How far does a plane drop in turbulence? What the flight data shows

Key facts

• On Singapore Airlines flight SQ321 in May 2024, vertical acceleration swung from +1.35 g to −1.5 g within 0.6 seconds, and the airplane dropped 178 feet over 4.6 seconds. [1]
• That drop took SQ321 from 37,362 to 37,184 feet: turbulence had first pushed it up, so it ended the drop still above its selected altitude of 37,000 feet. [1]
• On Delta flight 56 in July 2025, near thunderstorms, the airplane cycled between about 38,000 and 35,500 feet over two to three minutes, with vertical acceleration between about +1.75 g and −0.5 g. [2]
• Standard gravity is 9.80665 m/s² [3], so a change of −0.5 g held for one second moves an airplane about 2.5 meters (8 feet).
• WMO guidance defines moderate turbulence as changes of 0.5 to 1.0 g at the aircraft's center of gravity. [4]
• In the NTSB's study of US airline turbulence accidents from 2009 to 2018, none involved substantial damage to the airplane. [5]

Feet versus g: why a small drop feels huge

A g is a unit of acceleration equal to normal gravity. In smooth flight you feel 1 g. When the airplane suddenly moves down, the floor briefly stops pushing up on you as hard, and you feel lighter: 0.7 g, say, a change of −0.3 g. That floating feeling in your stomach is your body measuring acceleration, and it's very sensitive to it.

What your body can't measure is distance. Distance depends on how big the change in g is and how long it lasts. For a steady change starting from level flight, the distance is ½ × acceleration × time². Here's what that gives, as simple worked examples [3]:

Real bumps rarely hold a steady value: even on SQ321, the reading swung from −1.5 g back to +1.5 g within 4 seconds [1]. That quick reversal keeps the distances small. So a bump that makes you grab the armrest has usually moved the airplane a few feet, about the height of a room.

What flight data shows: two real cases

Official investigation reports give the best answer, because they read the airplane's flight data recorder rather than people's memories.

Singapore Airlines SQ321, May 2024

The flight from London was cruising at 37,000 feet over southern Myanmar when it met severe turbulence. Singapore's Transport Safety Investigation Bureau reported [1]:

That −1.5 g jolt is far beyond anything most passengers will ever feel, and the bureau said it likely made occupants who weren't belted become airborne [1]. Yet the airplane moved 178 feet, and finished that drop higher than the altitude it had been assigned. The crew diverted to Bangkok and landed [1].

Delta flight 56, July 2025

An Airbus A330 flying from Salt Lake City toward Amsterdam met severe turbulence near thunderstorms at 37,000 feet over Wyoming. The NTSB's preliminary report describes an updraft that carried it up to 38,000 feet over about 20 seconds, then a rapid descent to about 35,500 feet, with the climb-and-descent cycle repeating about three times over two to three minutes. A convective SIGMET, an official storm warning, was in effect for that area [2]. The crew diverted to Minneapolis and landed [2].

Notice the twist: Delta 56 changed altitude by thousands of feet, yet its sharpest g reading (−0.5 g) was much milder than SQ321's (−1.5 g) [1][2]. Large altitude changes come from big, sustained up- and downdrafts inside storms. Sharp jolts come from fast changes in the air. Feet and g are different things.

Is "the plane dropped 1,000 feet" real?

Almost always, no. That number comes from how a drop feels, not from the instruments. The pilots' own scale shows the gap: light turbulence causes only "slight, erratic changes in altitude and/or attitude," chop comes "without appreciable changes in altitude or attitude," and it takes severe turbulence to cause "large, abrupt changes in altitude" [5].

Real altitude changes of that size do happen in rare cases:

• Inside or near thunderstorms, where updrafts and downdrafts are strong, as on Delta 56 [2]. Storm-related turbulence was present in 57.7% of US airline turbulence accidents from 2009 to 2018 [5], which is why pilots fly around storms and why convective SIGMETs exist.
• In mountain waves, where up-and-down currents in the air can reach 2,000 feet per minute [6]. That's a rate over a minute, not an instant drop, and crews plan around it.

Even then, the airplane isn't falling. It's riding a large current of air, with its wings still flying.

Are air pockets real?

Not as holes. "Air pocket" is the everyday name for the sudden sinking feeling, but the air around an airplane is continuous. Turbulence comes from eddies, circular currents of air moving in a different direction from the main flow [5]. When the airplane flies from rising air into sinking air, or the wind changes suddenly, the lift on the wing changes for a moment and you feel the drop. To understand where those currents come from, see what causes turbulence.

Why it feels like falling, and what keeps you safe

Two things make drops feel bigger than they are. Your body notices small changes in g easily. And the back of the airplane can swing more: in one accident the NTSB studied, peak g in the rear cabin was about 0.2 g larger than at the center of gravity [5]. If that bothers you, see the best seat for turbulence.

What keeps you safe is simple. Being seated with the seat belt fastened is the most effective way to prevent a turbulence injury [5]. On SQ321, the bureau said it was occupants who weren't belted who likely became airborne [1]. The airplane itself is built for loads far beyond any of these bumps; is turbulence dangerous? explains the 2.5 g it must carry.

When the plane drops:

1. Keep your belt snug and low across your hips.
2. Breathe out slowly. A long out-breath settles the body; see breathing exercises for flying.
3. Remind yourself of the numbers: a few feet, a few tenths of a g.
4. Follow your crew.

How Sorapuff helps

Sorapuff's bump meter measures what you actually feel: each bump's change in g, from your phone's motion sensors, in airplane mode. It shows the bump next to the 2.5 g the airplane is built for, with a calm needle that doesn't jitter, and after landing the Bump Report shows how much of that margin your biggest bump used. It's free, and it's information, not a safety device: always follow your crew. For the full scale, see turbulence levels explained in g.

FAQ

How many feet does a plane drop in turbulence?

Usually a few feet. A bump that changes g by half a g for one second moves an airliner about 8 feet, and real bumps soon reverse. Even the violent SQ321 encounter in 2024, with a jolt of −1.5 g, showed an altitude drop of 178 feet on the flight data, and the airplane diverted to Bangkok and landed.

Can turbulence make a plane drop 1,000 feet?

Very rarely, and not in an instant. Altitude changes of that size happen in severe storm encounters or strong mountain waves, over tens of seconds to minutes, as the airplane rides large up- and downdrafts. In a 2025 storm encounter, an A330 cycled between about 38,000 and 35,500 feet over two to three minutes. Pilots use storm warnings to stay clear of such air.

Why does it feel like the plane is falling?

Because your body senses acceleration, not distance. When the airplane moves down suddenly, you feel lighter for a moment, which reads as falling. A change of a few tenths of a g is easy to feel but moves the airplane only a few feet. The wings keep flying the whole time.

Is it normal for a plane to drop suddenly?

Yes. Small sudden drops are part of ordinary turbulence: the airplane moves from rising air into sinking air, or the wind changes. Most are light and move the airplane only a few feet. Keep your seat belt fastened whenever you're seated, and the drop will be a moment of discomfort, not danger.

What is an air pocket?

An air pocket is the everyday name for a sudden drop in turbulence, not a hole in the sky. The air is continuous; what changes is its motion, from rising to sinking or from one wind to another. The wing's lift changes for a moment and you feel lighter, then the airplane carries on flying normally.

Sources

1. Transport Safety Investigation Bureau Preliminary Investigation Findings of Incident Involving SQ321 (May 29, 2024), Ministry of Transport, Singapore
2. Aviation Investigation Preliminary Report DCA25LA276, Delta Air Lines flight 56 (2025), NTSB (copy published by Flightradar24)
3. Standard acceleration of gravity, CODATA values of the fundamental constants, NIST
4. Aviation Hazards: Turbulence and Wind Shear, World Meteorological Organization
5. Preventing Turbulence-Related Injuries in Air Carrier Operations Conducted Under Title 14 CFR Part 121, Safety Research Report SS-21/01 (2021), NTSB
6. Mountain Waves, SKYbrary Aviation Safety