Accident Summary
On 10 April 2025, at approximately 1507Z, a Jabiru SP aircraft (registration ZU-OIL) conducting a training flight under Part 141 experienced an engine stoppage and executed a forced landing on a field in Pumulani Agricultural Holdings, 3 nautical miles east of Wonderboom Aerodrome (FAWB), Gauteng. The aircraft sustained substantial damage when the nose gear collapsed during the rollout, causing it to nosed over and come to rest inverted. No injuries were reported.
Sequence of Events
The flight, with a flight instructor and a student pilot on board, departed FAWB for a local training flight. After about 30 minutes, the crew performed touch-and-go circuits on Runway 29. Shortly after rotation, the oil pressure indication decayed while oil temperature remained constant. The crew entered a right crosswind leg to monitor the situation. While turning right base leg, the engine ran rough and stopped. The instructor broadcast a Mayday call on FAWB tower frequency 118.35 MHz. Being 3 nautical miles from the threshold, the crew identified a field for a forced landing. The aircraft touched down on overgrown grass approximately 1 meter in height. About 20 meters after touchdown, the nose gear collapsed, and the aircraft nosed over.
Aircraft and Crew Information
The aircraft, a Jabiru SP (serial number 370), had accumulated 838.8 total airframe hours. The flight instructor held a valid Commercial Pilot Licence with 2,006.8 total hours, including 158.3 on type. The student pilot held a valid Student Pilot Licence with 15.4 total hours. Both pilots possessed valid medical certificates with no restrictions.
Investigation Findings
Examination revealed that the oil hose (part number PH089BN) connecting the oil filter to the oil cooler had burst, resulting in engine oil being pumped overboard. The hose was found to be a PVC type rated for a maximum temperature of 60°C, and its original equipment manufacturer stated it was not suitable for aircraft or vehicle applications. The hose had been replaced during the annual inspection certified on 3 November 2023, approximately 11.1 flight hours before the accident. Investigators noted that the hose was in close proximity (approximately 30 mm) to the exhaust assembly, and the heat sleeve fitted over the hose did not cover the area where it attached to the oil cooler, where the burst occurred. The approved person who certified the last annual inspection stated that the hose was purchased from a wholesale store specializing in hydraulic hoses.
Probable Cause
The aircraft nosed over during a forced landing on a field after the engine had stopped operating. The cause of engine stoppage was attributed to the oil hose (P/N: PH089BN) fitted between the oil filter and the oil cooler that burst, resulting in engine oil being pumped overboard and, ultimately, the engine stoppage.