Singapore Airlines flight SQ-958 made an emergency landing in Singapore, on April 21st.
The plane, heading to Jakarta, Indonesia, had to return after the passenger oxygen masks deployed without any obvious reason.
The plane landed safely. There were 113 passengers and 12 crew members aboard at the time; all of them remained unhurt.

GoAir flight G8-101 had to return and make an emergency landing in Kolkata, India, on June 7th.
British Airways flight BA-1468 made an emergency landing at Heathrow Airport, England, on January 15th.
Flybe flight BE-848 had to return and make an emergency landing in Edinburgh, Scotland, on February 16th.