I recommend reading the full description from last July’s blog post, especially this quoted portion:
“Microsoft Flight Simulator users can tour the Flying Eye Hospital in full hospital mode with stunningly authentic detail and learn more about Orbis’s mission to train and inspire local teams to save sight in their communities by accessing the plane free-of-charge through an in-game news link or directly via Microsoft Flight Simulator Marketplace. The plane, however, is not currently available for flight.”