Taiwan's largest airport on Thursday was checking its security measures after finding a woman sleeping on a parked aircraft, DPA reported.
"We will examine our security measures and will investigate how she made her way into the China Airlines jet," said Chao Heng-ti, a press officer for Taoyuan International Airport near Taipei.
She said airport police found the woman, who is in her 50s, sleeping Thursday in the pilots rest area next to the cockpit.
The woman carried no passport or plane ticket. Police took her to a hospital for evaluation because she seemed mentally disturbed.
Surveillance cameras showed the woman walking on the tarmac but the airport was investigating how she entered the plane, Chao said.
She said responsibility for the incident also rested with China Airlines, which, she said, should have placed the jet under guard because it was parked overnight at the airport.
Taiwan's largest airline said it was also perplexed about the incident because the jet was parked in the restricted area of the airport.