If you’ve ever glimpsed the world through flight tracking app Flightradar24, you’ve probably noticed a few things: airplane “highways” over the Atlantic Ocean, high-altitude balloons from Project Loon, and a big gap in air traffic over Tibet. Maybe not the last one. But if you move to Tibet, you will see that the gap is there – and there is an absolute logical explanation here’s why.
The Tibetan Plateau covers an area of about 965,000 square miles, or just under four times the size of Texas, according to NASA and the US Geological Survey. Looking at Flightradar24, you can usually see aircraft flying smooth paths north and south of this vast area, but not directly across it.
Because planes avoid this area
That’s because it’s about one of the highest areas on Earthwith an average elevation of about 14,800 feet. In fact, it includes many important mountain ranges, such as the Himalayas, home to the world’s tallest mountain, Mount Everest. This extremely high area of the Earth has earned itself the nickname “the roof of the world”.
You’re probably thinking that airplanes fly well above 14,800 feet. And it’s true – the altitude is usually between 30,000 and 42,000 feet.
So why does the altitude of the Tibetan Plateau affect flights?
It all depends on the oxygen levels. If the aircraft decompresses at altitude, the oxygen masks will drop and the pilot will quickly descend to an altitude with more oxygen – ideally below 10,000 feet. (For reference, airplane cabins are usually pressurized to about 8,000 feet for comfort). Given the average altitude of the Tibetan Plateau, going that low is usually not an option, which can cause problems for any fighter aircraft. So, for security considerationsmany airlines choose to avoid flying in this area.
Another reason is that mountains create turbulence. You’ve probably experienced a few vibrations in the air while flying over the Rockies on a transatlantic flight—now imagine that happening all the time while flying over the entire Tibetan Plateau. It just won’t be convenient for all passengers.
There are five major airports in Tibet, so not all airlines avoid the area entirely. But unless Tibet is your final destination, your flight will likely skirt the Tibetan Plateau. But at least you’ll get a great view of the mountains while flying!
