Accident
On 29 April 1999, at 1400Z, a Cessna R182 aircraft registered A2-ADC was being taxied approximately 5 meters from a hangar at CNJ Aviation, Rand Airport, in preparation for a flight to Gaberone, Botswana. As the pilot maneuvered, the nose undercarriage suddenly collapsed. The pilot, the sole occupant, was not injured. The weather was fine with calm winds and a temperature of 24°C.
Investigation
The aircraft was recovered by an Aircraft Maintenance Organization at Rand Airport and placed on jacks. The nose undercarriage doors were found fully closed with the nose undercarriage retracted. Inspection of the undercarriage retract and extension system revealed no defects. The nose undercarriage was found retracted with the uplocks engaged, indicating the undercarriage selector lever had been in the UP position. Retraction and extension tests using both normal and emergency systems were performed, and the throttle and undercarriage warning systems functioned normally.
Probable Cause
The investigation determined that the pilot increased engine power for taxiing and made a sharp left turn. This caused the nose undercarriage oleo to extend sufficiently to interrupt the electrical continuity of the squat switch on the nose oleo, leading to the nose undercarriage retracting while the selector lever remained in the UP position.