What is Turbulence?
Understandably, a lot of people have a fear of turbulence when flying. I’m going to try and explain what turbulence is and why it’s nothing to worry about so that you can get on your next flight feeling confident and relaxed.
What is turbulence?
The best way to explain turbulence is like waves on the sea. If you’ve ever been on a boat, you’ve probably experienced a few waves. What happens to the boat? Nothing! You simply ride out the waves, perhaps slow down slightly so the effects are reduced, or take a different route. It’s a little uncomfortable and inconvenient but does not endanger the boat.
Just like the boat, if we come across turbulence all we do is ride the (air) waves.
A bit more science…
Turbulence is simply disturbed air, again similar to waves in the ocean. There are several different types.
Clear Air Turbulence
The one you are most likely to encounter in flight. This can be caused by jet streams. A jet stream is like a river of fast flowing air in the atmosphere. When this fast steam of air meets another mass of air with a different speed, direction or temperature, it can sometimes cause clear air turbulence. Like the wave breaking on the beach meeting the wave retreating back from the beach.
Convective turbulence is caused by vertical currents of air in an unstable atmosphere. Sometimes associated with thunderstorms and cold and warm fronts, this provides visible clues to the existence of turbulence that we can actively avoid.
Low Level Thermal
On warm summer days when the sun heats the earth's surface, different surfaces heat up at different rates. Certain surfaces, such as roads and sandy areas, are heated more rapidly than grass covered fields and much more rapidly than water. Isolated convective currents are therefore set in motion with warm air rising and cooler air descending. These are responsible for bumpy “rising and falling” conditions as an airplane flies in and out of them.
This has nothing to do with the weather, it is caused by other aircraft. There is low pressure at the top of the wing and high pressure at the bottom (needed for wings produce lift), air moves from the bottom to the top of the wing at the wing tip causing wing tip vortices or “wake turbulence”. It lasts for a few seconds before it dissipates, this is why air traffic control apply minimum spacing between aircraft for the required wake turbulence separation.
What do pilots do to avoid turbulence?
As pilots we do all we can to avoid turbulence. It starts in the crew room in the morning when we look over the flight plan. We look at the weather at departure, destination and en-route to see if there are any jet streams or convective weather that we need to be aware of.
In flight, in the aircraft we have a weather radar system, the radar sweeps the area ahead of the aircraft and detects water droplets (rain) and displays on the pilot’s instruments. Generally speaking the bigger the rain drops, the bigger the cloud, and the more turbulent it will be inside that cloud. As pilots we make a judgement on if we can fly through the cloud or fly around avoiding it. This is very useful at night, during the day we also rely on looking out of the window of course and anything that is very convective we avoid. Green is ok, yellow and red we avoid. The magenta is turbulence, this is displayed if the aircraft has the RDR-4000 system installed.
As far as clear air turbulence goes, it is very hard to predict and avoid as we can’t see it! This is why you are recommended to keep your seat belt on at all times when seated. In this case, if we encounter CAT we firstly slow down to our turbulence speed, ensuring the safety of the aircraft. We can then talk to ATC and ask if there have been any reports of turbulence in the levels above or below us, if not we will try and climb or descend out of it. Other wise we just have to ride it out, its uncomfortable and a bit inconvenient but not a danger to the aircraft.
Will the Aeroplane Break?
No. When the aircraft is designed, it is tested to withstand way beyond the forces that could be exerted by turbulence. Each aircraft has a design limit load, a maximum load that should not be exceeded operationally but the aircraft can withstand much more. Below you can watch a video of a Boeing 777 wing being tested. It fails at 154% of it’s design limit load. Proof your aircraft can withstand any turbulence.
Top Tips for Nervous Flyers
Pilots find turbulence as uncomfortable and inconvenient as the passengers so be assured we are doing all we can to minimise the effects and ensure your safety.
Distract yourself - if you are a nervous flier then perhaps consider investing in some noise cancelling headphones and make sure you have a good book or Netflix series you can get lost in.
Book a seat over the wings - you are closest to the aeroplanes centre of gravity and if we do encounter turbulence you’ll have the smoothest ride.
Avoid drinking alcohol and caffeine - this can intensify your anxiety and emotions making the situation worse.
Try to focus on your breathing, inhale for 4 counts exhale for 8
Aircraft are tested to the most extreme limits, they are built and designed to fly with no bother through turbulence .
Remember you are not in any danger.