What happened
On 29 April 1999, a Cessna R182, registration A2-ADC, was preparing for a flight from Rand Airport to Gaborone, Botswana. During the initial stages of the flight, the pilot taxied the aircraft approximately five meters away from the CNJ Aviation hangar. While maneuvering the aircraft, the nose undercarriage suddenly collapsed. There were no injuries or fatalities resulting from the incident, and the weather conditions at the time were reported as fine with calm winds.
The investigation
Following the incident, an aircraft maintenance organization recovered the Cessable R182 and placed it on jacks for a detailed inspection. Investigators discovered that the nose undercarriage doors were fully closed and the nose gear was in the retracted position. Upon examining the undercarriage retraction and extension systems, no mechanical defects were identified. Tests performed on both the normal and emergency extension systems, as well as the throttle and undercarriage warning systems, all functioned correctly and showed no abnormalities.
Findings
Detailed analysis revealed that the undercarriage selector lever had been left in the UP position. The investigation established that as the pilot increased power for taxiing and executed a sharp left turn, the nose undercarriage oleo strut extended significantly. This movement caused an interruption in the electrical continuity of the squat switch on the nose oleo. Because the gear selector was already set to the UP position, this electrical interruption triggered the automatic retraction of the nose undercarriage during the turn.