Since opening in 1998, there have been 822 incidents of missed approaches, or "aborted landings", at Hong Kong International Airport, representing 0.14% of the 600,000 landings there, Secretary for Economic Development & Labour Stephen Ip says.

Mr Ip told legislators today that records show missed approaches are more frequent between March and September.

"About 37% of the missed approaches were related to windshear. Other factors included problems with the aircraft, low cloud, adverse weather and poor visibility," he said.

The Hong Kong Observatory monitors windshear and provides timely warnings to air-traffic controllers, who relay the information to pilots.

Together with the observatory, airlines and pilot associations, the department has formed a Windshear & Turbulence Warning System Working Group, which meets regularly to revise and improve windshear detection and forecast, and the mechanism of communicating windshear data.

Mr Ip said the light detection and ranging system is designed to detect windshear under rain-free conditions, whilst the terminal doppler weather radar and its network of wind sensors perform the detection function on rainy days.