In fact, the thriller was actually based on the true story of Joel Kaplan, and his incredible real life escape via helicopter from Santa Maria Acatitla prison in Mexico City, after being framed for murder by the mob.
The local Romany community from Figueras were used as extras, because of their dark Mexican looks.
The tale is told with plenty of poetic licence but according to the real life story, New York businessman Caplan was imprisoned by the Mexicans in 1962 on a highly questionable murder charge, with rumours of CIA involvement.
Nine years later, his sister hired a California helicopter pilot and a helicopter painted in colours similar to that of the Mexican attorney general, to land in the prison courtyard and spirit him away.
Jay Wagner (Robert Duvall) is framed by the mob and sent to prison in Mexico. His wife, Ann (Bronson’s real life wife Jill Ireland) turns to swashbuckling charter pilot Nick Colton (Bronson) for help. Colton accepts, but the men who framed Jay will do whatever they have to make sure he doesn’t escape