Oriental Air Bridge flight OC-51 had to return and make an emergency landing in Nagasaki, Japan, on March 8th.
The plane took off for Tsushima, Japan, but had to turn back after white mist was noticed coming through air conditioning outlets.
The plane landed safely. There were 32 people aboard at the time; all of them remained unharmed.

JetBlue flight B6-1131 had to return and make an emergency landing in Charleston, South Carolina, on July 18th.
United Airlines flight UA-1219 had to divert and make an emergency landing in San Francisco, California, on January 14th.