Drone encounter - Are "isolated cases" not dangerous? - Carl Lewis

Cathay plane's near miss with 'intruder' aircraft in mainland China airspace

Automatic collision avoidance warning was not triggered in 2013 incident, the airline reported

A Cathay Pacific aircraft narrowly avoided a collision with a military aircraft in mainland airspace in 2013, it has emerged.

Pilots had sight of the "intruder" aircraft, understood to be a drone, but the automatic aircraft collision avoidance warning was not triggered, the airline disclosed. The airline later reported the incident to Hong Kong's aviation regulator, which concluded it was an "isolated" case.

For the Hong Kong-based carrier operating in increasingly crowded mainland skies, the "near miss" was a close call. It was one of eight "high-risk" incidents disclosed by the airline that occurred in 2013. One involved the collapse of an air bridge at Hong Kong International Airport.

A Cathay spokeswoman said: "There was a sighting of a small intruder aircraft - size similar to a glider - and there was no TCAS [traffic collision avoidance system] contact."

The incident was mentioned only in the airline's annual sustainability report for 2013.

Cathay Pacific maintains a target of zero accidents and zero "high-risk" incidents.

The airline's latest safety report for 2014 showed just one high-risk incident involving a lithium battery fire in a mail bag in a Singapore warehouse.

The Hong Kong aviation regulator, the Civil Aviation Department (CAD), launched its mandatory occurrence reporting (MOR) scheme in a bid to secure free and uninhibited reporting of aviation incidents in confidence on the principle that the reported information would be processed and used only to improve flight safety where applicable.

A spokeswoman for the department said: "Due to the need to maintain confidentiality and without the consent of the originator, we are not in a position to disclose the details of any reportable occurrence for other purposes.

"However, we can confirm that the event ... had been reported to CAD under the MOR scheme. The airline concerned had completed their investigation with relevant parties according to the requirements of CAD. CAD agreed that the occurrence was an isolated case."