Aviation: Fasten your seatbelts, please! | nd-aktuell.de

At the beginning of March 2023, a Lufthansa Airbus A330 will be flying over the USA. Suddenly the machine is shaken and sags so badly that the occupants are injured. The Airbus makes an unscheduled landing in Washington and seven people have to be taken to hospitals. The incident brings into focus a risk of air traffic that is rarely paid attention to by the public: turbulence. With a new app, pilots now have the opportunity to react better.

Turbulence is one of the biggest risks in air traffic. Commercial aircraft all over the world are confronted with this phenomenon every day. This often results in injuries and sometimes even deaths – usually because the passengers ignore the pilots’ seatbelt instructions.

A few examples among many: Almost at the same time as the Lufthansa flight, an A330neo from the airline Condor encountered turbulence while flying from Frankfurt to Mauritius. 20 inmates are injured. While flying from Tokyo to Honolulu, a United Airlines Boeing 747 is rocked by violent turbulence over the Pacific. The captain asks the passengers to fasten their seatbelts. Many passengers do not heed the instructions. A little later, the turbulence increases and becomes so severe that the captain even fears structural damage to the aircraft at times. Meanwhile, horrific scenes take place in the cabin. Passengers, hand luggage and food are thrown through the air. One passenger dies, 18 people are seriously injured and 171 are slightly injured.

The weather radar cannot detect air movements.

Corresponding incidents in air traffic are meticulously recorded by the relevant aviation safety authorities and classified as accidents or incidents, depending on the extent of the impact. Anyone who takes the trouble to evaluate the relevant reports will come across an almost unmanageable number. There are no globally summarized figures. There is no information available about the global number of deaths and injuries.

The US Aircraft Accident Investigation Board (NTSB) is the world leader in recording. She investigates accidents and incidents that occur in U.S. commercial civil aviation. In one study, she lists 432 incidents related to turbulence that occurred over the 16-year study period. In 225 cases, aircraft occupants suffered serious injuries, and in 1,109 they sustained minor injuries. On average, the authority concludes, there are 26.9 turbulence-related incidents per year, with 14 serious and 69 minor injuries.

Turbulence is the movement of air that the aircraft is exposed to during its journey. Their occurrence can have a variety of reasons. They occur as a result of storms, over desert areas as a result of rising warm air and through uneven ground hit by the wind. For this reason, flight close to the ground is often particularly turbulent. This also applies to flights over mountains, where the uneven ground causes strong up and down winds. Turbulence occurs much less frequently during cruise flight at high altitude, but can also occur, for example, at the edge of large jet streams. These are powerful and very powerful air currents that flow around our globe at high altitudes.

However, there are no “air holes,” as passengers often call turbulence, in the atmosphere. If the aircraft suddenly sags during flight, this is due to the special shape of the wings. These are shaped in such a way that their special curvature on the top creates lift when the aircraft is accelerated by its engine. If a strong gust of wind hits the wing from the front during the flight, this temporarily increases the lift. If the gust of wind suddenly dies down, the aircraft will sag for a brief moment.

A weather radar is part of the basic equipment of modern airliners. It is located in the bow of the machine. However, it cannot detect air movements, only cloud formations. Reason: The water drops contained in it reflect the radar beams. Based on the cloud formations shown – for example storm clouds – the pilots can usually estimate in advance whether turbulence is to be expected during the flight. Turbulence that does not occur in connection with clouds cannot be detected early.

Nevertheless, pilots often hear about such turbulences via radio, as the crews of aircraft flying ahead warn those following. Passengers are then warned by the seat belt signs being switched on and corresponding announcements being made. However, the pilots cannot force the warnings to be implemented. It is the sole responsibility of the passengers.

The new app, designed to minimize the risk of turbulence, was developed by Sita, a communications provider specializing in aviation. It’s called Sita Ewas and it summarizes information from numerous weather sources. This includes, among other things, the turbulence forecast from the German Weather Service. Ewas combines this data with real-time turbulence measurements from other aircraft around the world, as drivers know from traffic jam reports in the traffic app while driving. This allows pilots to, for example, adjust their routes during the flight and thus fly around turbulence zones. The app is already being used by Air France and the Lufthansa subsidiary Swiss.

Turbulences are not normally dangerous to the aircraft itself. It is designed for much greater loads. The acceleration forces that occur during a flight are measured using the unit g. Typically, during a quiet cruise on a nice summer day, loads of 1.3 g can occur. In an autumn storm with strong gusts it is around 1.8 g. In tests on static breaking loads, the Airbus A340 has already endured 4.5 g.