United Airlines flight UA-858 had to return and make an emergency landing at Shanghai Pudong International Airport, Shanghai, China, on February 14.
The Boeing 747-400, en-route to San Francisco, California, had to return due to an unusual odour in its cabin.
The plane landed uneventfully.
No one was injured.

Mesa Airlines flight YV-6259 had to return and make an emergency landing in Columbus, Ohio, on May 18th.

