A file photo of a Vietnam Airlines aircraft. Photo: Ngoc Thang
A Vietnam Airlines aircraft bound for Ho Chi Minh City had to return to Hanoi's Noi Bai Airport around 40 minutes after its departure, after losing cabin pressure on Friday morning, the national carrier said in a statement.
The incident, which released oxygen masks, left a flight attendant slightly injured, while all 137 passengers were safe and moved to the next flight, according to the statement.
It was not immediately clear why the pressure loss happened.
An unnamed senior official with the Northern Aviation Authority said in news website VnExpress that loss of cabin pressure is a "common" technical error, adding that the crew handled the incident in accordance with regulated procedures.
The Airbus A350 was put into operation in September last year and its last maintenance was on December 13.
Last month another Airbus A350 aircraft of Vietnam Airlines was grounded in Paris for a few days following technical issues discovered prior to its scheduled flight.