Calm guide
Can turbulence crash a plane?
Modern airliners are built and certified to carry far more force than turbulence normally produces, with a 50% safety margin on top, and the accident record reflects it: in 111 US airline turbulence accidents from 2009 to 2018, not one aircraft suffered substantial damage.
When the aircraft drops suddenly, the mind jumps to the worst. The engineering answer is calmer, and it is written into law.
Built for far more than you feel
In the United States, every airliner is certified under the rules in 14 CFR Part 25. Three of them answer this question directly:
- Strength for gusts. Designers must analyse the aircraft in strong vertical and sideways gusts; the reference gust in the rules is 56 feet per second at sea level, reducing with height.
- Limit loads. The structure must handle at least 2.5 g (two and a half times its weight in normal flight) upwards and −1 g downwards without any harmful permanent deformation.
- A 50% margin on top. The "ultimate load" is the limit load multiplied by a factor of safety of 1.5, and the structure must carry it for at least three seconds without failing.
These are minimums. Then the aircraft is tested.
The wing test
In 2010 Boeing loaded a 787 airframe to 150% of the most extreme forces it is ever expected to see in service. The wings flexed upward about 7.6 metres (25 feet) and held. Tests like this are part of how a new airliner type shows it meets the rules before it carries passengers.
What happens in real turbulence
The US accident record is the best real-world check. In its 2021 study of all 111 turbulence accidents on US airlines from 2009 to 2018, the NTSB found no case of substantial damage to the aircraft; 95.5% had no damage at all. The harm was to people who were standing or unbelted when the bumps hit.
Pilots also add margin of their own. When rough air is expected they slow to a recommended turbulence-penetration speed, and the FAA tells airlines to make avoidance a priority in planning, using forecasts and reports from other pilots.
So what should worry you?
Honestly: not the wings. What matters is being seated with your belt fastened when the ride gets bumpy, because that's where nearly all real injuries come from. Read is turbulence dangerous? for the full numbers.
And if knowing helps, look ahead: our forecast shows where and when your flight is likely to meet bumps, and how long they should last.
Questions people ask
How much force can an airliner wing take?
US certification rules require airliners to withstand at least 2.5 times the force of normal flight (2.5 g) without permanent damage, and 1.5 times that, held for at least 3 seconds, without breaking. Boeing tested the 787 wing to 150% of the most extreme loads expected in service; it flexed upward about 7.6 metres (25 feet).
Do pilots fly into turbulence on purpose?
No. Airlines plan around known rough areas, and pilots use forecasts and reports from other aircraft to change height or route. When they do fly through bumps, they slow to a recommended turbulence speed that reduces the loads further.
Why do wings bend so much?
Because they're designed to. A flexible wing absorbs gusts like a car's suspension. The movement you see from the window is normal.
Sources
- 14 CFR 25.337, Limit maneuvering load factors (eCFR)
- 14 CFR 25.303, Factor of safety (eCFR)
- 14 CFR 25.305, Strength and deformation (eCFR)
- 14 CFR 25.341, Gust and turbulence loads (eCFR)
- Boeing, Boeing Completes Ultimate Load Wing Test on 787 (2010)
- NTSB Safety Research Report SS-21/01 (2021)
- FAA Advisory Circular 00-30C, Clear Air Turbulence Avoidance (2016)
We write these guides for passengers, from official and peer-reviewed sources. They are not medical advice and not for flight operations. How our forecast works.