Air Asia aircraft may have faced the mountain of cumulonimbus

Adverse weather factors such as thunderstorms or aircraft freezing may affect AirAsia's itinerary. When the plane disappeared, in the area there was a cloud of rain (cumulonimbus) towering, rising at a height of more than 15km.

Airline experts require caution when making an assessment of the cause of an aircraft failure, including factors such as weather, failure of law or pilot's fault. However, available weather data can hypothesize the impact of weather or climate conditions on flight activity, and become a central issue in any survey.

According to AirAisia, the AirAsia QZ8501 flight captain asked for permission to divert and raise the altitude of the last contact with the air traffic control station before disappearing, due to weather conditions. advantage. However, the air traffic control station could not approve the request to raise the height to 9.8km to 11.5km because there was another aircraft operating above.

Complex weather

Satellite imagery on December 28 shows, around the time when AirAsia aircraft were missing there were signs of a major storm in the vicinity.(Photo: NOAA)

Satellite images recorded at the time of the missing plane describe complex patterns of thunderstorms, with towering rain clouds, bulging at a height of more than 15km.

Heavy rain and severe flooding have been recorded in this area for several weeks. An official from the Indonesian Meteorological Agency told WSJ that vertical and dense cumulative clouds were observed on the flight path of QZ8501.

"In general, rain clouds are quite dangerous for aviation because it causes storms with lightning and heavy rain , " WSJ quoted an unnamed official as saying. This may explain why nearly 40 minutes after takeoff, the pilot asked permission to raise the altitude.

In addition, the aircraft area was last observed in the Convergence Zone between the two Tropics (Intertropical Convergence Zone), a region of variable weather. This is an area near the equator known for large storms, where trade winds in the northern hemisphere and the southern hemisphere intersect. ITCZ is said to be one of the reasons behind the mysterious disappearance of Air France in the Atlantic in 2009.

High altitude simulation of QZ8501 and rainy cumulus cloud.(Graphic: Weather Channel)

Heavy storms and rains, which formed along the ITCZ ​​region, affected earlier Southeast Asia, flooded and forced tens of thousands of people in Indonesia, Malaysia, Thailand and Sri Lanka to evacuate.

Tim Vasquez, a meteorologist who worked for the US Air Force, analyzed the weather data available and admitted that, despite the presence of strong storms, the instability of the atmosphere is not strong enough to cause turbulence or the phenomenon of sudden wind (microburst) .

However, Vasquez believed that the aircraft could encounter a freeze on the aircraft, causing the aircraft's weight to be larger and disrupting the air flow through the wing parts. Meteorologists identify weather as a factor, or a combined factor. However, this is only an assessment based on meteorological information, not a final decision on the cause of the disappearance of the aircraft.

The role of the pilot

According to commercial pilot Ron Baker, on a flight, they want to avoid strong thunderstorms from at least 30km (horizontal). Like all modern aircraft, AirAsia's Airbus 320 is equipped with an on-board weather radar system, which helps pilots identify areas with heavy rainfall or storm center location, intensity and distance. The radar display often overlaps the navigation display, allowing them to observe the area of ​​the impact of the weather on the flight path. This information, along with advice from the pilot's air traffic and other control stations, is used to make decisions about safe flight processes around weather areas.

Severe thunderstorms (shown in red) with a height of more than 15km near AirAsia's flight route.(Photo: ABC News)

Typically, pilots will send a small difference in flight requirements, enough to navigate and avoid storms. Sometimes, airplanes can even fly higher. In case the holes in the path of the storm are too small, or the height of the storm is too large, the aircraft cannot pass, misalignment or other road travel will be required. Although the weather is difficult to predict, pilots still have remedial options to make when deciding how to fly safely, even if that means changing routes, or redirecting to the airport. other.