According to 2017 statistics, for civil aviation alone, there are more than 100,000 flights on Earth every day. Usually based on an average flight time of two hours per flight, there will be more than 10,000 civil aircraft flying in the sky at any time of the day.
Although there are a lot of airplanes flying in the sky, if you can observe these from space, you will see that there are basically no planes flying over some locations on Earth, no such as the Antarctic and the Himalayas. Antarctica is relatively easy to understand, it is not a place to be inhabited and there is nothing interesting about flying there by plane. But somewhat confusing is that there are no planes flying over the Himalayas.
Although there are relatively sparsely populated areas there, the surrounding area is extremely densely populated. Why didn’t civil aircraft fly over there?
The Himalayas are about 2,400 km long from east to west, from north to south from 200 to 300 km, with an average altitude of more than 6000 meters. The highest peak of Mount Everest is 8,848 meters and there are more than 100 peaks over 7,200 meters. This means that most civil aircraft can fly over here comfortably because the ideal altitude for passenger aircraft is 10,000 – 12,800 meters.
The record height achieved by a jet is 37,648 m, set by Alexandr Fedotov in 1997 in a MiG-25M.
But in reality, it is very rare for civil aircraft to fly over this mountain range and the main reason comes from safety issues.
First, in the event of a pressure drop incident, the aircraft needs to quickly descend to a safe altitude below 3,000 meters to wait for the opportunity to handle. In addition, the aircraft engine failures also need to be reduced to less than 3000 meters to ensure normal engine operation. Meanwhile, the average altitude of the Himalayas is 6000 meters so when the above incidents occur, aircraft flying over the Himalayas will inevitably crash.
Second, the Himalayas have a variety of terrain but almost no flat, in this area there are only two “kind” airports, the runway of Lhasa Airport is 4000 m long, and Kathmandu Airport is 3350 long. m. And in emergencies where it is necessary to land, civil aircraft will definitely not be able to land here. Civil jets fly at an ideal altitude of about 10,000 meters, and also need a 10,000-meter plains to slide down slowly before they hit the ground, and in the Himalayas the plane that wants to land is only possible. slide more than 1,000 meters, and then accidents are obvious.
Third, the turmoil in the Himalayas was also a problem. There is very little pollution near the Himalayas, so atmospheric disturbances are very obvious, but when flying over here the radar is difficult to detect so the pilot is difficult to detect, so the aircraft will be more likely to fly in. Crowded noise area, this will cause injury to the crew and passengers. Air turbulence is the number one cause of non-fatal plane crashes, according to the FAA report.
Fourth is the issue of fuel freezing. Jet fuel can freeze below minus 47 degrees, and flying at high altitudes in the Himalayas for long periods puts the fuel at greater risk of freezing. Planes often choose to lower altitude to avoid this problem. However, in the Himalayas, how do you lower the elevation?
The vast size, enormous range of heights and intricate topography of the Himalayas mean this mountainous region has a wide range of climates, from humid subtropical foothills to dry, cold desert conditions in the west. Organ of the mountains. For much of the Himalayas – in the south of the high mountains, except in the farthest west, the most characteristic characteristic of the climate is the monsoon. Heavy rains come in the southwest monsoon in June and last until September. The monsoon can seriously affect traffic and cause major landslides.
So the main reason the plane rarely flies over the Himalayas is because the safety risks are much greater than elsewhere.
The ideal altitude for passenger aircraft is 10,000 – 12,800 meters. If the plane flies too high, the oxygen concentration in the air will be too low, making it difficult to burn the engine, but too low the air resistance will be greater.
When a problem occurs with an aircraft at 10,000 meters, such as the engine shut down, the pilot will have more time to troubleshoot than if the plane is only 3,000 meters. The plane can still land safely when both engines fail. So having the time to prepare and do that can save lives.