Kenneth Branagh and Helena Bonham Carter will take off in the BBC Films/Distant Horizon production of “The Theory of Flight.”Pic is slated to start shooting later this month in various U.K. locales, including London and Wales. Scripted by Richard Hawkins, the pic is about a young woman with Motor Neurone Disease (Bonham Carter) who is taken care of by a young man (Branagh) who is hiding from life. The pic will reunite Bonham Carter and Branagh, who last worked together on “Frankenstein” for TriStar Pictures three years ago. Paul Greengrass is helming. Greengrass directed “The Fix,” a controversial soccer drama for the BBC. Anant Singh, David Thompson, Ruth Caleb and Helena Spring are producing. Distant Horizon and BBC have also produced such pics as “Sarafina,” “Captives” and “Face.” BBC picked the project out of its slush pile of unsolicited screenplays, marking the first of its kind to be made by the British firm in more than 20 years of submissions. Bonham Carter was last seen in “Margaret’s Museum.” Other recent credits include “Chinese Portraits,” “The Wings of the Dove,” “The Revenger’s Comedies” and Woody Allen’s “Mighty Aphrodite.” Branagh recently wrapped “Shakespeare’s Sister” opposite William Hurt. In the fall, he’s slated to star in Woody Allen’s newest project.