We are awed by special effects in movies; the more destructive, the more exciting. For example, anyone who saw Apocalypse Now in a theater was impressed with at the disturbing opening scene in which an entire Vietnamese forest was set ablaze with napalm.
But that's just the beginning. Read stories of four other disturbing movie shoots at Cracked. Link
Most people are probably too distracted by one of the finest opening shots in film to actually contemplate how it was achieved.
After all, it's an impressive special effect for 1979. How did they go about making it look like a huge section of forest had been burned to the ground?
Surprise! They did it by actually burning a huge section of forest to the ground.
That's pretty much it. Around 1,200 gallons of gasoline were poured over the splendid palm trees and then set alight. Tires were also burned to generate more smoke for the shot, while canisters were dropped onto the area to look like falling napalm. Acres of the forest were destroyed in a matter of seconds. Fitting, for a shot that was supposed to visually demonstrate the mindless, indiscriminate destruction of war.
But that's just the beginning. Read stories of four other disturbing movie shoots at Cracked. Link
For the other big explosion in the movie, they had to have military jets fly over the jungle to make it look like they were the ones bombing the treeline. They had a pipe filled with gasoline for the explosion to simulate the napalm. Since they only had one pass with the jets, everything had to go off in one take. To get the jets to fly over the correct spot, they cut out big arrow shapes in the trees in the jungle so the pilots could navigate properly miles away.