot.