In any case, the film production, as documented in Hearts of Darkness, was a fiasco. To quote Very Short List:
Narrated by Coppola’s wife, Eleanor (who also shot the on-set footage), and directed by Fax Behr and George Hickenlooper, Hearts plays like a paint-by-numbers demonstration of how not to make a big film: The Apocalypse Now production is underfunded, the crew is overworked, and the script is unresolved. The actors are either too high (Dennis Hopper), too sick (Martin Sheen, who suffered a heart attack on the set), or too weird (Marlon Brando) to perform; meanwhile, monsoons destroy the sets.
It's a great documentary about the making of a classic film. Check it out.