By Captain Evarest Nnaji

A message for the International Civil Aviation Day.

As we mark International Civil Aviation Day, it is important to reinforce the fact that aviation remains the most reliable, effective, efficient, and safest mode of transportation in the world. Air turbulence may feel uncomfortable, but it is a normal part of flight, one for which aircraft are designed, and pilots are expertly trained.

Air Turbulence remains one of the most misunderstood aspects of air travel. For many passengers, any sudden movement in flight can trigger anxiety. Yet, within the aviation industry, Air turbulence is well-studied, well-managed, and contrary to public perception, rarely a threat to the safety of an aircraft.

What Causes Air Turbulence?

Air turbulence is caused by rough air pockets encountered during a flight. Rough air pockets are derived from air with poor molecules. When an air pocket contains rich air molecules, the sky is clear and devoid of clouds. Clouds form when atmospheric conditions in a section of the sky collect or attract interference components in the form of moisture, mist, fog, smog, steam, dew, condensation, convection, haze, vapour, etc.

The introduction of any or more of these elements into the atmosphere reduces the molecules in the air and creates visible air pockets known as clouds.  Clouds, when formed by the earlier mentioned interference components, then have poor air molecules which, in turn, will not be strong enough to warrant the smooth flow of rich air over an aircraft’s airfoils (wings), thereby causing turbulence.

When clouds form, they contour into different shapes and structures, giving them divergent patterns. Different clouds are named after their shapes and strengths, such as Stratus, Stratocumulus, Cumulonimbus, Nimbostratus, Altostratus, Altocumulus, Cirrus, Cirrostratus etc.

A more troublesome source of air turbulence in flight is thunderstorms.

Thunderstorm is a weather system that includes lightning, thunder, heavy rain, strong winds, and sometimes hail. It can form from large towering cumulonimbus clouds, and can also form rapidly over adiabatic temperature change rate in rising unstable air.

There are four main types of thunderstorms; light, moderate, severe and extreme thunderstorms.

Severe and extreme thunderstorms appear scary and worrisome, but aircraft do not fly through them. Pilots and air traffic controllers avoid them using Radar, Weather reports and Satellite data.

There is also the Clear Air Turbulence (CAT) that can form at any altitude, high or low. CAT has no visible pattern. Therefore, pilots can run into CAT without adequate preparation or forewarning, causing sudden jolting turbulence in flight. But the industry has developed a mechanism known as PIREP which enables the first pilot to encounter CAT, to make a certain immediate pattern of report, letting other aircraft in the route or region to prepare for it.

Aircraft design capability:

Modern aircraft are structurally designed to handle very well all forms of possible air turbulence.

Each aircraft model’s wing-structure, at design stage, underwent a bench-test usually stronger than anything such aircraft can ever encounter in real bad weather flight conditions before certification by FAA and or EASA for commercial production and use. This certification is a without-which such model will never fly in America or European airspace, and by extension, the world over.

So, your aircraft may shake, dip, rock and rattle in flight, but will never fall off the sky due to air turbulence. In addition, pilots are trained to navigate air turbulence safely.

How do passengers handle air turbulence? 

Realistically, the main danger passengers can encounter in air turbulence is the sudden jolts that can cause people to fall or hit their heads on cabin consoles.

Another danger can result in movement within the cabin, which can move the center of gravity (CG) limit of the aircraft, depending on the size of aircraft and amount of movement. Such movements can affect pilots control input and judgment, causing the aircraft not to respond the way the pilot had mastered it.

But all this can be completely avoided by simply ensuring you are seated with your seatbelt fastened.

So, stay calm, keep your seatbelt fastened, the aircraft is built to withstand it, is the rule of thumb.

So next time your flight encounters turbulence or rough patch of air, remember:

It may be turbulent, but it is not dangerous.

Captain Evarest Nnaji is both FAA (USA) and NCAA (Nigeria) licensed pilot, and the Group Chairman of OAS Helicopters, a leading conglomerate in Nigeria’s oil and gas aviation sector, as well as an astute businessman and philanthropist.