There was a documentary about Apolcalypse Now and I think it was Coppola who said that they had to remove footage which showed US soldiers desecrating vietnamese corpses (even though these shots were based on actual photographs/eye witness accounts) because otherwise the US government refused to give them helicopters and whatnot.
Coppola didn't use American helicopters though, he borrowed them from the Philippine army. That's what Hearts of Darkness (the documentary you probably saw) revealed, at least.
If I recall; these helicopters kept getting re-routed due to a nearby conflict and this not only annoyed Coppola but was one of the reasons why the film was delayed and ran over cost.
