Turbulent weather

Is to reduce the lift. It causes the plane to vibrate negatively, so the pilot can't control the plane.

Atmospheric turbulence: irregular air movement with changing wind speed and direction. Its importance lies in its ability to stir and mix the atmosphere and distribute water vapor, smoke, other substances and energy at all heights. Atmospheric turbulence near the ground is different from atmospheric turbulence at high altitude. In the range of hundreds of feet near the ground, due to solar radiation, the turbulence has obvious daily variation and reaches the maximum around noon. When solar radiation heats the earth's surface, the earth's surface warms the air, and warm and light air rises instead of cold and heavy air. This air movement and the disturbance around the ground obstacles make the low-altitude wind extremely irregular. At night, the ground cools rapidly, and the air near the ground becomes cold; When the air on the ground becomes colder than the air above it, a stable inversion is formed. In this case, the wind speed and gust decrease sharply. On cloudy days, the low-level air temperature changes little from day to night, and the turbulence is almost unchanged. Above 1000 meters, the friction effect of topography on wind is greatly reduced, and the small-scale turbulence unique to the lower atmosphere does not exist. Although high-altitude winds are usually regular, sometimes there is turbulence enough to affect flight. Under certain conditions, if the ground is heated strongly and the humidity is high, large pieces of air will rise and form huge cumulus clouds, so thunderstorms will often occur.

Clear-sky turbulence: under clear-sky conditions, the irregular airflow at an altitude of 7- 12km. It is harmful to aircraft flight. Turbulence is caused by a large wind gradient near the jet stream, where fast-moving air is close to much slower-moving air. Clear skies are the most turbulent in mountainous areas.

Turbulent wake: the irregular air movement caused by the passing of an aircraft, that is, the wing tip vortex pulled out at the wing tip. The intensity of tip vortex will gradually weaken with time. It is very dangerous for an aircraft to be in the wake of another large aircraft when taking off or landing, so it is required to have a certain time interval when releasing the aircraft, and release the small aircraft first and then release the large aircraft.

Turbulence not only affects the comfort of flight, but also sometimes poses a major threat to safety. Turbulence (or thunderstorm) caused by cumulonimbus or cumulonimbus, clear-sky turbulence and turbulent wake with strong intensity are very unstable in speed and direction. Especially, when an aircraft encounters turbulence with a high ascending or descending speed, it will bump up and down like a ship sailing on a turbulent sea, and may even get out of control, resulting in flight accidents and casualties. If there is a thunderstorm in front of the plane during the flight, it must fly around, otherwise it will be very dangerous; Because the clear sky turbulence is difficult to predict, it is difficult to observe with radar, which is more harmful to flight. 1in March, 1964, a radar device named "cat-spy" was used, which can show the possible bumps in front of the plane at 16 km. As for the turbulent wake, it can be avoided as long as the flight interval is paid attention to.

Accidents and incidents caused by turbulence

Every year, incidents of flight accidents or accident signs caused by turbulence occur from time to time. A few cases are for your reference: 1 On July 8th, 1992, a Fokker F27 aircraft of British Airways had an accident when it approached and landed at Heathrow Airport in London, England, and1crew members were injured. Accident: Fokker encountered a strong wake when approaching and landing three minutes behind a Boeing 747.

1993 On June 17, an An -26 plane of Tajikistan National Airlines crashed in Tbilisi, Georgia. All five crew members and 35 passengers on board were killed. Cause of the accident: It is reported that the plane lost control in strong turbulence.

1993101on October 27th, a Boeing 747 of Northwest Airlines crashed while cruising over the Pacific Ocean, with 13 crew and 108 passengers on board. Accident course: The plane encountered clear sky turbulence during cruising flight, causing 27 passengers on board to be injured, 9 of whom were seriously injured.

On September 8, 1993, an Austrian Airlines MD-82 plane encountered clear sky turbulence when approaching Linz airport, resulting in an accident. There were 9 crew members on board, 10 1 passengers, of whom 19 passengers were injured and 3 passengers were seriously injured.

Suggestions on avoiding bumping injuries.

Turbulence is the airflow generated by the atmosphere itself and the flight of large aircraft. Although people can't control the occurrence of turbulence, it is entirely possible for modern technology to avoid strong turbulence or avoid the damage caused by turbulence. The following suggestions are used to prevent cabin injuries caused by turbulence:

(1) Flight personnel should make full use of meteorological data to analyze and predict the bumpy airspace, forecast the general weather situation, and avoid bumpy routes and altitudes;

(2) The cabin personnel should master the meteorological conditions, know which airspace and which stage the plane will encounter bumps, and make preparations in advance; When encountering strong bumps, instruct passengers to fasten their seat belts while sitting in their seats.

(3) Passengers should get into the habit of wearing seat belts all the time, especially when sleeping during long-distance travel. If you encounter sudden strong airflow, please fasten your seat belt quickly.