High expectations among mainland passengers led to a sharp fall in airline satisfaction levels last year, according to the Customer Working Committee of China Association of Civil Aviation.

After a survey of 30,000 mainland travelers, it discovered the overall customer satisfaction index last year was 69.9, down nearly 10 points from 2007.

"It is probably because Chinese travelers are much more experienced nowadays," said Committee Director Liu Yimei on Jan. 22. "They hold high expectations toward air travel service but it just makes them more likely to feel disappointed."

Air China and China Southern Airlines were voted the best mainland companies, with China Eastern, Hainan Airlines, Shenzhen Airlines, Sichuan Airlines and four others chosen as "satisfying carriers".

Most of those polled spoke highly of the carriers' in-flight service, which scored 79.8 points, and booking service (74.4 points). But most were dissatisfied with communication during flight delays, which scored 70.2 points, as usual.

Chen Yukun, 64, an engineer from Beijing who travels on average four times a month, said airlines and airport operators always failed to inform passengers about two things during a delay: why it happened and when the plane will take-off.

"The situation has improved a lot but the new problem is that, after boarding, passengers are often kept in their seat waiting for air traffic control to let the plane go. It can take an hour," he said.

The poll also found that domestic travelers were dissatisfied with the seating space, food service and luggage claim.

The committee has urged airports to improve service after flight delays, as well as signs in terminal buildings.

Beijing Capital International Airport (BCIA) was voted the best airport.