What happened
On 29 March 2023, a Van's Aircraft, RV-8, registration ZU-WDN, was conducting a private flight from Gariep Dam Aerodrome to Potchefstroom Aerodrome. The pilot, an experienced airline training captain, was transporting the aircraft to a maintenance organization for its first annual inspection since its kit construction.
As the aircraft approached Potchefstroom for landing on Runway 03, the pilot encountered a strong wind from the northwest, estimated at 12 knots with gusts up to 15 knots. Following touchdown, the aircraft was struck by a left-hand crosswind, causing it to veer toward the right side of the runway. Despite attempts to maintain directional control, the aircraft departed the paved surface approximately 500m from the runway threshold. The aircraft then underwent a ground loop, resulting in substantial damage to the airframe, including a collapsed left main gear, a bent wing spar, and a detached tail wheel. No injuries were reported for the two occupants.
The investigation
SACAA AIID investigators examined the aircraft's maintenance history, the pilot's credentials, and local meteorological conditions. The investigation confirmed that the pilot was properly licensed and medically fit, holding an ATPL with significant total flying experience, though only 23 hours on this specific type. The aircraft was found to be airworthy and had a valid Authority to Fly at the time of the incident.
Meteorological analysis revealed a significant wind shift at the aerodrome. While automated reports showed lighter winds, the pilot's assessment indicated a substantial 14-knot crosswind component. Investigators also noted that the specific layout of hangars at Potchefstroom Aerodrome can create a funneling effect, intensifying winds when blowing from the northwest.
Findings
- The primary cause of the accident was the pilot overcompensating with opposite rudder when encountering a crosswind from the left, which led to the loss of directional control.
- A significant crosswind component of approximately 14 knots contributed to the excursion.
- The pilot's lack of familiarity with the specific environmental wind patterns at Potchefstroom Aerodrome played a role.
- The pilot had relatively limited recent experience operating conventional stick-and-rudder aircraft in the months leading up to the flight.