The problem being that the flight was traveling from Nouakchott, Mauritania to Las Palmas in the Canary Islands: A relatively short jump. So they weren't carrying a full tank of fuel, and certainly not enough to reach Paris. Lemine turned around in his seat and told the hijacker this in French. He was met by a blank stare.
Now, it's important to note that, though Mauritania's official language is Arabic, it's still located in "French West Africa." Nearly everybody speaks French, except, of course, for this particular hijacker. And hey, that's understandable: Some of us barely speak the one language goodly. But remember his destination was Paris. France. He boarded a plane in a country where he did not speak the language, in order to hijack it to another country where he still did not speak the language. So just keep in mind that Abderraman is not exactly Lex Luthor here.
When the pilot realized this, he clicked on the intercom and told the plane the hijacker couldn't understand them, so they were going to make a hard landing at Las Palmas. If everybody braced themselves, the captain suggested, they might be able to use that opportunity to overpower the hijacker. When the plane touched down, Lemine immediately slammed on the brakes, the would-be hijacker was bowled over, and a flight attendant swooped into action, grabbing a pot of boiling water and hurling it into the off-balance criminal's face. Ten other passengers took the opportunity to beat the man to a pulp, and held him down until they came to a stop.