What happened
On 22 April 2002, a Cessna 402B, registered as ZS-OLI, was conducting a private flight from FASP in Botswana to Lanseria Airport (FALA). During the approach, the aircraft encountered an electrical malfunction. In response to the failure, the pilot utilized the emergency extension system to manually deploy the landing gear. However, as the aircraft touched down on runway 06L, the undercarriage collapsed. There were five people on board the aircraft at the time of the incident, and no injuries were reported.
The investigation
SACAA AIID investigators examined the mechanical and electrical systems of the aircraft to determine the sequence of events leading to the gear collapse. The investigation focused on the functionality of the emergency extension system and the nature of the initial electrical failure. The inspection confirmed that the aircraft sustained damage to the propeller, the undercarriage, and the lower portion of the fuselage.
Findings
- The primary electrical malfunction was traced to a faulty right-hand starter relay.
- While the pilot successfully deployed the gear via the manual emergency system, the investigation could not determine why the undercarriage failed to lock in the down position.
- Meteorological conditions at the time of landing were clear with good visibility (CAVOK) and a light 8-knot northeasterly wind.