Serious Incident Involving Jabiru J430 ZU-NDP at Port St Johns

Incident Overview and Flight Details On the morning of 9 December 2021, a Jabiru J430 aircraft, registration ZU-NDP, departed Wings Park Aerodrome near East London, Eastern Cape, for Virginia Aerodrome (FAVG) in KwaZulu-Natal. The flight was a private operation conducted under visual flight rules (VFR) by day, in accordance with Part 94 of the Civil Aviation Regulations (CAR) 2011. The aircraft was carrying a pilot and one passenger. Approximately one hour into the flight, while 140 nautical miles from the destination and near Port St Johns, the engine lost power and subsequently stopped. The pilot selected a beach at Port St Johns for a forced landing. During the landing, the nose gear dug into the soft sand, bringing the aircraft to a stop. Both occupants were uninjured, and the aircraft sustained minor damage, including a bent nose landing gear suspension shaft. ## Aircraft and Maintenance History The Jabiru J430, serial number 353, was manufactured in 2007 and powered by a Jabiru 3300 engine (serial number 33A1194). At the time of the incident, the engine had accumulated 1,818.6 hours, with a time between overhaul (TBO) of 2,000 hours. The last annual inspection was performed on 7 April 2021 at 1,818.6 airframe hours. The aircraft was fitted with a two-bladed Jabiru 60x53 propeller. Post-incident examination revealed no visible damage to the propeller or nose gear, though the nose gear suspension shaft was found bent. The aircraft was recovered the following day and transported to the manufacturer’s facility for detailed examination. ## Investigation Findings The fractured crankshaft assembly was submitted to the University of Pretoria’s Laboratory for Microscopy & Microanalysis. Visual inspection and microscopic analysis revealed a fracture at the No. 1 Conrod Big End (BE) position. The fracture surface indicated a fatigue failure mode originating within the radii. Significant post-failure corrosion and high-temperature exposure were noted on the No. 1 BE journal. The investigation identified a discrepancy in the part numbers of the No. 1 Conrod BE bearing compared to the remaining BE bearings. The No. 1 bearing exhibited excessive wear and removal of the top tin layer, unlike the other bearings. Records indicated that the No. 1 Conrod BE bearing was replaced on 10 May 2017 with a part number (24JA07 8290) not recognized by the manufacturer. ## Probable Cause and Contributing Factors The probable cause of the incident was determined to be engine failure resulting from heat generated between the crankshaft and the big end conrod, leading to metal wear and a fatigue crack that caused the crankshaft to fail. This failure stopped the engine, necessitating a forced landing. A contributing factor was the installation of a No. 1 conrod bearing that was not a manufacturer-approved part. The pilot held a valid Private Pilot Licence with a Jabiru J430 endorsement, and the aircraft held a valid Authority to Fly. Weather conditions were fine and had no bearing on the incident.