What happened
On 16 February 2010, a private pilot was operating a Cessna 177 RG, registration ZS-MRD, on a flight from Lanseria Aerodrome to Heidelberg Aerodrome. While approaching Heidelberg, the pilot discovered that the aircraft's undercarriage would not extend.
After determining the gear was stuck, the pilot elected to return to Lanseria. Upon arrival, the pilot communicated the emergency to the tower and contacted the aircraft's maintenance organization via radio. In an attempt to deploy the gear, the pilot performed various maneuvers, including low-G movements, but the undercarriage remained retracted. The pilot noted that using the manual extension system was not feasible while flying solo.
Ultimately, the pilot executed a wheels-up landing on runway 0PG Right at Lanseria. The aircraft skidded for approximately 100 meters. While there were no injuries, the aircraft sustained damage to the propeller tips, the belly sheet metal, and the lower fuselage antenna.
The investigation
SACAA AIID investigators examined the aircraft and its maintenance history, finding that the aircraft was properly maintained and all required inspections had been performed according to the manufacturer's manual.
Technical examinations focused on the hydraulic landing gear system. A retraction test conducted at an approved maintenance organization, witnessed by the investigator, revealed that the eye-end rod had detached from the main gear actuator. Metallurgical analysis of the broken rod-end showed a fracture surface consistent with ductile overload. The investigation concluded that this specific component had likely failed due to a dynamic overload during a previous landing where the gear had not been fully extended.
Findings
- The primary cause of the landing gear failure was the breakage of the eye-end rod from the main gear actuator.
- The mechanical failure of the rod-end was attributed to dynamic overload from a prior landing event.
- The pilot did not utilize the manual gear extension system during the emergency.
- Weather conditions were clear and did not contribute to the incident.