A Japan-bound Vietnam Airlines jet made an emergency landing at a Hong Kong airport on Sunday as the ventilation system malfunctioned, the airline said on the same day.
Flight VN350 departed at 0:50 am on Sunday from Ho Chi Minh City for Fukuoka, carrying 184 passengers, the national flag carrier said.
The plane, an Airbus A321, urgently landed at 4:10 am local time in Hong Kong after the ventilation system was found not working properly, the carrier said.
Vietnam Airlines said it had placed the passengers on an alternative flight that landed in Fukuoka at 8:30 pm local time on Sunday.
Last December, a Vietnam Airlines plane encountered technical problems when it was carrying 135 passengers from HCMC to Vinh, the capital city of the north-central province of Nghe An.
The incident happened above Vinh Airport, leading to a sudden drop in cabin pressure. The pilots descended from 35,000 feet to 13,000 feet before making an emergency landing at Noi Bai International Airport in Hanoi to ensure the best possible ground support.
The seven-member flight crew, including Czech captain Pechanec Marek, was soon suspended pending a procedural investigation into the incident.
Nguyen Thanh Trung, a former deputy general director of Vietnam Airlines, told news website VnExpress that a drop in cabin pressure is typically caused by a leaky gasket.
Trung also said the pilots took the right course of action by asking for permission for its emergency landing at Noi Bai airport.