B737 35 knot Crosswind take off. Which wing drops on lift off?

[Bruce Waddington]

Hi All,

Years a go I was taught that when starting a crosswind take-off you needed no aileron into wind. As the speed increased and you got a feel for how much rudder was needed to keep on the centerline you would then start to put in some upwind aileron. The point being that if you needed a small amount of rudder you needed a small amount of upwind aileron and if you needed a large amount of rudder you needed a large amount of upwind aileron.

This, explained the wise old Captain, would stop me from doing three things;

1. Having too much aileron selected as the airspeed increases which will actually cause the aircraft to turn into wind even more than the crosswind tries to make it and therefore will require more rudder than is really required to keep staight on the runway. The correction for this overcontrol can make for some interesting moments during the take-off run and just after lift off.

2. Having too much spoiler deployment for the conditions which can also cause the aircraft to turn into wind even more than the crosswind tries to make it with the same issue as above.

3. Having not enough aileron selected which will allow the upwind wing to start rising around 100 kts and also create some interesting moments during the correction process.

There is no 'preset formula' for aileron displacement during a crosswind take-off. Too much is just as bad as not enough. See how much rudder you need to keep straight and then, early in the take-off run, put in enough aileron to keep the wings level. Adjust as required if the wind changes or gusts.

regards,

Bruce Waddington