Climatic conditions of hump route

The route starts from Sichuan, passes through Chongqing, Yibin, Luzhou and Kunming, Yunnan, and flies directly to Tingjiang Airport in the southwest of Tingsukya, the northeast border of India. The route spans many high mountains and deep valleys, and the peaks rise and fall, like the ridge of a camel. Along the way, there are the famous Himalayas, Gaoligong Mountain and Hengduan Mountain. Generally speaking, the height of the mountain is between 4500 and 5500 meters. Bypassing the snow line, the top of Yulong Mountain marked on the map is 5596 meters high. Yarlung Zangbo River, Enmeikai River, Nujiang River, Lancang River, Jinsha River and other rivers.

The route is often in bad weather, it often rains in rainy season, and the visibility in the air is almost zero. Cherapenzi, near Tingjiang River, has the heaviest rainfall in the world (the annual rainfall reaches 2646 1mm). After the rainy season, it is a thunderstorm season for several months, with changeable ascending and descending airflow and strong seasonal wind. Then there is severe icing, often the whole plane is wrapped in ice, and the strong headwind sometimes reaches more than 150 km per hour. Even the most experienced pilots can't completely guarantee flight safety.

The most impressive route over the hump is at the end of 1943. We took China Airlines flight DC-3 from Chongqing to Kunming, to Tingjiang and then to Kolkata. After taking off from Kunming, I joined the climbing route. Half an hour later, the sky began to deteriorate, and it continued to climb to 4200 meters. It was still thick clouds and the outside of the plane began to freeze. The pilot sprayed alcohol on the cockpit windshield with little effect. As the temperature continued to drop, the propeller began to freeze. Below the plane is a mountain canyon, and the height cannot be reduced, so we have to continue climbing. The thermometer indicates that the temperature continues to drop, and the cockpit windshield is completely covered with ice, entering a real blind flight. Although the pilots have flown on this route for thousands of hours and nearly a hundred times, they have never been completely covered with ice and can't see anything outside, just like flying in an ice kiln. The situation is quite grim.

The heating system is broken, and the temperature outside is MINUS 30 degrees Celsius. Fortunately, the engine is running normally, and the automatic indication of the ship's radio compass has also failed. The operator has been constantly adjusting the loop antenna outside the rotating machine to prevent freezing. The plane climbed to about 6500 meters like a snail, just at the top of the floor, and the tension was slightly relieved. However, the temperature in the cabin has dropped to a very low level, and the guests feel lack of oxygen and dare not walk around casually. There are also thick ice flowers on the inside of the window. The position of the plane measured by the pilot with the loop antenna shows that the plane is still on the route. However, it must be estimated that the radio is unreliable under the conditions of thunderstorm, snow and freezing, and it is obviously not allowed, but it seems to mean something. Where the actual position of the plane is, it can only be inferred and estimated by experience.

Flying on the clouds, the icing outside is estimated to be better, and the ice on the propeller still rarely falls off. Suddenly the engine banged a few shots, indicating that the gasifier was frozen. Sometimes a little fuzzy sunlight can penetrate the clouds. Although fuzzy, it can also be warm. Actually, it's still very cold. Intermittent sunshine always brings a little hope. Start the anti-icing hydraulic pump again to pressurize until the alcohol is ejected, and wipe the porthole glass by hand. Because it evaporates quickly, the ice will pass through your fingers, but when your fingers leave, you can see that there is not much ice on the hood and wing through the melted part, which will not cause great danger and people's mood will be more stable. In addition, it is estimated that the trend of the situation in the later period is getting better. The cumulative flight has exceeded four hours. According to conservative estimates, it has flown 650 kilometers, and it should have passed the hump, and it can be lowered a little. At this time, the thermometer shows that it is already zero degrees Celsius, indicating that the temperature has started to rise, which proves that it has indeed left the freezing area and hump mountain area.