Is Turbulence Dangerous in Commercial Aircraft

Turbulence is defined as the rough, sometimes violent atmospheric conditions encountered by airplanes. There are basic safety rules that are adhered to by airports and airlines across the world and these minimize the possible dangers of turbulence. Most injuries result when these rules are ignored.

What are the Levels of Turbulence

Light turbulence is described as momentary, slight erratic change in altitude and attitude. It may include a slight rapid rhythmic bumpiness. During light turbulence, unsecured objects may shift but food services should continue and walking is possible.

Moderate turbulence is similar to light turbulence but is of a greater intensity. Changes in altitude and attitude occur but the aircraft remains totally in the control of the pilots. Food services may continue but walking is difficult and unsecured objects will shift.

Severe turbulence is characterized by large abrupt changes in altitude and attitude. It commonly causes large variations in speed and the aircraft may be momentarily out of control. Food services and walking are impossible during severe turbulence.

Extreme turbulence is when an aircraft is tossed about and it is virtually impossible for the pilot to remain in control. There is a real chance of injury to unrestrained passengers.

What Causes Turbulence

There are various causes of turbulence which can be grouped as follows:

• Quick changes in air movement
• Disturbed air flows over mountainous regions
• Jet streams
• Thunderstorm activity
• Cold or warm weather fronts
• Wake turbulence which is the trail of disturbed air an aircraft leaves behind it

The jolts and bumps of turbulence are caused by moving from one air stream to another. Clear air turbulence is referred to as CAT and this occurs in clear skies. It is difficult to detect on radar and is best avoided by following reports from pilots who have just passed through the area. This turbulence can be dangerous as it is often unexpected and people may not be fastened into their seats.

What Injuries Result from Turbulence

Modern aircraft are built to withstand turbulence and most injuries are caused by passengers not wearing their seatbelts. If an airplane moves into downward moving air, it will drop with the current. Anything not fastened down inside the aircraft - including passengers - will be tossed around. In severe cases, people may strike their heads on the roof of the cabin.

How do Commercial Pilots Handle Turbulence

As far as possible, pilots seek to avoid turbulence and give passengers a smooth flight. This is done in the following ways:

• Avoiding areas of thunderstorm activity
• Taking notes of earlier flights that report areas of CAT
• Flying at higher altitudes - turbulence is generally less severe above clouds
• Flights are generally smoother at night as there is less convective movement

Turbulence can be distressing and uncomfortable but is generally not life-threatening. The best way to prepare for it is to keep seat belts fastened while seated and don't walk around if the aircraft is experiencing any level of turbulence.

Recommended reading: Airline Pilot - A Guide to Good Practices and Techniques, Old Sausage Publishers, 2007, ISBN 978-0-473-11891-4