A Vietjet aircraft prepares to land at Tan Son Nhat International Airport in Ho Chi Minh City in June 2020. (Photo: VnExpress)

The budget carrier, owned by billionaire Nguyen Thi Phuong Thao, has joined the list along with Emirati low-cost airline Air Arabia, the US's Frontier Airlines and JetBlue, as well as Australia's Jetstar.
The ranking was drawn up by Australia-based AirlineRatings.com, which monitors 385 carriers and takes into account audits from aviation governing bodies, government audits, airline crash and serious incident records, fleet age, along with pilot training and culture.