As a major retrieval operation gets underway in the Atlantic Ocean for the wreckage of Flight 447, French investigators have warned they are not highly optimistic about the chances of finding its black boxes.Outlining a long and difficult enquiry into the crash of the Air France jet that went down with 228 people on board, the air safety team said it would not hide anything from journalists. “Whatever the implications, whatever we find, however disturbing it might turn out to be – we will say it,” said Paul-Louis Arslanian, head of the French civil aviation ministry’s bureau of investigation. “We will say it with simple words. We will try to avoid technical language.” The debris field – five kilometres long, between the islands of Fernando de Noronha and Sao Pedro and Sao Paulo, is in the middle of the Atlantic. A French research ship, the Pourquoi Pas, is on its way to the disaster zone. But it will take over a week to get there. It is carrying mini-submarines capable of going thousands of metres deep in the water. French military air crews were also travelling to the area. The Air France Airbus A330 went missing early on Monday in bad weather. It was travelling from Rio de Janeiro to Paris. People from more than 30 nations were on board.