As an expert builder using the grace that God gave me, I laid the foundation, and someone else is building on it. But each person must be careful how he builds on it. According to the grace of God given to me, like a skilled master-builder I laid a foundation, but someone else builds on it.
The most-advanced helicopters can fly up to 300 miles before having to refuel. How long any particular helicopter can fly without refueling depends on the size, weight and age of the helicopter.
In general the aircraft must be at least 500 feet away from any person, vessel, vehicle, or structure. In congested areas the aircraft must stay 1000 feet above the highest obstacle within a 2000 foot radius of the aircraft. There are special rules for helicopters that allow them to fly closer than these general limits.