China's civil aviation authority, seeking to head off an upsurge in consumer complaints about domestic air travel, issued a plea this week to long-suffering travelers to stop complaining so much.

"We hope to increase consumers' understanding about the special nature of the civil aviation industry, so that together we can create a cosier, more harmonious aviation travel environment," the General Administration of Civil Aviation of China said on its Website (www.caac.gov.cn).

"What must be stressed is that safety is at the root of airline travel, and on-board service revolves around this," it said.

"That is what restricts the type of food carried, as well as the fact that on-board food is frozen first for freshness then reheated, so naturally the flavor suffers."

In the past, Chinese airline passengers may have put up surly cabin crew, decrepit in-flight entertainment systems and unexplained delays where aircraft full of people are just left on the tarmac.

But lately they've fought back by refusing to leave planes until compensation is paid for late flights, storming runways in protest and breaking down locked doors when herded into lounges after unannounced diversions to remote airports.

The airlines counter that it is the passengers who are unruly and poorly educated about flying, adding that they are spending billions of dollars on new aircraft and improving service, especially ahead of the 2008 Beijing Olympics.

"Flight punctuality is vulnerable to weather, emergencies and other unpredictable factors," the statement said.

"The compensation for delays varies according to the marketing strategies of airlines."

A China Eastern Airlines official, who requested anonymity, said yesterday, "We will try our best to comfort delayed passengers and allocate aircraft to reduce late flights."

"But delays occur for complicated reasons and are often uncontrollable by the airlines."

Mark Zhu, a 26-year-old frequent traveler, said delays are common on the Shanghai-Beijing route.

"I was compensated 200 yuan (US$25.60) once when my flight was late by six hours," he said. "But the compensation didn't satisfy me as the carrier kept offering different reasons why the flight was delayed."

On the luggage losses, the statement said passengers should not pack valuables and should use strong suitcases.