Legends of Flight was released in 2010. The film is still exhibited by select IMAX theaters and other giant screen theaters, including the Smithsonian National Air and Space Museum in Washington D.C. Check your local theater for availability, dates and times.
The film is also available on Blu-ray and Blu-ray 3D from leading local and online retailers. Here are some examples:
(Links and availability from specific retailers subject to change).