A passenger on the Air Canada flight in which a young Asian man boarded disguised as an elderly man last month says she tried to warn the crew about the mask but was rebuffed.
Nuray Kurtur-Balas said she approached three flight attendants before take-off from Hong Kong, but nothing was done.
"I thought he was going to harm the plane," Kurtur-Balas, 35, told CNN. "I kept my iPhone in my pocket to call my family if something happened."
Officials said the man apparently boarded the plane wearing the mask and removed the disguise during a trip to the plane's restroom while it was in flight.