Summit Entertainment has picked up international rights to the Kenneth Branagh starrer “Theory of Flight,” produced by Anant Singh’s Distant Horizons Prods. and BBC Films.Also starring Helena Bonham Carter, the dark, contemporary comedy-drama about a woman with motor-neuron disease and her eccentric care-giver is directed by Paul Greengrass from a script by Richard Hawkins. The film wraps July 28 after shooting in London and Wales. Summit previously handled Antonia Bird’s “Face” for Distant Horizons. “Theory” will be introduced for sales at the upcoming Mifed in Milan in October. Distant Horizons will handle North American distrib rights.