Mile-high Wi-Fi

Wang Lingli, 27, who flies frequently for business, was excited to hear that Air China has launched free in-flight Wi-Fi service, the first Chinese carrier to do so.

"It's terrific. If the service can be expanded, I no longer have to sleep or feel bored during the flight," said Wang.

The system, which had been tested since July 2013, debuted on April 16. According to an official statement from Air China, passengers can now log on to a limited number of websites on planes that have been equipped with GX Aviation, a global high-speed in-flight connectivity service that provides aircraft with data rates of up to 50 Mbps. Unlike earthbound Wi-Fi, this ground-to-air Wi-Fi system does not link to the external Internet. Moreover, the in-flight network can only be used with laptop and tablet computers, not smartphones.

The airline invited journalists and celebrities to experience the service. Among them was actor Wang Taili, one-half of the Chopsticks Brothers filmmaker duo. On his Sina Weibo microblog, Wang reported that he was able to send Weibo posts and video chat with his collaborator Xiao Yang, who was accessing the onboard Wi-Fi system on another plane. At 3,000 meters above the ground, the video chat ran very smoothly, with an average bandwidth of 10 Mbps.

Some experts still have concerns about the safety of the onboard Wi-Fi system, saying that it could interfere with the plane's communications. Air China's statement addressed this point by stating that the Wi-Fi system is physically separate from other systems on the plane, and thus will not affect air safety.

"The new technology has been used by many international airlines, including American Airlines, Emirates and Japan Airlines," said Xu Ke, a former pilot who now teaches at Zhejiang Police College.

Many airlines have now loosened the longstanding ban on smartphones, allowing them to be used - along with laptops and tablets - as long as they are set to "flight mode," which disables all wireless radio transmissions.

On March 20, Finland Airlines released a new service which allows the use of handheld electronic devices - including cell phones - during the entire flight, though passengers must set all devices on flight mode. The airline also provides in-flight Wi-Fi service.

"Air safety is the most important thing," said a passenger surnamed Chen who was taking an international flight from Xi'an in Shaanxi Province to Helsinki on April 1. "Even though the phone is set to flight mode, I am still afraid that there are some safety loopholes. Whenever I see anybody around me whose phone is not off, I will remind them to turn it off."

"I worry that the convenience of having access to the in-flight network will cause passengers to use their cell phones on board," said Wang.

In China, there is a very strict ban on the use of electronic devices on airplane flights. Passengers are required to turn them off during take-off and landing - and can only use them once the plane achieves a cruising altitude higher than 3,000 meters. Smartphones, however, must be turned off during the entire flight.

"This policy is to stop phones from interfering with the plane's navigation as the devices search for cell towers," said Xu.

Though experts disagree on whether cell phone transmissions can interfere with a plane's operations, Chinese authorities tend to take tighter measures to guarantee air safety. However, the authorities are mulling a new policy that would follow the general trend of the air industry in easing the ban on in-flight phone use, said Air China in the official statement.