Turbulence is a common experience for airline passengers. It can range from minor bumpiness that’s barely noticeable, to jolts severe enough to throw unbuckled passengers out of their seats. Understandably, many people wonder if turbulence has ever caused a plane to crash. The short answer is yes, but it’s extremely rare. In the history of commercial aviation, turbulence has directly caused very few crashes and passenger deaths. However, it remains a concern for airlines and pilots work hard to avoid areas of potentially dangerous turbulence.
What is turbulence?
Turbulence refers to irregular and disturbed airflow in the atmosphere. It occurs when bodies of air moving at different speeds meet and cause eddies, gusts and other types of air movement. Turbulence can happen at any altitude and causes bumps or jolts to aircraft passing through the affected area.
There are several main types of turbulence:
Thermal turbulence
Caused by uneven heating of the Earth’s surface. As the surface is heated by sunlight, it warms the air above it. The warm air rises, mixes with cooler air above and causes eddies and gusts.
Mechanical turbulence
Occurs when wind flows over hills, mountains, buildings or other obstacles. These disrupt the flow of air and cause eddies in the wind flow.
Clear air turbulence
Caused by wind shear across jet streams. Jet streams are fast flowing, narrow air currents high in the atmosphere. When winds change speed or direction across jet streams it creates shearing and turbulence.
Wake turbulence
Forms behind aircraft as they fly through the air. The wings generate pair of counter-rotating vortices trailing behind the plane that can be very turbulent.
How does turbulence affect aircraft?
Turbulence affects aircraft in a few key ways:
– It causes bumpiness and shaking that can fling around passengers and crew if they are not buckled in. This can lead to injuries.
– It causes sudden vertical drops that can make passengers feel momentarily weightless. These drops can cause injuries if passengers are not seated and belted.
– It creates loads and stresses on the aircraft’s wings, control surfaces and fuselage. This can lead to structural failures in extreme cases.
– It can cause the aircraft to roll from side to side or pitch up and down, requiring the pilot to constantly correct the attitude.
– In severe cases, it can lead to loss of control if the turbulence exceeds the capacity of control surfaces to compensate. The aircraft can be flipped, spun or experience extreme rolls/pitch.
Have planes crashed due to turbulence?
The overall risk of crashing due to turbulence is extremely low. Modern airliners are designed to withstand very heavy turbulence. However, there have been some rare incidents where turbulence was determined to be the primary cause of a crash:
BOAC Flight 911
In 1966, a Boeing 707 broke up in midair and crashed into Mt Fuji in Japan, killing all 124 people on board. The accident investigation concluded that extreme turbulence from the jet stream caused the aircraft to break apart.
United Airlines Flight 826
In 1997, a Boeing 747 approaching Japan experienced severe turbulence from Typhoon Becky. The turbulence flipped the aircraft upside down, forcing the pilot to make an emergency landing with several injured passengers.
American Airlines Flight 587
In 2001, an Airbus A300 crashed into a Queens neighborhood just after takeoff from JFK airport in New York. All 260 people on board were killed along with 5 people on the ground. The investigation found that wake turbulence from a preceding jet caused the First Officer to overuse rudder controls, leading to in-flight break up.
So while it’s possible, the chances of crashing due to turbulence are about 1 in a billion. For comparison, the odds of being struck by lightning in your lifetime is 1 in 15,000.
Turbulence accident statistics
Looking at accident statistics paints a clearer picture of just how rare turbulence-related crashes are:
Commercial aviation accidents 1959-2020
| Total accidents: | 2097 |
| Total fatal accidents: | 1018 |
| Accidents caused by turbulence: | 3 |
| Fatal accidents caused by turbulence: | 2 |
So out of over 2000 total airliner accidents in 60+ years, only 3 were caused by turbulence. And of over 1000 fatal crashes, only 2 were attributed to turbulence.
Odds of dying in a plane crash
Your lifetime odds of dying in any kind of plane crash as an airline passenger are about 1 in 11 million. That includes all potential causes – pilot error, maintenance issues, sabotage, weather etc.
When you isolate turbulence as the cause, the odds are exponentially smaller. Some estimates peg the odds of being killed by turbulence at 1 in 600 million. You’re vastly more likely to die in a car crash, from cancer or by falling down stairs.
How pilots avoid turbulence
Avoiding potentially dangerous turbulence is a major priority for airlines and pilots. Here are some of the main ways they reduce turbulence risks:
Weather radar
Onboard weather radars detect precipitation and winds to help identify areas of turbulence ahead of the aircraft. Pilots can see storm systems and jet streams on radar and steer clear of them.
Pilot reports
Pilots regularly report back to air traffic control when they experience turbulence. This allows following flights to be aware of turbulence at specific locations and altitudes.
Turbulence forecasts
Meterologists make specialized forecasts predicting where turbulence will occur based on weather patterns. Pilots check these forecasts and plan routes to avoid zones of high turbulence risk.
Seat belt signs
When approaching areas of expected light or moderate turbulence, pilots turn on the seat belt sign to ensure passengers are buckled in and not injured.
Altitude changes
If aircraft encounter unpredictable areas of turbulence, pilots can maneuver to fly higher or lower to escape it. Turbulence often only exists at certain altitudes.
Slowing down
In moderate to severe turbulence, pilots may slow the aircraft below normal cruising speed. This reduces the risk of damage from turbulence loads on the aircraft.
Diverting from course
For severe turbulence that cannot be avoided, the captain may decide to divert onto a different route or to a nearby airport to prevent potential damage to the plane. Diversions for turbulence are rare.
Turbulence flying tips for passengers
While pilots do everything possible to circumvent turbulence, it can’t always be avoided. Here are some tips for airline passengers to stay safe if you encounter bouts of mid-flight bumpiness:
– Keep your seat belt fastened whenever seated, even if the seat belt sign is off. Turbulence can strike unexpectedly.
– Stow away loose items like phones, books and coats so they don’t fly around and strike others.
– Be extra cautious walking around the cabin, use seat backs for stability.
– If sleeping, use blankets or jackets to avoid injury if jolted awake by turbulence.
– Stay away from unoccupied seats that lack a buffer body for protection.
– Follow crew instructions, they are trained for turbulence response.
– Report injuries immediately to the flight attendants.
– Avoid unnecessary movement, stay seated with your seat belt tight.
Conclusion
Turbulence has directly caused very few crashes throughout the entire history of commercial aviation. While bumps from turbulence may be frightening, pilots are skilled at avoiding dangerous turbulence and modern planes are engineered to withstand heavy loads. Following crew instructions and always wearing your seatbelt significantly reduces the risk of injury. The overall odds of being in a crash attributed to turbulence are about 1 in 600 million, so there’s no need for excessive worry. Flying remains the safest way to travel even with occasional turbulence.