What happened
On the morning of 1 April 2013, the pilot of a Cessna 210 was one of a group intending to fly various light aircraft under the visual flight rules from Bullo River homestead to Emkaytee, a private airstrip near Darwin, Northern Territory. Low cloud delayed all of the departures from Bullo River and the aviation forecasts and weather radar images accessed by the group via the internet indicated isolated thunderstorms, low cloud, and rain in the intended area of operation. Some improvement was forecast after 1130 local time.
By lunchtime the weather had lifted at Bullo River and the pilots observed that the weather radar images were indicating an improvement en route. All of the pilots departed between 1300 and 1500, some electing to track via the coast and the rest tracking as required more or less on the direct track. The pilot of the Cessna 210 departed at about 1415 with three passengers to track via the coast.
The pilots in the group were communicating by radio on a discrete frequency and the Cessna 210 pilot was heard to report at about 1510 that he was approaching Cape Ford and the weather ahead was gloomy, or words to that effect. That was the last radio transmission from the pilot.
When the aircraft did not arrive at Emkaytee a search was initiated. Bodies and a small amount of wreckage were found on the southern shoreline of Anson Bay, about 10 km south-east of Cape Ford. There were no survivors.
What the ATSB found
During the flight from Bullo River to Emkaytee, the pilot continued to track along the planned coastal route towards a thunderstorm, probably encountering conditions such as low cloud, reduced visibility and turbulence, and as a result of one or more of those factors the aircraft descended and collided with water.
Safety message
Tracking visually via a coastal route in marginal weather conditions can be advantageous in terms of ease of navigation and absence of elevated terrain, but can also increase the risk of spatial disorientation in the context of drastically reduced visibility exacerbated by a lack of surface definition when over water.
In situations where significant weather is forecast or otherwise expected, pilots are encouraged to access the Bureau of Meteorology detailed weather briefings (via the phone number on the area forecast) to assist with understanding the conditions at the time as well as the immediate trend.