Has anyone been prepared for the possibility that unexpected poor visibility   will stop the pilot from landing? If your pilot is forced to turn back only for his lack of passing a certain test, you will be certainly shocked. This very thing happened to the passengers on Flight BE1431 on Thursday. Just minutes before landing on Charles de Gaulle Airport  , Paris, the pilot, a very experienced one, told his passengers, "Unfortunately I'm not qualified to land in Paris for the poor visibility. To do so a level II qualification is required, which I have not gained. We'll have to fly back." Then, you may guess how the passengers felt about their flight back to the starting airport.     A spokeswoman said the pilot was really experienced with more than 30 years flying a number of different passenger aircraft types. "But he has recently transferred from flying aBQ300 to aBQ400, so hehas to regain his qualification for landing in such conditions as the thick fog he experienced this time," she said. "The pilot, therefore, quite correctly turned the aircraft back, a decision 100 percent accepted by the aviation   officials in the company." One passenger said she had missed an appointment for an interview in prefix = st1 /Paris. "I might have had a nice chance to work inParis," she told the local newspaper. "The whole thing sounds hard to believe. If I had not been on the plane, I would take it as a funny story!" The British Civil Aviation Authority described the incident as one that was "quite unusual but probably not unheard of," because there are different classifications   of aircraft with different qualifications for landing in different climatic conditions and when an aircraft is updated, the pilots have to get retrained, even though they have enough skills to do the job successfully.  Poor pilot, it's not really his fault... According to the passage, it was   _   that mainly caused the aircraft to fly back.
the unusual thick fog the pilot's qualification the air traffic controller the airline company