Incident Overview
On 8 June 2002, at approximately 1130Z, a Cessna 402B registered as ZS-ALV was conducting a private flight from Wonderboom aerodrome. The aircraft was occupied by its new owner, who was not yet type-rated, and an instructor. The purpose of the flight was to familiarize the owner with the aircraft in the General Flying Training Area north of Wonderboom.
Flight Sequence
During the training session, the pilot executed steep turns and stalls at various flap configurations with the landing gear extended. Subsequently, the aircraft proceeded to Freeway aerodrome where two touch-and-go landings were performed on Runway 20. The aircraft was then repositioned for touch-and-go landings on Runway 02.
Accident Details
During the second touch-and-go landing on Runway 02, with full flap selected, the right-hand main landing gear collapsed approximately 120 feet after touchdown. The aircraft veered to the right and came to rest adjacent to the runway, oriented approximately 155° magnetic. Damage was sustained to the right-hand propeller and wingtip. No injuries occurred among the two occupants. The pilot reported that the landing gear indicators showed three green lights prior to landing and that the gear warning horn did not sound.
Investigation Findings
The South African Civil Aviation Authority (SACAA) investigated the accident. Metallurgical analysis of the failed landing gear components revealed no pre-existing failures or prior defects; all failures were attributed to an overload condition. The investigation concluded that the right-hand main gear collapsed because the side braces were not driven into the fully extended over-centre position prior to landing. This was believed to result from improper or poor rigging of the landing gear system, which prevented the bellcrank from moving the side braces into the locked over-centre position when the gear was selected down.