CATHAY Pacific is suing the city of Los Angeles in a bid to prevent it from tripling fees charged for jets landing at its international airport. The lawsuit accuses the city of unfairly trying to solve its budget problems on the backs of the airline industry. Cathay has joined forces with British Airways and Virgin Atlantic Airways, and 37 other airlines in the suit. City officials have reacted to the lawsuit with outrage. They have threatened that airlines will be barred from using the busy airport if they fail to pay the higher fees when the first bills become due on Tuesday.