Learn why an aircraft points into the wind during a crosswind, how crab angle stops drift and what changes before touchdown.
An aircraft points into a crosswind to create an upwind component of its airspeed that cancels the wind’s downwind drift. This wind-correction angle, called a crab angle, keeps the aircraft on the required ground track—such as a runway centreline—even though its heading and track do not match.
How does a crab angle stop wind drift?
In real-world aviation, a crab works because an aircraft’s movement over the ground is the combination of its velocity through the air and the movement of that air mass. In simple terms: ground velocity = air velocity + wind velocity.
If the wind comes from the left, it carries the aircraft towards the right. Pointing the nose left creates an opposing leftward component, allowing the resulting ground track to remain straight. The aircraft appears to travel slightly sideways to someone watching from the ground, but a properly established crab is not a sideslip through the surrounding air.
Heading is where the nose points; track is the path travelled over the ground. Our explanation of how flight instruments show heading and ground track helps clarify this distinction in a simulator cockpit.
Does the wind turn the aircraft by itself?
No: a steady, uniform crosswind does not automatically rotate an airborne aircraft towards the geographical wind direction. The aircraft moves within the air mass, and its vertical tail keeps it aligned with the local relative airflow rather than with a line drawn across the ground.
The pilot establishes the corrected heading with a coordinated turn, or an autopilot tracking a route calculates the correction. Turbulence and wind shear can produce temporary yaw and roll, but they are separate from the steady crab angle.
On the ground, the situation is different. Because the aircraft is constrained by its wheels, a crosswind pressing on the fin and fuselage can produce a weathervaning tendency that turns the nose into wind.
Is crabbing the same as sideslipping?
No. A crab changes the aircraft’s heading, while a crosswind sideslip uses bank and opposite rudder to keep the nose aligned with the desired ground track.
| Characteristic | Crab | Crosswind sideslip |
|---|---|---|
| Nose direction | Points into wind | Usually aligned with the runway |
| Wing attitude | Approximately level once established | Banked into wind |
| Control balance | Normally coordinated | Into-wind aileron and opposite rudder |
| Typical use | En route and during approach | Final approach, de-crab and touchdown |
How much should the aircraft point into the wind?
The correct wind-correction angle is whatever keeps the required ground track without drift. A stronger crosswind or lower true airspeed requires a larger crab angle; a faster aircraft needs less angle for the same crosswind component.
For a direct crosswind in steady conditions, the simplified relationship is crab angle = arcsin(crosswind component / true airspeed). A 20-knot direct crosswind at 100 knots true airspeed therefore needs roughly 12 degrees of crab. Actual surface wind, wind aloft, gusts and local terrain can make the observed correction different.
- Choose the required track. On approach, this is normally the extended runway centreline.
- Observe the drift. Use outside references or compare the displayed heading with the ground track.
- Turn into wind. Make a small coordinated turn, then return the wings to level rather than holding rudder alone.
- Refine the angle. Increase the crab if the aircraft still drifts downwind; reduce it if the track moves upwind.
Remember that aviation wind directions state where the wind comes from. Wind from the left requires a crab towards the left.
What happens to the crab before touchdown?
Before touchdown, the crab is usually removed or blended into a wing-low sideslip according to the aircraft’s approved procedure. Rudder aligns the nose with the runway while into-wind aileron prevents renewed sideways drift.
Many light aircraft use this wing-low technique through touchdown. Some transport aircraft permit a limited crabbed touchdown, but limits and preferred methods vary by aircraft and operator. For simulator practice, our complete crosswind-landing control sequence covers the transition from crab to touchdown, while the rudder-and-aileron technique for smoother landings explains how to avoid lateral movement at wheel contact.
Once the wheels are down, the wind still matters. Into-wind aileron is normally increased as speed and control effectiveness decrease, while rudder or nosewheel steering maintains direction; see our guidance on controlling the aircraft during the landing rollout.
What crosswind-correction mistakes cause problems?
Most poor crosswind corrections come from controlling heading instead of ground track.
- Pointing straight down the runway: the nose looks right, but the aircraft drifts downwind away from the centreline.
- Using rudder alone to establish the crab: this produces an uncoordinated yaw or skid. Establish the heading with a coordinated turn, then level the wings.
- Holding a memorised angle: wind changes with height and position, so adjust from observed drift rather than relying on one calculated figure.
- Chasing every gust: use measured corrections and watch the developing ground track instead of making large, rapid control inputs.
The correction is right when the aircraft follows the intended path over the ground. The nose pointing away from that path is expected—it is the visible sign that the crab is cancelling the crosswind.