What happened
On 13 February 2010, a Sling aircraft, registration ZU-TAF, departed Virginia Aerodrome for a series of scheduled spin certification tests. The flight, operated by The Airplane Factory (PTY) LTD, involved two experienced test pilots performing a sequence of maneuvers including stalls and various degrees of rotational spins.
While performing a two-and-a-half-turn (900°) spin to the right, the aircraft's rotational velocity increased significantly. The pilot-in-command attempted to apply conventional recovery techniques, but the crew soon realized they had lost elevator control. The aircraft transitioned into an unrecoverable flat spin.
At approximately 4000 ft AMSL, the pilot attempted to deploy the aircraft's ballistic parachute. Although the deployment rocket fired with a loud report, the parachute failed to exit the fuselage and remained trapped in the nose section. Following emergency protocols, the pilots prepared to exit the aircraft. At roughly 2500 ft AGL, the crew initiated a bailout. The second pilot exited first, followed by the pilot-in-command, who sustained a fractured C2 vertebra when the canopy struck his leg during egress. Both pilots landed safely on a nearby beach, but the aircraft continued its descent and crashed into the sea near Tinley Manor. The wreckage was not recovered.
The investigation
SACAA AIID examined the flight sequence, maintenance records, and the mechanical performance of the emergency systems. The investigation confirmed that the pilots were properly licensed and that the aircraft had undergone its annual inspection only nine days prior to the accident.
Investigators analyzed the failure of the ballistic parachute, noting that the rocket had successfully fired but the parachute remained stuck in the nose. The investigation also reviewed the flight test program, noting that while a safety program existed, it had not been submitted to or approved by the SACAA for this specific flight. Additionally, the investigation looked into the canopy mechanism, which failed to remain in the open position during the bailout.
Findings
- The primary cause of the accident was the aircraft entering an unrecoverable flat spin during a high-rotation maneuver.
- The ballistic parachute failed to deploy because it remained trapped within the nose section of the aircraft, a failure attributed to an inadequate design.
- The pilot-in-command sustained a serious neck injury due to the canopy striking him while exiting the aircraft.
- The manufacturer had not obtained formal authorization from the SACAA to conduct these specific spin tests.
- The aircraft's wreckage could not be examined as it was lost at sea.