Report Raises New Doubts About Air Traffic System

The safety of the airport's new air traffic control system has again been called into question, after a new investigative report found that planes came too close to each other on 17 occasions in local airspace last year, up from 10 in 2016.

News agency Factwire obtained the official data showing the jump in what's officially called "loss of separation" cases.

That's when aircraft come within five nautical miles (9.2km) of each other horizontally, or one thousand feet vertically (300 metre) – the safe distance as set out by the International Civil Aviation Organisation.

The 17 such cases last year represented a six-year high, and came during the first year of the use of the problem-plagued AutoTrac III system.

That's up from ten incidents under the old air traffic control system in 2016.

FactWire also reported that there were 12 other cases classified as “minor technical incidents” last year – where planes came only momentarily too close to each other. It says this is three to four times higher than the number of incidents in the previous three years.

And in the first three months of 2018, the agency reports that there have already been two "loss of separation" cases and four "minor technical incidents".

FactWire also quoted an unnamed air traffic controller as saying that Hong Kong airspace has become “very unsafe”.

Responding to the latest report, the Civil Aviation Department said losses of separation could arise from a number of factors, such as bad weather, operating procedures and human factors.

But it added that alerts were issued to the affected aircraft in a timely manner, and that it would investigate every incident according to established procedures and make the necessary improvements.