Maybe you fly a lot, but how much do you know about airplanes?


Maybe you know from movies that planes fly at 30,000 feet, but why do they have to fly at that altitude? Can't they fly higher or lower?


1. The higher the plane flies, the faster it goes.


The air pressure and density of the earth's atmosphere decreases with increasing altitude, and the resistance of airplane flight mainly comes from the density of the air, so the higher the density, the greater the resistance.


The higher the density, the greater the resistance. When the flight altitude is higher, the lower the air density, the lower the resistance, the lower the resistance, the faster the flight speed will be, in effect, shortening the flight time.


In addition, low drag also saves fuel, so long-distance flights usually fly at 40,000 feet.


Civilian passenger aircraft flight altitude is determined by the flight distance to the destination, the farther the distance, the higher the flight altitude will be.


2. Optimum Flight Altitude


The aviation industry considers the optimum altitude to be between 35,000 feet and 42,000 feet.


When an airplane flies too high, the air is too high and the oxygen is too thin to burn the engine; and when an airplane flies too low, the air resistance will be greater.


The optimal altitude for an airplane is also related to its weight, with heavier airplanes flying lower and lighter airplanes flying higher.


When there is a balance between fuel efficiency and energy, that is the optimal altitude for an airplane.


3. Avoid heavy air traffic


The higher a plane flies also means that it can avoid other air traffic, such as smaller planes or helicopters, as well as insects and birds.


Smaller planes fly at 10,000 feet to 20,000 feet, so a civilian airplane would fly at 35,000 feet to avoid heavy air traffic.


4. Allow pilots more time to deal with unexpected situations.


If an aircraft has an emergency at 35,000 feet, such as an engine failure, the pilot will have more time to deal with the problem than if the aircraft is flying at 10,000 feet.


However, you can rest assured that even if both engines fail, the airplane will still be able to land safely.


5. Is there a minimum altitude?


The Civil Aviation Safety Authority (CASA) in Australia, the Civil Aviation Authority (CAA) in the United Kingdom, and the Federal Aviation Authority (FAA) in the United States all have a common minimum altitude for flight.


This applies more to small aircraft than to civil aircraft, and any aircraft in a built-up area must fly higher than 1000 feet.


6. Why don't airplanes fly higher?


Since the oxygen content of the air decreases with altitude, and aircraft engines need sufficient oxygen to operate, the most suitable altitude for aircraft engines is 35,000 feet to 42,000 feet.