A trial-flight of a civil airplane with in-flight internet has taken off from Beijing. This Air China flight is open for public use. And for the first time, the public have been able to read emails during their flight.

A passenger jet with in-flight internet has taken to the skies over China for the first time. The plane is equipped with a wifi network that can connect with a communication satellite, allowing passengers to connect to the internet during the flight. It's as simple as logging on to the net when you're at home or in the office.

"You can send emails to your friends, and get a reply instantly. You can check the latest news or stock prices through an app provided by the airline company," said Zhang Yun, Director of Air China Inflight Office.

Despite the convenience, security is a concern. Electronic devices are strictly banned during flights. The cabin communication network provider has been conducting research into connecting a base station signal on the ground with a satellite signal without threatening flight safety.

"Our technology has been tested and approved by the civil airline administration authority. We passed the electromagnetic interference test, and in order to ensure full safety, our inflight internet service will open only after the flight has reached 3000 meters," Zhang said.

Unlike mobile phones, the current inflight internet technology has a relatively simple electromagnetic signal. Previous tests have managed to eliminate interference to flight operating systems. But the internet service won't be used during takeoff and landing.

Other airline companies such as Germany's Lufthansa, Emirates Airlines, UK's Virgin Atlantic Airways, and Southwest Airlines of the US also have this technology.