American Airlines is expanding in-flight WiFi service to 150 aircraft this year, allowing passengers to surf the Web and check their e-mails while in the air.

The planned expansion of the broadband service comes after a six-month pilot program where American Airlines, using technology made by Itasca-based Aircell, tested the WiFi system on 15 Boeing 767-200 aircraft. Those planes flew cross-country routes between New York and San Francisco, Los Angeles and Miami.

American Airlines will restructure 150 of its MD-80 aircraft with Aircell’s Gogo system. Next year, 153 of the carrier’s 737-800 planes will also have the WiFi technology, bringing the total number of Gogo-equipped aircraft to more than 300 by the end of 2010.

“The MD-80s and the 737s basically fly to all American Airlines cities throughout the continental U.S.,” said Doug Backelin, the carrier’s manager of in-flight communications and technology. “It’ll be coming to an airport near you very soon.”

The service does not come for free though. It will cost $12.95 for flights of more than three hours and $9.95 for flights shorter than three hours. Aircell chief executive Jack Blumenstein said the service’s expansion will enable his company to offer a greater variety of pricing plans, with possibilities ranging from a day pass to a subscription for frequent flyers.