Complex sentence: Many scenes were shot on a mountaintop, and he and the crew had to drive 40 minutes before reaching film's base camp and if weather was okay then they could board the helicopter to reach their destination along with their supplies.
Split into simpler sentences: Many scenes were shot on a mountaintop, and he and the crew had to drive 40 minutes before reaching the film's base camp. If the weather was okay, they could board the helicopter to reach their destination along with their supplies.