| Occurrence Briefs are concise reports that detail the facts surrounding a transport safety occurrence, as received in the initial notification and any follow-up enquiries. They provide an opportunity to share safety messages in the absence of an investigation. |
What happened
On the morning of 18 June 2019, the pilot of a de Havilland DHC-2 aircraft was conducting a charter flight with three passengers on board. The flight departed from Proserpine, Queensland and planned to land near the Great Barrier Reef before returning to Proserpine. During cruise, the pilot observed a thick, clear substance coating the windscreen but at the time believed it to be cleaning fluid.
As the aircraft approached the landing point, the pilot had trouble seeing the buoys in the water due to the substance and conducted a go-around. At this point, the pilot realised the substance was in fact engine oil and began conducting checks to ensure performance was not compromised, climbing the aircraft to 4,500 ft. The pilot checked the oil dipstick, noting the aircraft was losing oil at a low to moderate rate. Knowing that he had three litres of additional oil carried in the aircraft, he conducted a diversion to Shute Harbour, observing the engine gauges at all times. Once closer to the mainland, he added the remaining oil to the engine and landed without further incident at Shute Harbour.
Engineering Inspection
The engineering inspection revealed that two studs holding the no. 9 cylinder to the engine case were missing and multiple others were loose, resulting in oil spilling from the bottom of the cylinder. The operator advised that an engineering inspection was conducted four days prior to the incident, with no issues identified.
About this report
Decisions regarding whether to conduct an investigation, and the scope of an investigation, are based on many factors, including the level of safety benefit likely to be obtained from an investigation. For this occurrence, no investigation has been conducted and the ATSB did not verify the accuracy of the information. A brief description has been written using information supplied in the notification and any follow-up information in order to produce a short summary report, and allow for greater industry awareness of potential safety issues and possible safety actions.