British Airways flight BA-864 had to return and make an emergency landing at Heathrow Airport, England, on 
July 23rd.
The Airbus A320-200 plane took off for Warsaw, Poland, but had to turn back due to an unidentified odor onboard.
The plane landed safely. All passengers and crew members remained unharmed.
Click to view full size photo at Airliners.net
Contact photographer Alejandro Ruiz
What: LAN Airlines Airbus A319-100 en route from Concepcion to Santiago
Where: Concepcion
When: Dec 20th 2009
Who: pilot
Why: After takeoff, one of the pilots had an attack of appendicitis.
The flight returned to Concepcion and was cancelled. Passengers were booked on a later flight.
All Nippon Airways flight NH-273 had to return and make an emergency landing in Tokyo, Japan, on January 26th.
The Boeing 777-300 plane took off for Fukuoka, Japan, but had to turn back after the crew needed to shut down one of the engines.
The plane landed safely. All passengers and crew members remained unharmed.
Click to view full size photo at Airliners.net
Contact photographer Alevik
What: Air Canada Airbus A330-300 en route from Toronto to Montreal
Where: Montreal Canada
When: Sep 25th 2011
Who: 257 aboard, 9 injured
Why: On approach to Montreal, the Air Canada flight encountered turbulence.
Six members of the cabin crew were injured in the turbulence. Three passengers were injured.
On landing in Montreal, there was a 105 minute delay, after which the cabin crew could not work. Alternative crew members, presumably worked the next leg of the flight to Brussels
Air Baltic flight BT-9802 returned to Amsterdam, Netherlands, on December 24th.
The Boeing 737-500 plane took off for Riga, Latvia, but had to turn back after the crew failed to retract the landing gear.
The plane landed back safely. All passengers and crew members remained unharmed.
Qantas flight QF-566 had to return and make an emergency landing in Perth, Australia, on February 27th.
The Boeing 737-800 plane took off for Sydney, Australia, but had to turn back due to airspeed disagreement.
The plane landed safely. All one hundred and seventy-four people aboard remained unharmed.
Flydubai flight FZ-157 made an emergency landing in Beirut, Lebanon, on March 28th.
The Boeing 737-800 plane, flying from Dubai, United Arab Emirates, was preparing to land in Beirut when a bird hit it, prompting the crew to declare emergency.
The plane landed safely. Everyone aboard remained unhurt.