You’re sitting comfortably in an airplane seat. Maybe you’re watching a movie or playing a game. The snack and beverage cart is just a few rows in front of you. It’s almost your turn!
Suddenly, the seatbelt sign comes on. The flight attendant pushes the cart to the back of the plane. The plane starts to bob up and down. A voice comes over the loudspeaker:“Ladies and gentlemen, we are experiencing turbulence”
Turbulence can be scary. But like many things, it’s a little less scary when you learn the science behind it.
What is the turbulence?
Turbulence refers to unsteady movements in air or water. When you’re in a plane, turbulence results from changes in airflow. Airflow can refer to the movement of air from one area to another. It can also refer to the movement of air relative to the surface of a body travelling through it – like an airplane, for example.
There are four main causes of turbulence:
- Thermal turbulence.
- Mechanical turbulence.
- Wind shears.
- Wake turbulence.
What is thermal turbulence?
Turbulence caused by rising warm air is called thermal turbulence. Warm air rises because of convection. That is a type of heat transfer that occurs in fluids (liquids and gases).
What is mechanical turbulence?
Mechanical turbulence happens when natural or human-made objects on the Earth’s surface disrupt airflow. For example, mountains and tall buildings can cause mechanical turbulence.
What is clear-air turbulence?
Have you ever experienced turbulence in a plane flying through what looked like a perfectly clear blue sky? It’s caused by clear-air turbulence. As the name suggests, it happens in clear, cloudless conditions.
What is wake turbulence?
Finally, airplanes themselves can cause turbulence. When they push through air, they create eddies. And these eddies cause wake turbulence. It’s why pilots can’t take off or land immediately after another plane. It’s also why you never see a plane flying directly behind another one.
Predictable turbulence along the route
Nonetheless, the risk of turbulence can generally be predicted. Mountain wave turbulence is easy to predict along a route, since it comes from wind interacting with mountain ranges. There can be lenticular clouds above mountain tops that serve as a natural early warning for turbulence.
Convective turbulence comes when ground surfaces change. Convective turbulence is more of a lower altitude problem than a higher one. Flying over obstructions such as buildings or mountains can also create strong convective turbulence that can easily disturb an aircraft’s flight path. Yes, mountains can produce more than mountain wave turbulence.
Using weather radar
Weather radar can help predict convective turbulence and clear air turbulence. Most commercial aircraft now pack weather radar – from the Airbus A321 to the Boeing 777.
Weather radar can pick up weather systems sufficiently ahead to warn of precipitation and turbulence, allowing the fast-moving aircraft to divert in time to equally protect the humans and the aircraft.
Nonetheless, as an aircraft’s weather radar has only so much range, requiring sharper turns to respond, there is another way to detect turbulent weather ahead when inadequate forecasting. This means allows aircraft to make softer turns while responding to real-time conditions.
MANAGING SEVERE TURBULENCE FROM THE CABIN
1- A prioritized preparation
Once advised by the flight crew of an anticipated turbulence, the cabin crew should prioritize their duties based on the time available before the turbulence encounter in order to best prepare the cabin, as per CCOM recommended procedure:
- First, they must stow and secure large items such as trolleys and remove bottles from the cabin and galley surfaces. Any hot liquid must be safely disposed of.
- The cabin crew must then secure the cabin and ensure all lavatories are unoccupied.
- Once the cabin is secured, the cabin crew must secure the galleys.
- Cabin crew must then return to their station, fasten their seatbelt, and inform the purser that the passengers and themselves are secured.
- Then, the purser must inform the flight crew that the cabin is secured.
Ensure personal safety first
Most injuries in the cabin happened to passengers or crew members not seated with their seatbelt fastened during severe turbulence. Cabin crews are more exposed to risk of injury due to sudden turbulence because they are often standing during service.
The cabin crew must ensure their own personal safety first if sudden severe turbulence is encountered. The cabin crew must take the nearest available seat and securely fasten the seat belt. The nearest seat may be a passenger seat.
Tidy cabin and galleys for safe flights
Any loose object in the cabin can become a projectile during turbulence. Keeping the cabin and galley tidy throughout the flight reduces the risk of injuries and damage to the cabin should an unexpected turbulence event occur.
Passenger awareness on the use of seatbelt
The most effective way to prevent injuries during turbulence is to keep seatbelts fastened. It is therefore key that passengers are aware of this and are encouraged to keep their seatbelt fastened at all times.
Passengers must be made aware that they are obliged to comply with the FASTEN SEATBELT sign at all times when set to ON.