China's three biggest airlines all reported surging net profits in the third quarter, statements showed, as the country's economy stablises. Net profit for China Southern, Asia's biggest airline by fleet size, leaped to 3.31 billion yuan ($425.1 million) in the three months to September, nearly three times the 1.18 billion yuan made in the same period last year, it said in statement to the Hong Kong exchange on Friday. Shanghai-based China Eastern Airlines said in an exchange statement its net profit almost doubled year-on-year to 3.46 billion yuan.