Starting today, air travelers of 5 airlines in the US territory will be able to use the in-flight WiFi to access to Facebook for free. The participating airlines are  Virgin America, United Airlines, American Airlines, Delta, AirTran, US Airways and Alaska Airline.

The main in-flight WiFi service provider GoGo also offers normal access for extra costs ranging from $4.95 to $12.95 depending on the distance. In a recent flight from Orange County to Charlotte, NC on US Airways I paid $7.95.  Multi-device (smartphone, laptop, iPad) access is available but not concurrent.

In a recent study, email and Facebook are the most used in-flight. Gogo serves 1,100 commercial aircraft (or about 3,800 flights a day) and 5,000 private planes.

It is not clear about the duration as well as the goal behind this offer. As we know only between 7% to 10% of passengers on WiFi enabled aircraft are using WiFi. The offer could lure more travelers to discover the service.

Update: The offer is for the month of February only.

[Via USAToday]