What happened
On 18 June 2022, a private flight operating under Part 91 regulations transitioned from Nelspruit Aerodrome to Rietfontein Airstrip in Mpumalanga province. The flight was conducted during the day under clear visual meteorological conditions. As the pilot approached Runway 03, the aircraft, a Sling 4 with registration ZU-INW, was configured with 20 degrees of flaps at a speed of 50 knots.
Upon touchdown, the main landing gear made contact with the runway at approximately 45 knots. The aircraft subsequently bounced twice before the nose landing gear struck the ground. The impact caused the nose gear to break off, forcing the nose section downward and causing the propeller to strike the runway surface. The aircraft then skidded for roughly 15 metres. While the aircraft sustained substantial damage to the propeller, engine cowlings, nose section sheet metal, and the nose gear, the pilot escaped without injury.
The investigation
SACAA AIID examined the circumstances surrounding the landing and the pilot's recent flight history. The investigation established that the pilot had recently returned to flying after a 38-year hiatus, having accumulated only 126 total flying hours, with only 4 hours specifically on the Sling 4 type.
Technical reviews confirmed the aircraft's maintenance status was current, with a valid Certificate of Release to Service and a valid Authority to Fly. Weather conditions at the time of the accident were favorable, featuring clear visibility and light north-westerly winds at 8 knots. The investigation also noted that the manufacturer's handbook specifies a stall speed limitation of 48 knots in the landing configuration and recommends an approach speed of 70 KIAS at 50 feet above ground level.
Findings
- The primary cause of the accident was that the approach speed was too low, leading to a stall.
- This loss of lift caused the aircraft to drop or lose altitude before the subsequent bounces occurred.
- The aircraft was noted to be unstable during the approach phase.