Turbulence is irregular air movement that normally cannot be seen.
The US Federal Aviation Administration identifies several causes, including jet streams, air moving around mountains, weather fronts and thunderstorms. It can also occur in apparently clear skies. This guide explains the basics and the passenger habits the FAA recommends. It does not assess the weather, aircraft or route for your flight.
AI-generated image, not a photograph of a real person or place.
BELT ON while seated
Belt fastened while seated
Low and tight on the hips
Crew instructions come first
Calm habits for a bumpy patch
THE SHORT ANSWER
Uneven air, one simple habit.
Its causes, the clear-sky trap and the one habit the FAA asks for.
THE CAUSE
Air that moves unevenly
The FAA describes turbulence as air movement that normally cannot be seen. It can be created by jet streams, air around mountains, weather fronts and thunderstorms.
Turbulence can occur when the sky appears to be clear. The FAA’s advisory circular for pilots says clear air turbulence is often met unexpectedly and frequently without visual clues.
The FAA advises keeping your seat belt buckled at all times while seated, worn low and tight on the hips, and listening to the pilots and flight attendants.
Pick a moment in a flight to see how the FAA puts it. The bar is full where FAA regulations require the belt, half full where the FAA advises it, and short where the FAA points you to your airline’s own policy.
Based on the FAA pages “Turbulence: Staying Safe” and “Passenger Safety Tips”. The FAA is the US aviation authority. On any flight, the seat-belt sign and the crew’s instructions for that flight come first.
THREE FIGURES FROM THE FAA
Three figures, none of them a forecast.
From FAA passenger guidance and a circular written for pilots.
3
Moments when FAA regulations require the belt
Leaving the gate and climbing after take-off, landing and taxi, and whenever the seat-belt sign is lit. Outside those moments, the FAA still advises keeping the belt fastened while seated.
SEAT-BELT RULES · FAA
100–300 miles
Common length of a jet-stream turbulent area
The FAA’s advisory circular for pilots says such areas are commonly 100 to 300 miles long, elongated with the wind, 50 to 100 miles wide and about 5,000 feet deep, and may persist from 30 minutes to a day.
CLEAR AIR TURBULENCE · FAA AC 00-30C
40 lb
Weight below which the FAA advises a child seat
The FAA recommends an approved child safety seat or device for a child who weighs less than 40 pounds (about 18 kg). For children under two, it calls such a seat the safest place.
CHILDREN · FAA SAFETY TIPS
These figures come from guidance and from the FAA’s description of where turbulence is found. They are not a forecast, a risk score or an assessment of any flight.
FIVE HABITS FROM THE FAA
Simple habits for every flight.
None of these needs special knowledge. They are the FAA’s own recommendations, and the crew’s instructions on the day come first.
Watch the safety briefing
Pay attention to the flight attendants’ safety briefing at the beginning of the flight, and read the safety briefing card.
Buckle up whenever you are seated
Keep the belt fastened at all times while seated, not only when the sign is on. Turbulence can arrive unexpectedly.
Wear it low and tight
The FAA says the belt is meant to sit low and tight on the hips, not the abdomen, to effectively limit the body’s forward motion.
Listen to the crew
Treat the crew’s instructions and the illuminated seat-belt sign as instructions for your actual flight. If you are unsure how to fit your belt, ask the cabin crew.
Follow the cabin rules
Keep to your airline’s carry-on restrictions, and buckle up children in an approved child seat or device.
AI-generated image, not a photograph of a real person or place.
WHY THE SKY CAN MISLEAD
Clear air, unseen movement.
AI-generated image, not a photograph of a real person or place.
The FAA’s advisory circular for pilots defines clear air turbulence as sudden severe turbulence in cloudless regions. One of the principal places it is found is near the jet streams, relatively narrow bands of strong wind in the upper atmosphere. It is often encountered unexpectedly and frequently without visual clues.
The same circular says that wind shear and turbulence are more intense above and downwind of mountain ranges where waves form in the airflow. Pilots and airline dispatchers work with pilot reports and turbulence forecasts made for them. The useful distinction for a passenger is between understanding the phenomenon and predicting a particular journey: this guide explains the first.
QUESTIONS
Questions people ask before flying.
Short answers, each drawn from the FAA sources listed below.
What is turbulence?
The FAA describes it as air movement that normally cannot be seen and often occurs unexpectedly. It can be created by atmospheric pressure, jet streams, air around mountains, cold or warm weather fronts or thunderstorms.
Can there be turbulence when the sky is clear?
Yes. The FAA says turbulence can occur when the sky appears to be clear, and its advisory circular for pilots notes that clear air turbulence often comes without visual clues. A view without clouds does not tell you that the rest of the flight will be smooth.
When do I have to wear my seat belt?
FAA regulations require it when the aircraft leaves the gate and climbs after take-off, during landing and taxi, and whenever the seat-belt sign is illuminated. The FAA also advises keeping it fastened at all times while seated.
How should the seat belt be worn?
Low and tight on the hips, not the abdomen, according to the FAA. That position helps limit the body’s forward motion. If you are unsure how to fit it, ask the cabin crew.
Where should a young child sit?
The FAA says the safest place for a child under two is a government-approved child seat or device, and recommends one for a child who weighs less than 40 pounds. Ask your airline where to find its own guidance for travelling with children.
Can this site tell me whether my flight will be bumpy?
No. This guide explains turbulence in general. It does not assess the weather, aircraft or route for any flight. On board, follow the seat-belt sign and the crew’s instructions.
How should I use the official pages?
Start with the FAA’s turbulence page for the explanation and the passenger precautions, then its weather overview and passenger safety tips. A useful reading note has three lines: the idea you learned, the official source, and any question to ask your airline before travel.
