Background
Due to an industrial action suspending normal domestic airline services, a pilot hired the aircraft to transport passengers stranded by the strike between Hobart and Melbourne. The pilot submitted an Instrument Flight Rules (IFR) flight plan for the return flight to Melbourne, despite not holding an appropriate Instrument Rating. The flight to Melbourne was completed without incident. After refueling and boarding five passengers, the return flight commenced. Each passenger paid a fare, although the pilot did not hold a Charter Licence or an appropriate pilot licence.
Flight to Hobart
At the time of the return flight, considerable cloud was present near Hobart Airport. At 1800 hours, the recorded cloud cover was one okta stratus with base 800 feet, five oktas stratocumulus with base 3000 feet, and five oktas altocumulus with base 11,000 feet. The surface wind was light westerly, Runway 30 was in use, rain showers were in the area, and the runway was wet. Daylight ended at approximately 1748 hours.
When the pilot of VH-EXQ contacted Hobart Tower at approximately 1800 hours, he reported descending to 7000 feet and being 50 km from the airport. The Aerodrome Controller cleared the aircraft for further descent in stages to maintain vertical separation from a preceding aircraft.
Approach and Descent
Hobart Airport's only Instrument Landing System (ILS) approach was aligned with Runway 12, with a tailwind of only two or three knots. To expedite arrivals, the controller offered both pilots the option of a straight-in ILS approach to Runway 12 instead of a circling approach to the into-wind Runway 30. Both pilots accepted. At 1803 hours, the preceding aircraft was cleared for an ILS approach. The pilot of VH-EXQ was advised to expect the same clearance but was instructed to make one circuit of the holding pattern at Tea Tree Locator to ensure continued separation. The pilot misunderstood and, on reaching Tea Tree at about 1805 hours, continued towards the airport.
At 1807 hours, the controller cleared VH-EXQ for an ILS approach. The pilot acknowledged but did not advise that he had already commenced the approach. Descending towards the airport, the pilot maintained a high airspeed of nearly 200 knots. From overhead Tea Tree, he could see the preceding aircraft's lights and attempted to reduce speed to maintain separation, resulting in the aircraft being high on approach.
Engine Failure and Ditching
At 1810 hours, the controller asked if the pilot could land on Runway 12 or preferred an approach for Runway 30. The pilot chose Runway 30 and was cleared to a right base leg. The approach to Runway 12 was abandoned; the aircraft turned left onto a close right downwind leg for Runway 30. The landing gear and flaps (set at 1/4 down) were not moved. The pilot reported moving the throttles forward to increase power and maintain height; the aircraft yawed slightly right. Both propeller levers were pushed fully forward, both throttles fully opened, and mixture controls checked full rich. The aircraft again swung right. Identifying this as a right engine failure, and after checking the right propeller tachometer at about 1500 RPM, the pilot feathered the right propeller and selected landing gear and flaps up. He reported carrying out the feathering at about 300 feet and 100 knots. The aircraft was heading southwest toward Single Hill (elevation 680 feet) on the shore of Frederick Henry Bay. The pilot reported the aircraft would not maintain height or airspeed and turned left to avoid the hill. Wings were held level until touchdown in the bay.
Rescue Efforts
The controller, observing the aircraft turn right onto a close base leg then straighten on a southwesterly heading, asked the pilot to confirm tracking for Runway 30. The pilot did not answer; the controller called again. The pilot then reported trouble with the right engine and intent to feather, as the aircraft approached Single Hill before turning left and descending from view. No further transmissions were received. The Distress Phase of Search and Rescue was declared at 1815 hours. Emergency services, including a standby helicopter, were alerted. All six occupants were rescued as the aircraft sank and was lost.
Investigation Findings
The probable cause of the accident was that, following an apparent loss of power by the right engine, the pilot did not operate the aircraft in the configuration and at the airspeed necessary for safe single-engine flight. The pilot's responses may have been influenced by operating under Instrument Flight Rules conditions, for which he was not qualified. The cause of the reported loss of power by the right engine was not determined. The investigation discovered the following defects: general mechanical wear in the left engine, the left engine fuel injector system outside manufacturer's specifications, and a slight timing fault in one magneto on the right engine.