China 'suffers worst flight delays' 12 July 2013 Last updated at 10:22 China's major airports have the worst flight delays in the world, a report from travel industry monitor FlightStats says. According to figures from around the world in June, Beijing and Shanghai airports came bottom for on-time flights, the US-based firm said. Eight of the 10 worst-performing Asian airlines in terms of delays were Chinese carriers, the report added. The report did not explain the reasons for poor performance. The report looked at "on-time performance of scheduled passenger flights" by top airlines, as well as "top performing airports based on their reported departure performance" in June, FlightStats said on its website. "A flight is considered on-time if it arrives or departs within 15 minutes after its scheduled take-off or landing time," the report says. Among 35 major international airports, the report ranked Beijing Capital International Airport lowest for on-time performance. It figure for on-time departures was 18.30%, with 42.02% of flights falling under the "excessive" category - a delay of 45 minutes or more. This means that only a fifth of the flights left on time and close to half of flights were delayed for 45 minutes or more. The Shanghai Pudong International Airport, second from bottom, fared slightly better, with on-time flight departures at 28.72%. Under the "excessive" category, it scored 34.22%. Tokyo's Haneda airport topped the list, with an on-time performance of 95.04%. Osaka International Airport, which did not feature in the main list but in a separate Asian ranking, did even better with 95.88%. Meanwhile, China United Airlines was ranked the worst-performing among the 41 Asian airlines listed on the report, with just over a quarter of its flight performing on time. The Asian airline with the best on-time rate was South Korea's Air Busan, with a near-perfect 96.77%. Some Chinese industry insiders blame "air traffic volume as the cause of flight delays," China Daily newspaper said. In China, about 80% of air space is restricted to military use, the paper said. But it also quoted an expert as saying that China's airports could not keep up with commercial airline growth.