Executive summary
On 30 December 2009, an Aerospatiale-Alenia ATR 72-212A (ATR 72) aeroplane flying between Christchurch and Wellington encountered severe turbulence when about 50 nm north of Christchurch. Approximately 35 minutes later, another ATR 72 aeroplane, also flying from Christchurch to Wellington, encountered severe turbulence in the same general area.
Although no injuries or damage resulted from these incidents, the Transport Accident Investigation Commission (the Commission) decided to inquire into the adequacy of the meteorological information available to the pilots before and during the flights, the operator and flight crew action taken to minimise the risks of severe turbulence encounters, and the processes followed by the providers of air traffic and meteorological services in response to pilot reports of significant weather hazards.
The investigation found that the events might have been avoided or been less severe had the operator had a more robust flight dispatch system, and had the air traffic service complied fully with a requirement to pass flight information to pilots on first contact. The Commission made a safety recommendation regarding the clarity of information about hazardous meteorological conditions.
Related Recommendations
The interpretation of SIGMETs could be improved by the use of clearer reference to geographical regions, although the requirement to conform to ICAO Standards and Recommended Procedures is appreciated.