CHARLOTTE ( TheStreet) -- Jerry Orr, longtime director of Charlotte/Douglas International Airport, complained for years that hub carrier US Airways ( LCC) favored Pittsburgh over Charlotte. Things have changed. Charlotte/Douglas is among the country's fastest- growing airports. This month, it added flights to Rio and Honolulu, and US Airways said Rome service will begin in May. Charlotte currently has 552 daily departures to 127 destinations. Through September, it was the 11th busiest U.S. airport, according to Airports Council International. Pittsburgh International Airport, meanwhile, is fading out of the picture for US Airways. Today, the carrier operates just 46 daily flights to 11 destinations at the airport. Before the 9/11 terrorist attacks accelerated a steep decline in air travel, US Airways operated its biggest hub in Pittsburgh, with 550 daily departures to 110 destinations. Cost is a key reason the two airports seem headed in opposite directions. Charlotte/Douglas charges US Airways just 76 cents per passenger, likely the lowest rate anywhere for a hub carrier. Pittsburgh charges US Airways $8 to $10 per passenger. "The people US Airways used to run through Pittsburgh (are) now run through Philadelphia and Charlotte," Orr says. "When it costs $8 through one and 76 cents through another, and you can do either of them, which are you going to do? "When you produce the highest-quality product at the lowest possible cost, people will beat a path to your door," Orr added. For all airlines, Pittsburgh's average cost per passenger is about $10, said airport spokeswoman JoAnn Jenny. For each carrier, the cost reflects total charges (generally for facility leases and bond payments) divided by the number of passengers. Pittsburgh costs have risen "because US Airways pulled traffic out," Jenny said. Airport passengers totaled about 20 million in 2000: the 2009 number is about 8.5 million. Now charges, mostly fixed, are spread among fewer passengers.