A 19-year-old man from the northern province of Quang Ninh has been banned from domestic and international flights for nine months after refusing to pay a fine of VND4 million ($172) for smoking in a toilet on a VietJet flight from Hanoi to HCMC in March.
The Civil Aviation Administration of Vietnam said he ignored several reminders.
Passengers are always warned against smoking on flights, but this does not prevent some from trying their luck in toilets where clear no-smoking signs are posted.
A 28-year-old man from the northern province of Ha Giang also received a nine-month ban for failing to pay a fine of VND15 million. He had opened an exit door near his seat on a Bamboo Airways flight from Hanoi to HCMC on April 30, releasing the evacuation slide. It caused the flight to be delayed for several hours.
The four others had been caught using fake identity papers to go through airport security and have received a one-year ban.