A mid-flight engine failure forced an Air France A380 jet with more than 500 passengers on board to turn back to the Ivory Coast capital Abidjan where it landed without further incident early Sunday.We were flying over Niger (to Paris)... I saw a ball of flame for a few seconds and then a large bang on the left side of the aircraft, Baudelaire Mieu, a journalist with Bloomberg News, told AFP.The plane began to roll, everything was shaking and people started to panic. The pilot came on and said We have just lost a left side engine. We are returning to Abidjan, Mieu said.The Air France-KLM manager for West Africa Jean-Luc Mevellec confirmed the incident.Technically, it is what is called an engine blow-out. It is a well-known problem, Mevellec told AFP.It happens from time to time. It is a well-known phenomenon, well understood and crew are well trained on simulators all year long to deal with this type of fault, he added.Mieu said the giant four-engined aircraft, the worlds biggest passenger jet, continued to vibrate all the way back to Abidjan. People were praying.It was a close call. I have never been so frightened!