Hello Doug,I fly with Air Canada quite often and by now I understand that weatherpatterns have a lot to do with turbulence. My questions is, can turbulence bring the plane down??? Or brake it apart in the air. Silly question but Ialways wanted to know. Thanks. Iwona
Iwona. Thanks for the email.
There are six different types of turbulence and one man made (wing tip vortices from other aircraft).
My first enRoute article some 12 years ago addressed turbulence called, "Why the Bumps?" (see below)
An aircraft is built such that it can handle whatever mother nature throws at it. So, I have yet to hear about an airliner
breaking up in flight due to turbulence.
As far as bringing an airplane down, turbulence near the ground could effectively cause an accident. One type, LLWS (Low Level Wind Shear)
can be dangerous to low flying aircraft. Having said that, most airliners are equipped to tell the pilot windshear is present.
We pilots know what conditions are conducive to turbulence and we consult weather charts, weather reports and receive pilot reports from other aircraft on
a continual basis. We try to give the smoothest flight possible because after all, if it's bumpy, we don't get served either.
All the best, and again, thanks for taking the time to submit your question.
Why the Bumps?
The different types of turbulence
Those bumps sometimes experienced when flying are not caused by air pockets, as is commonly believed. Actually, air pockets do not exist. Sudden movements are caused by disturbed conditions of the atmosphere due to irregular wind currents, or turbulence. There are six different types of turbulence and they can occur during each phase of flight. Fortunately, your flight crew is prepared to avoid all six, thus ensuring your comfort.
Mechanical turbulence occurs when aircraft encounters strong winds blowing over irregular terrain such as hills, trees or buildings. This type occurs near to the ground at less than 1300 metres (4,000 feet). To avoid mechanical turbulence after take off, the pilot will steepen the angle of the aircraft’s climb. When landing, he or she will decrease the aircraft’s speed.
The second kind is known as convective turbulence. During the day, the sun heats up the earth, which then heats the overlying air. The hotter the air, the bumpier the turbulence. Convection, the way that heated air travels upwards in the atmosphere, is at its maximum during the heat of a summer afternoon. Cloud formations are good indicators of the degree of convection at work, and of a pilot sees white, puffy, convective or cumulus clouds,, it is often a sign of turbulence. He or she can then easily avoid it.
When these billowy clouds become taller than they are wide, they are called towering cumulus, and signal the buildup of thunderstorms. Once these clouds are moderately or fully developed, they will show up on the aircraft’s radar-not the clouds themselves, but the rain showers inside. The larger and more intense the rain shower, the more obvious they appear on the radar. Pilots can then avoid them by navigating around the showers.
A third type of turbulence is low level wind shear (LLWS). This occurs as a result of updrafts under a thunderstorm or when winds funnel down a valley. Pilots are familiar with this hazard and avoid flying under a thunderstorm, particularly during take off or landing. Many aircraft now have wind-shear detecting equipment on board, and a number of airports are equipped to detect LLWS. Orographic turbulence occurs when a strong wind blows perpendicular to a mountain range, causing a phenomenon known as a “mountain wave” (orography is the field of knowledge concerned with mountains). By watching for the three types of clouds that may indicate its presence, a pilot can then avoid the bumpier air of a mountain range’s downwind side or climb above it.
A fifth type, called frontal turbulence, is brought on by a sudden change in wind direction due to a weather front. A quick look at the latest weather chart will tell a pilot where these fronts are, as well as the speed at which they are moving.
The last, and perhaps least understood kind of turbulence, is clear air turbulence (CAT). This forms when little to no weather systems are present, and is caused by jet streams- long, thin bands of fast-moving air sandwiched between the first two layers of the atmosphere, usually located at ten thousand metres (33,000 feet). Jet streams corkscrew around the globe like coiling, meandering snakes and occur when two air masses collide. The resulting winds can cause significant turbulence, but can be avoided without difficulty.
The members of your flight crew are always up-to-date on the latest weather reports and forecasts, and are expertly trained to avoid or minimize any discomfort. So sit back and relax; the next bump you experience will be your landing!