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.
The maximum altitude which can be reached during forward flight typically depends more on the ability of the engine to breathe the thinner air than the rotor's ability to provide lift. Turbine-engined helicopters can reach around 25,000 feet.