Why don’t planes fly at 60,000 feet?
The sweet spot is between 35,000ft and 42,000ft. Here the air is thinner, meaning the plane can fly faster and burn less fuel. Any higher and there will not be enough oxygen to fuel the engines, and lower creates a greater air resistance. Flying between 30,000 and 40,000 feet allows commercial aircraft to operate more efficiently and save more fuel, which also helps save money. At those altitudes, the air is thinner, so the aircraft experiences less drag.