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Crosswind Landing

What is a crosswind landing?
I always thought crosswind landing is cool. For those who don’t know what a crosswind is: A crosswind is a wind condition when the prevailing wind is blowing across the runway. From Encarta: “a wind that blows across a particular route, flight path, or direction of travel”.

Crosswind Landing

Why do a crosswind landing?
Landing in this conditions can be tricky and dangerous. This is not normal because normally planes land into winds. For example, a plane is approaching Runway 14 but suddenly the wind veers, and now is blowing from 320. Normally it would circle and land at Runway 32.

What if the wind is blowing 230 or 050? If the plane flies straight, it will definitely not get to the centerline. Maybe it will touchdown at the left or right of the runway. This is why it is necessary to do a crosswind landing.

Normally the wind will blow about 60 degree. Sometimes the crosswind component can get up to 40kts. The limitation for a 737 for a crosswind landing is 35kts for takeoff and landing. It’s the wind component that counts. That means if the wind is 60 degree off your runway heading, you can have a max wind of 40kts. Because sin60×40kts = 35kts. If you have a full 90 degree wind then its 35kts.

How to land in a crosswind condition?
Below is some guidelines given by Boeing for a crosswind landing. These guidelines are based on steady wind meaning there is no gust. These winds are measured at 33ft Tower height for a runway 148 feet in width. Basically there is 3 landing technique. Crab, De-Crab, and Sideslip technique.

De-Crab

The objective of this technique is to maintain wings level and runway centerline during approach. Offset the nose into the wind and maintain wings level and aim for the runway. You might feel funny drifting towards the runway. The trust component will cancel of the crosswind component, so you will actually fly to the runway. Right before the flare, kick the opposite rudder (downwind rudder) to eliminate the crab and maintain wings level. Land.

Crab

Its basically the same with the De-Crab technique, except u land while crabbing and you have to correct for runway centerline after landing. This technique is bounded by a lot of speed restrictions and not recommended.

Sideslip

This is a little bit advance. The purpose of this technique is to maintain extended centerline so that the main gear lands first on the runway centerline. The initial phase of the approach is flown using the Crab technique to correct for drift. Then move the wing into the wind and apply sufficient opposite rudder (downwind rudder) to make the plane maintain its centerline.

A touchdown is accomplished with the right main wheels touching down just before the left wheels. Over controlling the axis must be avoided because over-banking could cause the engine nacelle or outboard wing flap to contact the runway/ground.

In strong crosswind conditions, its sometime necessary to add some crab technique with the sideslip technique.

Alternative crosswind landings
Below is a technique not discussed in the Boeing Flight Crew Training Manual. I saw it once in a video somewhere. It requires a very experienced pilot to execute this maneuver.

As u can see its very hard to judge this maneuver. You can only hope that the wind brings u to the centerline. Remember there is the vertical separation to consider too. When to flare? When to land? How far is it form the runway? Will the wind bring me to the centerline? Its obviously hard to judge the distance from the runway when its not infornt of you.

Videos of crosswind landing.
Below are some examples of the crosswind landing found at YouTube.

Amazing crosswind videos by the 747SP and 777-200.

Video of Singapore Airlines in Zurick Switzerland RWY 14 doing a crosswind landing.

Will / Can a crosswind landing go wrong?
Anything can happen, crosswind landings will increase he pilot’s workload. If anything goes wrong like this video, always go around.

This is a crosswind landing attempt of a TAP Airbus 321 at Lisbon airport. The landing was aborted and the pilot chose to ‘go around.’

I know there are many more methods of crosswind landings. Actually, it doesn’t really matter if u want to do a Barrel Roll or anything during approach. As long as u get the centerline at touchdown.

More crosswind videos at http://forum.flydamnit.com/index.php?topic=54.0