Some analysts expect the punctuality of domestic flights from the eight airports will see a substantial improvement after implementation of the new policy, but others doubt that much will change.

"It's like a road with room for 100 cars, and then 200 cars swarm onto it. You have to make arrangements," said an official with the air traffic management bureau who did not want to be identified.

He questioned what a pilot should do if a flight cannot land at a designated airport because of air traffic control.

"Waiting for a landing up in the air is not a good solution. It burns more fuel and increases passenger anxiety," he said.

Huang Jinxiang, an industry analyst with Haitong Securities, said the third quarter is the traditional peak season for flights, and there are frequent thunderstorms from June to August, affecting flights extensively.

Jiang Jintao, a medical worker in Tianjin, said: "It is understandable that rain or thunderstorms will ground flights, but what passengers want is merely that the airline give us a clear explanation and notice in advance instead of always referring to air traffic control and keeping silent about schedule changes.

"I know airlines are not able to change the situation solely by themselves, but I hope they can show more respect to passengers and improve service."