What happened
On 15 February 2013, the crew of a Super Puma helicopter (VH-BHK) was returning to Barrow Island after conducting some night deck landing practice to an offshore vessel. At about halfway the helicopter entered cloud with severe turbulence and lightning. The crew steered away from Barrow Island and descended to the lowest safe altitude to try and escape the conditions, but after 10 minutes turned back towards the island.
With insufficient fuel to divert to a suitable night landing alternate or to safely conduct a published instrument approach, the crew of the twin-engine helicopter were compelled to shut down an engine to conserve fuel and to descend below the lowest safe altitude in instrument meteorological conditions. The crew eventually descended to 250 ft over water and visual contact was made with lights in vicinity of the island. To minimise distraction and conserve fuel, the crew did not restart the engine and landed in winds gusting to 50 kt. Fuel remaining was 300 lb (170 L), which was less than the stipulated fixed reserve.
What the ATSB found
The ATSB found that the crew departed Barrow Island for the night training flight with sufficient fuel to return and land with standard reserves intact as allowed by the aerodrome forecast, but encountered unforecast severe weather on the return sector that prevented a routine visual or instrument approach.
The validity of the Barrow Island aerodrome forecast had been extended to cover the duration of the flight, but the forecast did not include any reference to severe weather, and was not amended when the adverse trend became evident because the forecaster on duty at the time was unaware of the extended validity.
What's been done as a result
The Bureau of Meteorology compiled a report of the meteorological aspects of the occurrence which recommended the development of a handover checklist to be followed by all forecasters, including the handover of any non-routine forecasts. The report also recommended that all forecasters read the report and sign a reading register to indicate understanding of the importance of handing over critical information.
Safety message
Although a flight plan notification was not required and might not have made a difference in this occurrence, the non-submittal of an instrument flight rules notification to air traffic services was a missed opportunity to receive directed weather hazard alerts and reduce weather-related risk.