What happened
On September 18, 2001, a Cessna 310, registered as ZS-EVK, departed from Grand Central Airport for a flight to Ellisras. Shortly after takeoff, while the pilot was retracting the landing gear, a loud bang was heard within the cockpit. Following this sound, the pilot attempted to redeploy the undercarriage using both the standard and manual extension systems, but the nose gear failed to reach and lock in the down position.
During a subsequent fly-past, air traffic control visually confirmed that the nose undercarriage remained partially extended. As the aircraft returned to Grand Central Airport to land, the nose gear collapsed during the landing roll. There were two people on board the aircraft, and no injuries were reported.
The investigation
Investigators examined the mechanical state of the landing gear and conducted metallurgical analysis on the components. The investigation focused on the integrity of the retraction system and the specific point of failure within the undercarriage mechanism. \n## Findings
Technical examinations revealed that the bell-crank within the undercarriage retraction system had fractured. Metallurgical testing determined that this fracture was the result of a single overload condition. The analysis found no evidence of fatigue or any pre-existing defects that would have contributed to the structural failure. It is believed that the component was likely subjected to an abnormal landing or an improper gear configuration in a previous flight, which ultimately led to the fracture during the takeoff sequence of this occurrence.