A United Airlines passenger plane heading to Shanghai from Los Angeles (LA) returned to the airport due to the captain forgetting his passport.

The flight path of United Airlines UA198, which returned from Los Angeles, USA, to Shanghai. /Courtesy of Baidu

According to CNN and other reports on the 24th (local time), United Airlines flight UA198, which was heading to Shanghai from Los Angeles, made an emergency return to San Francisco on the 22nd.

The reason for the return was that the captain had not taken his passport. The aircraft had 257 passengers and 13 crew members on board. It landed at San Francisco International Airport around 4:51 p.m. on the 22nd, three hours after departure.

One passenger noted to the Chinese media outlet Jimu News, 'After already flying for about two hours, there was an announcement that the captain had forgotten his passport.'

The airline explained to CNN that 'passengers were provided with meal vouchers worth $30 (about 44,000 won) that could be used at San Francisco airport.'

Passengers reportedly boarded another flight to Shanghai operated by a different captain after waiting approximately three hours at the airport.