An Air China flight taking off from Hong Kong for Chengdu on Sunday night departed from its usual path and turned towards Lantau Island. It was ordered by air traffic control to immediately manoeuvre away due to hilly terrain ahead.
Flight CA428 managed to turn away from the mountainous island after passing above Tai O fishing village, and arrived safely in the western Chinese city.
Flight path tracking website Flightradar24 showed that the pilot made a left turn at an altitude of around 2,700 feet at 9:07pm, a minute after take-off.
“Air China flight 428, expedite climb, terrain ahead, terrain alert – expedite climb passing 5,000 feet – expedite,” an air traffic controller told the pilot in recordings obtained by Apple Daily.
Flights departing from Hong Kong usually do not make this turn until mid-way into the Pearl River Estuary, a long distance away from Lantau Island.
Lantau Peak – the highest peak at the centre of the island – rises to over 3,000 feet.
Making a sharp turn right after passing above Tai O at an altitude 3,600 feet, CA428 managed to revert to its original path. The flight landed in Chengdu at at 11:22pm.
“The biggest responsibility of a pilot is to ensure the safety of the flight,” wrote Hong Kong lawmaker and professional pilot Jeremy Tam on Facebook on Monday. He told local paper Ming Pao that the flight’s left turn was not authorised by air traffic control.
Tam told reporters on Monday he believed that the Civil Aviation Department would investigate whether there had been errors on the part of the pilot or the autopiloting system.
A Civil Aviation Department spokesperson told HKFP that the incident did not pose any threat to aviation or public safety. Air China will be requested to submit a report to the department, while the department has also notified mainland China’s Civil Aviation Administration of the incident.
“The Civil Aviation Department will continue to follow up on the incident and take necessary action,” the spokesman added.