Why and when did the narrator say that ‘everything’ was going well, it was an easy flight.’?

This excerpt is from the short story “Black Aeroplane”. Frederick Forsyth was the pilot who describes his strange flight experience he had in this story. The story is about a pilot who got lost in a dark cloud during his flight from Paris to London and was guided by a strange airplane that had appeared in the middle of that cloud.

The flight of old Dakota started in Paris and headed towards England. It was an easy flight, the sky was clear and the weather was fine. When it reached 150 km away from Paris, it suddenly confronted huge black storm clouds. It only had limited fuel to take him to England. He could go back to Paris but he decided to take the risk and go through the storm clouds because he wanted to spend the holiday with his family.