What happened
On 19 May 2019, a Carl Babst Raven 1 aircraft, registration ZU-FBP, was involved in an accident during a type conversion training flight. The flight, which included a student pilot acting as the pilot flying and a flight instructor, departed from Rhino Park Aerodeome in Gauteng Province.
During the takeoff roll, the aircraft rotated approximately 150 metres from the runway threshold. Shortly after, the aircraft's nose pitched up uncontrollably, leading to a high angle of attack. This caused the aircraft to enter a stall, resulting in a crash onto the runway approximately 15 seconds after takeoff. The impact and subsequent fire destroyed the aircraft. The pilot flying sustained minor burns to the right hand, while the instructor suffered serious back injuries.
The investigation
An investigation by the SACAA AIID examined the wreckage and the circumstances leading to the loss of control. Investigators confirmed that the aircraft's mechanical systems, including the engine, propeller, and flight control continuity, were functioning normally prior to the accident.
The inquiry focused on a non-standard nylon rope that had been attached to the control stick and connected to the elevator. This rope was used to hold the stick in a rearward position to allow access to the floor-mounted brake lever during taxiing, and to keep the elevator in a fixed position while parked. The investigation established that the rope remained attached during the takeoff roll, which physically prevented the pilot from pushing the control stick forward to adjust the pitch.
Findings
- The primary cause of the accident was that the nylon rope remained connected to the control stick, which restricted the crew's ability to control the aircraft's pitch.
- The pilot flying admitted to forgetting to disconnect the rope before takeoff.
- The instructor also failed to verify that the rope had been removed during pre-flight checks.
- Because the rope prevented the forward movement of the control stick, the crew was unable to reduce the angle of attack to recover from the stall.
- The rope was not a standard part of the aircraft and was not included in the official pre-takeoff checklist.
Safety action
Following the accident, a safety message was issued recommending that flight crews perform thorough pre-flight inspections, specifically emphasizing the importance of comprehensive flight control checkouts prior to lining up for takeoff.